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Frontend DesignerTraining Guide

Product Information

Version 6.0

© 2003 Meta4 Spain, S.A. All rights reserved.

WARNING: This manual is protected by copyright law and international treaties. Permitted use of this document is limited to its use in connection with the product and any unauthorized use will be pursued to the full extent of the law. Do not copy, modify, reproduce or distribute without the owner's permission.

Meta4 PeopleNet © 1999. Meta4 Spain, S.A. All rights reserved.

Meta4KnowNet © 1996. Meta4 Spain, S.A. All rights reserved.

Meta, Meta4Mind, Meta4 PeopleNet, Meta4 KnowNet and Meta4 e-mind are registered trademarks belonging to Meta4 Spain, S.A.

Other company names, products, or services are registered trademarks or trademarks of their respective owners.

Meta4Spain, S.A.Centro Europa EmpresarialEdificio RomaC/ Rozabella, 8Ctra. de La Coruña, km. 24,20028230 Las Rozas, MadridSPAINhttp://www.meta4.com

Publishing Date: 2nd January, 2003.

Last Modified Date: 2nd January, 2003.

Table of Contents

INTRODUCTION 1

n Course objectives 1

n Prerequisites 2

n How to use the training guide 3

Using the guide during the course 3

Using the guide after the course 4

n Designing presentations in the development cycle 5

n About this course 7

OVERVIEW 9

n Overview objectives 9

n Main Concepts 10

1 INTRODUCING THE FRONTEND DESIGNER: BASIC CONCEPTS 13

n Introduction 13

How to access the functionality for this lesson 14

n Conceptual definitions 16

i

Contents

Frontend Designer window structure 16

New Presentation 17

Previewing a presentation 18

Central pane: Visual Designer 18

Inserting a new form in a presentation 18Shifting from Form1 to Form2 19Changing the grid size 20

Central pane: OBL editor 20

Editing the OBL code of a presentation 20Closing the OBL editor 21

Control palette 23

Adding controls from the control palette to a form 23Saving a presentation 25Adding controls to a form from the "Insert Component" option 25First approximation to basic properties of visual components 27

Setting properties in design time using the Properties dialog box 27

Control Label 30Control Image 31Control Link 32Control Urlbox 32Control Combobox 32Control Checkbox 33Control Groupbox 33Control Checkboxgroup 34Control Textbox 34Control Button 34Control Slider 35

Setting properties in design time using the OBL editor 35

The syntax checker 36Saving code from the FrontEnd Designer and inserting code into the OBL editor 38Saving OBL code from the FrontEnd Designer 38Inserting code into the OBL editor 39

Presentation Explorer 40

Adding visual and non visual components with the explorer. Events and Actions. 40Components as containers 42Nodes and their hierarchical interpretation 43

Introducing OBL 44

What is behind a running presentation? 45

ii

Contents

The Properties dialog box and the programming scenario 47

Overview 47Case 1 47Examples for case 1 49Case 2 52Examples for case 2 52Example 53General hints 54

Some exceptions 55

Control Split 57Toolbars 57Menus 58

n Review questions 60

n Lesson summary 61

Lesson Key Points... 61You should be able to .... 61

2 BUILDING LOGIC INTO PRESENTATIONS: MORE OBL 63

n Introduction 63



Hierarchy means logic 66

Referring to properties of other objects 66

Absolute referencing 66Relative referencing 67Absolute reference facility 68

Changing properties in runtime 72

Action_set 72Action_call - Methods 73Namespace 74

Connecting presentations 74

Connecting through an Extends component 74Connecting through an Action_task 74

Presentation context and context variables 75

Transferring variables - Context vs. Runtime variables 77

iii

Contents


n Lesson summary 80

Lesson key points... 80You should be able to... 80

3 ADVANCED CONTROLS AND FUNCTIONALITY 81

n Introduction 81



Tabstrip, Panel and Scrollpanel 84

Changers and trees. Virtual forms. 85

Changers 85Exercise 86Trees 87Exercise 87Virtual Areas 87

Multi language text 89

Some important properties 90

Implicit Flow control; Explicit Flow control (Action_goto) 91

Action_dialog 94

Exeblocks 94


n Lesson summary 97


4 CONNECTING TO META4OBJECTS 99

n Introduction 99



iv

Linking components to Meta4Objects 102

Data properties 102Loading options 103

Controls closely related to Meta4Objects 105

Text property. Multi language options. Hard coded text vs. data bound text. 109Toolbar navigation buttons. First approach. 110Multinode Meta4Objects. 111Introducing the Record Insert Wizard 112Action_value 116Action_list 117Patternbox 118Nodestatus 118Table 119Further steps on data related Actions and Toolbarbuttons 121Toolbar groups 122Advanced data related Actions - Use of Action_call - Action_dataprops 123Action_method 125Action_bp 127Using Split controls 128Mimic control 1285.2.17 Back to changers 130

Action_script, Checkbox and Checkboxgroup 131

Action_script 131Checkbox control 132

Listgroup 134

Structure of the Listgroup control - The Function control 137General properties of Listgroup 139Function properties 140Passing data Part I - Mainargs and Mainobjs 140Passing data Part II - Targetitems and Targetobjs 142Function Zoom 144Function Clear 144Function List 145Label 146Textbox (non virtual fields) 147Textbox (virtual fields) 147List button 148Advanced properties of the ZLG 148The Record Insert Wizard and the ZLG 151

Working with tracks 154

Toolbar Navigation Groups 158Specific patterns 159Steps in the preload 161

v

Conditional object construction 163

Multicompany features in presentations 165

Default and customized presentations 165Customized presentations - params group type element for toolbar 167Customized presentations - button type element for toolbar 168


n Lesson summary 170


5 EXPLORING WHAT THE FRONTEND DESIGNER WIZARD DOES 171

n Introduction 171



Main structure 174

SplNodeFields_Up 174

SplNode_Up 177

SplNodeFields_Down 178

Logic in Default Presentations 179

The Tree as a main controller 179Tabs 180Footer section (SplNodeFields_Down) 180

Multicompany in default presentations 181

n Lesson summary 182


A APPENDIX: BRIEF SUMMARY OF SOME CONTROLS 183

n About this appendix 183

n Controls for containers 184

vi

B APPENDIX: MOUSE EVENTS 189


n Mouse events 190

C APPENDIX: EVVALIDATE: TRIGGERING MECHANISMS 191


n Evvalidate 192

Triggered when losing focus 192Triggered when clicking 192

D APPENDIX: DATA-RELATED EVENTS 193


n Data-related events 194

E APPENDIX V: OTHER EVENTS 195


n Other events 196

F APPENDIX VI: SOME PROPERTIES 197


vii

n Properties 198

Properties set #1 198Properties set #2 199Properties set #3 199Properties set #4 200Properties set #5 201Action 201Mousecursor 202Image 202

G APPENDIX VII: EVENTS CONTAINED IN COMPONENTS 205


n Events 206

H APPENDIX VIII: METHODS 211


n Methods 212

I APPENDIX IX: SOME MORE COMPONENTS 217


n Some more components 218

Action_copy 218Action_dataprops 218Action_datatrack 220Action_execute 220Action_method 221

viii

Frontend Designer

Introduction

The Frontend Designer course will develop your skills and background knowledge required to effectively develop presentations for the windows client in Meta4 applications such as Meta4 PeopleNet and Meta4 KnowNet.

The purpose of this course is to introduce you to the benefits, features, and functionality of the presentations used in the windos interface within applications that use the underlying Meta4 technology and tools.. You will have opportunities to practice with the software and identify key benefits and efficiencies gained by using the Frontend Designer.

Upon completion of this course, you will be able to do the following:

n Master the Frontend Designer.

n Create well-designed presentations customized to your company´s needs.

n Create effective interfaces for your Meta4Objects

n Describe what the Frontend Designer Wizard does when creating default presentations for Meta4Objects.

Course objectives

1

To successfully meet the course objectives, you should meet the prerequisites listed below.

Prerequisites

Other external knowledge

Windows environment

Relational Data modeling

Familiarity with programming algorithms and programming languages

Meta4 knowledge Find more information in...

Core Tools Training Guide - Data Modelling Training Guide - Developing Basic Functionality Training Guide - Developing Advanced Functionality with Meta4Objects

2

This training guide is designed to support you in learning about the Frontend Designer. Each Meta4 course consists of several lessons. Each lesson is designed to streamline and accelerate the learning process. Our lessons contain the following standard sections:

n IntroductionsDescribe what you will learn in the lesson and how it will benefit your organization.

n Conceptual definitionsExplain Meta4 terms and functionality often using figures and examples.

n Guided activitiesProvide an opportunity for you to practice using the Frontend Designer. We support you through the use of business scenarios and detailed step-by-step solutions.

n Additional featuresDescribe complementary Meta4Mind Set utilities available to aid you in developing functionality.

n Unguided activitiesProvide an opportunity for additional practice using Meta4Mind Set. These activities are more complex and challenge you to use what you have learned throughout the lesson.

n Review questionsCheck your mastery of the lesson objectives.

n Lesson summariesReview the knowledge and skills you learned in the lesson.

Using the guide during the course

Throughout this course, use this guide to follow along with your instructor. It includes pictures or diagrams your instructor may refer to in the class presentation. Take additional notes throughout this book. During a guided activity, you can refer to the instructions to the activity. At the end of a lesson, check to see whether you are ready to complete the next lesson by answering the review questions and reviewing the summary.

How to use the training guide

Introduction 3

Using the guide after the course

After attending this course, you can refer to the definitions, examples, and step-by-step instructions to help you while working with Meta4 applications using the Frontend Designer.

4

Whenever you use Meta4 development tools to create functionality, you are in fact developing business functionality that has already been previously identified and defined in the Customer Requirements Analysis phase of the Meta4 Project Implementation Methodology. Once the Customer Requirements have been identified and the product installed, then in the Customization phase of a project implementation, you can start building the required functionality, using the Meta4 development tools. There is a loosely defined procedure for customization using the tools, this is known as the development cycle.

The very first step in this development cycle is to build the data model for describing the specific customer data and its relationships to support Meta4Objects, the cornerstone of the application business functionality.

Designing presentations in the development cycle

Figure 1. Positioning presentation designing within the development cycle of the customization phase

CORE TOOLS

VERTICAL TOOLS

CustomerRequirements

Time Relational Data Model

Meta4Objects

ANALYSIS

DESIGN

Events

VTVT

VT

VTVT

VT

CUSTOMIZATIONPHASE

REQUIREMENTSANALYSIS PHASE

Frontend Designer

Introduction 5

Once the data model and Meta4Objects that implement the desired functionality are created, the next step is to present the information to the user. This is where presentations come into play. These form the interface to the application and its functionality particularly in the windows client.

A poorly designed presentation can spoil the entire underlying process, no matter how good it is. Creating effective, well-designed presentations dramatically enhance the usability of your application and improve the efficiency of the department that has to work with the application.

6

The course content is organized sequentially according to the way a you build a presentation in a Meta4 application using the Frontend Designer. You will be guided through the concepts and steps involved by following a business case or several activities if appropriate.

About this course

Overview A high level structure of this module and the key elements forming the different processes the module offers.

Lesson 1: Introducing the Frontend Designer Wizard

This lesson is an introduction to the Frontend Designer tool. You will learn the tool interface and start creating your first presentation using some basic controls

Lesson 2: Providing logic to presentations: mode OBL

In this lesson you will study the event-action process underneath presentations. You will start providing more powerful logic to your presentations.

Lesson 3: Advanced controls and functionality

In this lessons you will study more advanced controls.

Lesson 4: Connecting to Meta4Objects

This is a key lesson. Here you will learn how to link your presentations to Meta4Objects.

Lesson 5: Exploring what the Frontend Designer Wizard does

Lesson 5 explores the structure of default presentations created with the Frontend Designer Wizard.

Introduction 7

Frontend Designer

Overview

e

As you know from previous courses the logical architecture of the application is divided in three levels: Database level, Application level, Presentation level. The Presentation level is the user interface to the application. When new functionality is created using the Data Model Designer and or The Meta4Object Designer, an interface has to be created for that new functionality. The Frontend Designer is the tool of Meta4Mind Works devoted to the development of such interface.

In this section you learn the principal processes, concepts, and features of Meta4Mind Set Frontend Designer.

Overview objectives

Objectives

Upon completion of this lesson, you will be able to:

n Understand where presentations come into play in the process of developing new functionality with meta4Mind Set.

n Understand what the Frontend Designer is for, and how can be used to effectively design presentations.

n Have a bird’s eye view of what the learning process in the courswill be.

9

In the process of building up a new functionality inside Meta4Mind Set there comes a point at which the developer wants to use the Meta4Objects already designed. This use of a Meta4Object is always provided trough a presentation. In terms of the Logical Architecture we are entering the Presentation level. This level comprises all software components used to present information to the end user. Thus we shall define the user final interface when we building a presentation.

The execution of a Meta4Object involves the load of the related data, but those data can be shown only if a presentation is used. What this means is the need of a presentation any time we want to ’see’ a Meta4Object.

A Presentation is the main interaction unit between the end user and Meta4Mind. Any time a Meta4Object is invoked presentations are needed and this also comprises internet/intranet and work flows.

Meta4Mind helps the developer build up ’default’ presentations by means of a wizard. These default presentations enable the developer to choose the

Main Concepts

Figure 2. Steps of the basic "new functionality" process

Data Model DesignerData model

Meta4Object DesignerMeta4Objects

Frontend DesignerPresentation

Task DesignerTask definition

Menu DesignerMenu option

10

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ons

nd act, tool

nt

.

ject

how et,

final aspect of the Meta4Object depending on the desired functionality. You can present a Meta4Object as a usual form, or as a list, or as a filter plus list screen … The wizard is what you have been using in Meta4Object basand advanced courses.

Most of the time changes and modifications to these default presentatiare required. To make this modifications you shall use the Frontend Designer Tool. This tool enables editing and modifying presentations, aalso building up presentations disregarding the wizard. As a matter of fthe Designer Tool can be understood as an independent programmingand we will dedicate some time to learn how to use it.

This two approaches are reflected in the Frontend Designer Tool, for when you enter the Frontend Designer, you are entering a set of differetools:

n The Designer Tool, meant to build up programs in a highly portablelanguage. This also enables the modification of already made presentations.

n The wizard, for constructing default presentations of different kinds

The present course will first lead you trough the Designer Tool as an oboriented programming tool, unrelated to Meta4Object. When the basic aspects of the Designer Tool have been learned, you will learn how to connect with Meta4Objects, gaining practice and familiarity through examples. You will then understand what a default presentation is, and to modify it, no matter its final use (i.e., whether it will be used in intranin a windows client, as part of a workflow...).

Figure 3. Roadmap of the course

Lesson 1.Introducing the FrontendDesigner:Basic concepts

Lesson 4.Connecting toMeta4Objects

Lesson 5.Exploring what the FED

Wizard does

Lesson 3.Advanced functionality

Lesson 2.Providing logic to

presentations: more OBL

Overview 11




Wizard does


Lesson 2.Building logic into

presentations: moreOBL

Introducing the Frontend Designer: Basic concepts

.

The Frontend Designer is the Tool of Meta4Mind Works that allows you to create interfaces for your Meta4Objects, in other words: Presentations.

In this lesson you will be introduced to the Frontend Designer. You will first learn what each of the sections of the FED (Frontend Designer) is for. Once you have gained experience with the FED interface, you will start learning about the basic structure of a presentation, and some of the basic controls that will allow you to implement some elementary functionality.

.

Introduction

Lesson Objectives


n Identify the main components of the Frontend Designer Tool.

n Understand the structure of a very basic presentation.

n Create simple presentations.

n Identify some of the basic controls and their functionality.

13

How to access the functionality for this lesson

Select the following path:

If you select this path the following window opens:

Click the Frontend Designer option on the right panel, or double click the same option on the tree and the Frontend Designer window will open.

Meta4Mind Menu Tree

Mind|Developement Tools|Presentations

Figure 4. Accessing the Frontend Designer

14

In order to fully open the structure of the Designer Tool you need to bring the so called Presentation Browser (or Explorer) to the screen. The Explorer is hidden by default. To open it select the option View|Presentation Browser on the window toolbar.

Figure 5. The Frontend Designer window

Figure 6. The Frontend Designer with the Presentation Browser

Introducing the Frontend Designer: Basic concepts 15

Frontend Designer window structure

In the Frontend Designer window we differentiate the following main sections:

n Window toolbar

n Title bar

n Left pane: Presentation browser

n Middle pane: Visual designer and OBL editor

n Right pane: Control Palette

Throughout the course we will be referring to this sections, so it is important that you get familiar with them.

Conceptual definitions

Figure 7. Frontend Designer window sections

16

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ould in

New Presentation

When you open the Frontend Designer a new presentation is displayed by default.

Notice the that the title bar indicates that it is indeed a new presentation by displaying the message New Presentation. Take a close look at the contents of the Presentation Browser, you’ll see a two node tree. The displayed presentation is at this moment a program. A presentation is a program with a very special piece of code. If we looked at the code of tprogram it would look something like this:

BEGIN The Program

Some code

END

The code in between the BEGIN and END instructions would contain the definition of the components inside the presentation. In our case, this wbe Form1. You can visually see the form in the Presentation Browser orthe Visual Designer (Middle Pane).

A form is a very special component. The windows the user sees when interacting with the application are designed over forms. We will study

Figure 8. New Presentation


n

lp n.

in

rking

een

forms in more detail later in the chapter.

In case a presentation contains a form, its execution will promote the construction of the form in run time. Let´s study how to execute a presentation and how the run time form is constructed.

Previewing a presentation

To preview your presentation select the Tools|Preview Presentation menu option or click the Preview Presentation button on the window toolbar.

Closing the form brings you back to the Designer tool. Be aware of thedifference between the form in design time and run time. The form in rutime is displayed without grid lines. These grid lines are intended to heyou in further steps of the design process as it will be explained later o

You can insert more than one form in a presentation. You will learn thisthe next section

Central pane: Visual Designer

From a design point of view a presentation can be understood as a woarea where different graphical and functional elements are arranged inorder to help (implement) a given functionality1. Those elements are referred to as controls.

The form included in the new presentation is a control contained by thepresentation. Once inserted, the form will act as a visual interface betwthe user and the application.

Inserting a new form in a presentation

Let´s now insert another form in the presentation. To do so follow the instructions.

1. Generally speaking any given functionality. In particular, if you are working inside Meta4Mind Set your functionality has most probably been designed with the DMD and the Meta4Object Designer. The presentation design can help the end user to fulfill that functionality

18

The form displayed in the visual design pane shows handles around the form. Those handles enable changes in the form´s size.

Shifting from Form1 to Form2

Only one form is visible at a time in the visual designer. To shift back toForm1 you can:

Notice that if you click the Presentation node in the Presentation Browser, there is no object displayed in the visual design pane.

a. Right click the Presentation node in the Presentation Browser and select the option New Form

b. The "Form2" will appear in the Presentation Browser and you will see the new form in the visual designer pane.

a. Click the Form1 node in the Presentation Browser or

b. Use the combo box on the window toolbar and select Form1


Changing the grid size

The grid is a design tool that will not appear in run time. Grids will help you design the visual appearance of your forms. To change the grid size of a particular form do the following:

Central pane: OBL editor

The middle pane also acts as an editor. We have already mentioned that the presentation is acting as a program. That program can be represented by the OBL language. The OBL code of the presentation is editable in the middle pane.

Editing the OBL code of a presentation

To edit the OBL code of a presentation do the following:

a. Right click the desired form either in the Presentation Browser or the Visual Designer. A pop up menu will appear

b. Select the option Change Grid Size. A new dialog box will appear.

c. Determine the desired grid size and click OK.

20

The whole presentation can be understood as a sequential execution process and this interpretation is most evident when the OBL code is studied in detail. We will go back to this fundamental topic later in this course.

Our presentation contains two controls: Form1 and Form2. You can see that each control (form) is defined in the OBL code by a "BEGIN Form - END" structure. The OBL in between those two sentences is the OBL code corresponding to each control.

Closing the OBL editor

You will now close the OBL editor for the presentation. You have two possibilities:

a. Right click the Presentation node in the Presentation Browser. A pop up menu will appear.

b. Select the OBL Editor option. The code for the presentation will appear in the middle pane


ion.

the

y of ears

Let´s now open the OBL editor for each of the controls in the presentat

The OBL editor lets you open the code for a number of components atsame time. It will not let you edit duplicate code. If you try to open the OBL code for the presentation at the same time as the OBL code for anthe controls in the presentation (say Form1 or Form2), a message appprompting you to close some OBL editors:

a. Click the Close button in the window toolbar or

b. Select the View|View Editors menu option, select the editor you want to close and click the Close Editor(s) button

a. Right click the Form1 node in the Presentation Browser, and select the OBL Editor option from the pop up menu. The middle pane will show the OBL code for the Form1 control only.

b. Repeat the same process right clicking this time the Form2 node. The middle pane will show a tabstrip with two tabs: one tab for the Form1 control, and another tab for the Form2 control. Each tab contains the OBL code for the corresponding control

22

OBL nd to

to a

r tool erred

are

er

The reason why this message doesn’t appear when we try to open theeditor for Form2, while the OBL editor for Form1 is open is that Form1 aForm2 are disjoint. None is partly or fully contained in the other. In orderopen the OBL editor for the presentation you will have to close the OBLeditors for Form1 and Form2.

In later sections of the course you will learn that controls can be addedform or a presentation either visually (using the Visual Designer), or adding their corresponding "BEGIN control_name END" structure directly in the OBL code of the presentation.

Control palette

We have already spoken about controls and components. The Designehas a great number of components, some of them visible. These are refto as controls. The Control Palette in the right pane includes the most common visual components (controls).

The controls listed in the palette and a brief description of their meaningincluded at the end of the manual.

Up to now the only control we have dealt with is the Form control. Forms are very special visual components that act as direct containers for othvisual components.

All the controls listed in the palette can be added visually to a form by clicking and dragging.

Adding controls from the control palette to a form

Follow the steps to add a button control, a label control and a textbox control to Form1 and a label control and a texbox control to Form2

Figure 9. Closing OBL Editors


a. Click the button control on the control palette, then click the form and drag the mouse to determine the dimensions of the control.

b. Use the Label button and the Text Box button in the control palette to place the controls on the form

c. Select Form2

d. Insert a label and a text box repeating the process explained above

24

Saving a presentation

In order to save a presentation, click the Save button on the window toolbar. The Save dialog box will appear. We recommend that you use the CXX_NAME_OF_YOUR_PRESENTATION syntax, where XX are replaced with your initials. So if your name is Mike Smith and you want to name your presentation Example_1, then the name would be as follows: CMS_EXAMPLE_1. We also recommend that you save your presentations with the Owner ID 101.

Adding controls to a form from the "Insert Component" option

Another way of inserting a control to a form is by means of the Insert Component menu option. This is a pop-up menu option that appears when

e. Notice how the explorer reflects your actions by inserting an icon for each of the controls you insert in the presentation.

Figure 10. Saving a presentation


right clicking the icon of the form in the presentation browser.

Follow the steps to insert a button in a form.

a. Right click the Form1 icon in the presentation browser.

b. Select the Insert Component option. The Component List window will appear.

c. Select the Button icon and click OK. A new button will appear on the left-upper corner of the form.

26

n by

First approximation to basic properties of visual components

Components have a number of properties. By giving certain values to these properties you define the final behavior of the component. Simple and intuitive properties are the Size, Backcolor or Font, among others.

You can access the properties of a certain component in design time in two different ways: through the Properties dialog box or through the OBL Editor.

Setting properties in design time using the Properties dialog box

Any component in a presentation has several properties which are set to a certain default value as soon as the component is included in the presentation.

Any time we insert a new component in the presentation by selecting it from the Insert Component menu option, the Alias property is automatically set by the designer tool. This alias is the logical name you shall use inside the program to invoke the component.

Let´s start off with a brand new presentation. Create a new presentatioclicking the New button on the window toolbar.

d. Drag the button to the desired position in the form. Use the handles to resize the control


Notice that after inserting the new form in the presentation, the component is added to the tree in the left pane (presentation browser) with the name Form2. This name is a property whose value has been set to Form2 by default. You have not chosen it.

The set of properties of a given component can be seen in design time by right clicking the component (either on the visual designer pane or in the node representing the control in the browser) and selecting the Properties option from the pop-up menu.

The following figure displays the Properties window for the Form control.

a. Click the New button on the window toolbar to create a new presentation

b. Select the Blank Form option from the New Presentation dialog box.

c. Insert a new form in the presentation. Right click the Presentation icon in the presentation browser and select the New Form option from the pop-up menu.

28

You can change (or set) a property value just by overwriting the existing one on the corresponding row of the Property dialog box.

For example let´s change the background color of the form.

Figure 11. Properties dialog box for the Form control


following are a number of exercises that will help you gain experience in the management of control properties.

Control Label

a. Save this presentation as CXX_EXERCISE_2_1.

b. Insert a label in the form.

c. Open the Properties dialog box for the label and change the following properties:

a. In the Properties dialog box for the form, click the three-dotted button located in the Backcolor row. A new dialog box will appear.

b. Select the new color for the background

c. Click the OK button on the Properties dialog box.

30

d. Click the OK button in the Properties dialog box.

e. Save your presentation.

f. Preview your presentation.

Notice that some properties are only seen in run time. That is the case for the Mouse and Tooltip properties, which can be noticed when moving the mouse over the label.

g. Finally, change the value of the properties Enabled and Visible from 1 to 0, and test the effects.

h. Save your presentation.

Control Image

a. Insert an Image control in the form.

b. Set the Image property to the value #Four. This value (#Four) refers to a so called "fixed" image. You can find the rest of fixed images in Appendix VI.

c. Insert a second image control. Set its Image property to b_mapusa.bmp. See that the image is not seen in design time. This is a non fixed image, i.e. a file stored in the disk. Save the presentation and preview it. Notice how fixed images include the # character in their name whereas non fixed images do not.

d. Open the Properties dialog box for Image2 and change the property Stretch to True. Save and preview the presentation.

Property New Value

Text My Label

Font Tahona, 10pt, Underline

Borderstyle 1

Alignment 2

Forecolor any color (except for black)

Mousecursor Hand

Tooltip This is a label


Control Link

a. Insert a Link control in the form.

b. Change the following properties of the control:

c. Save and preview your presentation. Test the link.

Control Urlbox

a. Insert a Urlbox in the form.


Notice that this control shows the page in design time.

c. Save and preview your presentation.

Control Combobox

a. Insert a Combobox control in the form.

b. A combobox usually displays a list with several options from which to select. To get this functionality in run time, use the Values property of the combobox.

Notice that there are no spaces between the values separated by commas.

One thing is the list of values that the end user sees in run time in the

Property New Value

Text Linking to Meta4

Tooltip Click to open

Url http://www.meta4.com

Property New value

Align Bottom

Url http://www.meta4.es

Property New Value

Values Monday,Tuesday,Wednesday,Thursday,Friday

32

combobox, and another is the actual values that the combobox uses internally when selecting a specific option. For example, suppose that you want to map Monday with the value 1, Tuesday with the value 2 and so on, so that whenever you select the option Monday, the combobox stores the value 1 instead of the string "Monday" (why you may want to do this will become more clear in further examples). You can do this using the Listitems property of the combobox.

c. Modify the following properties of the control:

Control Checkbox

a. Insert a Checkbox control in the form.


Value = 1 means that the checkbox will be checked when running the presentation.

c. Reset the Value property to 0 and see the effects is run time.

Control Groupbox

a. Insert a Groupbox in the form.

b. Insert a label and two checkboxes in the groupbox.

c. Try to move (in design time) the groupbox around the form. Notice how the controls inside the groupbox move with it.

d. Preview the presentation.

e. Change the following properties of the groupbox:

Property New Value

Values 1,2,3,4,5

Listitems Monday,Tuesday,Wednesday,Thursday,Friday

Property New Value

Text Check this option?

Value 1


Notice that disabling the groupbox means disabling all the controls contained in it.

Control Checkboxgroup

a. Insert a Checkboxgroup in the form.

b. Insert two checkboxes in the checkboxgroup.

c. Preview the presentation.

Notice that the checkboxes are acting as option buttons (radio buttons) in run time. A set of checkboxes (as the ones seen in the previous section) can be checked all at the same time. A set of option buttons allows the selection of only one option per set (those inside the same checkboxgroup).

Control Textbox

a. Insert a Textbox in the form.

b. Change the following properties of the control.

Control Button

a. Insert a Button in the form.

b. Change the following properties for the control:

Property New Value

Text This is a group

Enabled False

Property New Value

Text My text

Font Arial, 12pt, Underline

Tabindex 1

Tooltip First in getting the focus

34

Control Slider

a. Insert a Slider in the form.

b. Change the following properties for the control:

Setting properties in design time using the OBL editor

Properties can also be set and changed in the OBL editor. You should be aware that a number of properties do not appear in the Properties dialog box, and they can only be changed using the OBL editor.

Property New Value

Text Click

Font Bold

Tabindex 2

Tooltip Second in getting the focus

Image #Currency

Property New Value

Forecolor any color (except for blue)

Maxvalue 30

Tabindex 3

Tooltip Third in getting the focus

Value 10

Tickfrequency 2

Orientation 1


Close now the OBL editor for the form by clicking the Close button on the window toolbar and open the Properties dialog box for the form. You will see that the Mousecursor property has been changed to "Hand".

Remember that any changes introduced with the OBL editor have to be applied before they can take place. You apply the changes by clicking the Apply button on the window toolbar. Notice also that whenever you do some modifications in the OBL code for a component, an asterisk * appears on the tab. That asterisk warns you that you have made some modifications but have not applied the changes yet. Click the Apply button to apply the changes. The asterisk will disappear.

The syntax checker

When the OBL editor is being used for writing code you can check the program syntax before applying the changes.

The integrated syntax checker is activated by clicking the Check syntax button on the window toolbar. This triggers a syntax inspection in the selected OBL tab.

The syntax checker inspects the proper spelling of the OBL code and the validity of properties and values, at a rate of about 1000 lines per second. In case the spelling is correct a message box with the ’Syntax Successful’ message is displayed. If the code contains errors a sub window is created at the bottom of the OBL Editor pane, listing the errors encountered in the checking process.

a. Create a new presentation

b. Right click the Form1 and select the OBL editor menu option. The OBL code for the form will appear in the middle pane.

c. Add the following statement to the code: Mousecursor = "Hand"

d. Click the Apply button on the window toolbar for the changes to take place.

36

tice

Feedback about errors comprises the following information:

n Line number in the OBL code where the error has been encountered

n Error identifier (Error number)

n A description of the specific error

n Total number of errors inside the checked OBL block

In the example shown in the figure above a number of errors where encountered inside an Action_set block. The original OBL code is displayed in the top half of the screen. Notice that the " character is missing at the end of the second line. The third line begins with a misspelled ’set’ property name. Finally, an Evclick was inserted into this block, which represents an Action like component. This is an illegal insertion, for actions do not accept events inside. You will learn more about actions and events in further lessons of the course.

The lower part of the screen displays the error window generated after the syntax checking process. You can follow up the errors with it. The OBL editor also shows the position of the cursor (in terms of Line Number and Column Number) in the Status Bar. This enables a fast localization of the listed errors.

Double clicking an error line highlights the OBL line where the error was encountered, thus this is a second method for identifying error lines inside the program. The figure below displays the situation where the line containing error nº 5 (it appears as a selected line) is double clicked. Nohow the ’BEGIN Evclick ev1’ line is bold typed in the upper half of the screen.

Figure 12. Errors in the OBL code


Do not forget to apply the changes before exiting the OBL editor pane, even when a "Syntax Successful" message has been displayed.

Saving code from the FrontEnd Designer and inserting code into the OBL editor

The fact that presentations can be interpreted in the OBL language opens the possibility of storing OBL code in a file, and to a certain extent the rearrangement of OBL code as if it were a text file.

Saving OBL code from the FrontEnd Designer2

When the OBL editor is being used you can save a selected range of OBL code by selecting the Edit|Save Selection menu option.

Figure 13. Errors in the OBL code II

2. You will learn that presentations stored as disk files can be invoked by means of the STFORM.PTCMFTASK.

38

This opens a ’Save As’ dialog box. The file stored will contain the selected code as if it were a common text file, i.e. ASCII format. Two file extensions can be chosen, ’.obl’ and ’.txt’. They happen to be identical but the ’.obl’ extension might be helpful to identify the text files that contain OBL code.

Inserting code into the OBL editor

The files saved in the previous section can be inserted in a presentation, when its OBL code is being edited. To do so just select the Edit|Insert File menu option. The text in the file will be added to the code contained in the current OBL editor tab.

Figure 14. Saving OBL code

Figure 15. Save As window


Presentation Explorer

The third pane in the Designer Tool is called the Presentation Explorer or Presentation Browser. It is of great help when designing and also for understanding basic aspects of presentations.

We suggest that you open the presentation CXX_EXERCISE_1 while reading this section. Edit the OBL code for the presentation and pay special attention to the Explorer tree.

In every presentation there is an underlying hierarchy of components acting as containers for other components. In the first presentation that you created, forms acted as containers for buttons, text boxes and labels, while forms were contained by the presentation.

This is extremely meaningful to the understanding of presentations and we will come back to this point at the end of this lesson.

At this moment just be aware of how the Explorer reproduces this container/contained behavior at any level, in terms of parent nodes (controls acting as containers for some other controls) and child nodes (controls being contained by another control).

Each branch in the Explorer represents a parent component.You can add components to a parent component.

Adding visual and non visual components with the explorer. Events and Actions.

Not all the components available in the designer tool are included in the control palette. In fact, many of them are non visual components, i.e. they have nothing to do with visual design, but provide the mayor part of the logic inside the presentation. Those non visual components are, mainly, Events and Actions.

Events, actions, and in general non visual components, bring your ’visual’ presentations to live. You can access the non visual components that can be inserted in a specific component by:

1. Selecting in the explorer the node representing the component you are going to use as a container.

2. Right clicking the selected node.

3. Selecting the Insert Object option from the pop-up menu.

The list of components is displayed in a window.

This is exactly what we did at the beginning of the course in order to include a form in a presentation.

40

Do the following exercise where you are prompted to insert two non visual components: one of type Event and the other of type Action.

Exercise

a. Insert an Evclick component in the Button1 control. The Evclick is a non visual component.

b. Save an preview your presentation. Nothing will happen when you click the button. Why?, you have not programmed what happens when the user clicks the button. At this point the program recognizes the click event for the button (you have done that by inserting the Evclick component), but you have not specified what has to happen when the event is invoked. You do that in the next step.

c. Insert an Action_message component in the Evclick component you created in the previous step. Action_message is also a non visual component.

d. Save and preview your presentation. If you click the button now, a dialog box will appear.

Notice that not a line of OBL has been typed. Edit the presentation’s OBL code and notice the changes.

Notice the structure:

Button1

Evclick1

Action_message1

Action_message is a non visual component that triggers a message box which is displayed by default with no text and an OK button. Other options can be implemented with the following properties of Action_message:

n Text = "My Message Text"

This will display a message box with the "My Message Text" message.

n Buttonflags = X

Where X stands for a number from 0 to 5. This will let you choose the buttons you want to be displayed in the message box. The meaning of the different options is explained in the table below:

Buttonflag OK Cancel Abort Retry Ignore Yes No

0 X


An OBL code as the following:

BEGIN Action_message Action_message2

Text = "OOOO"

Buttonflags=2

END

will display the following message box:

e. Add now another button to Form1.

f. Make this button open a third Form (it will be called Form3).

g. Save and preview your presentation.

In terms of the "Button

Event

Action" structure,

n Which is the role being played by Form3 in this example?

n Compare the behavior of Form2 and Form3.

Components as containers

In the above exercise you have noticed how the container/contained

1 X X

2 X X X

3 X X

4 X X

5 X X

Figure 16. Example of Action_message

Buttonflag OK Cancel Abort Retry Ignore Yes No

42

problem is of the greatest importance for OBL programming. In fact, it will help you understand the keystone of OBL programming.

In order to get functionality in our example we have used three different kinds of components:

n Visual components: Button1, and Form3.

n Non visual components:

n Evclick: for making the button able of triggering some process.

n Action_message: for telling the program what to do, i.e. ’show a message’.

In general, presentations must be understood as programs composed of these three elements:

n VISUAL COMPONENTS

n EVENTS

n ACTIONS

Generally speaking if you want a visual component to ’react’ to some event in order to execute some other process you should follow the structure:

1. Select the visual component.

2. Insert the kind of event that will trigger the process.

3. Translate the process into actions that must be sequentially contained inside the event.

If you try to add the ’Action_message’ action inside Button1 without the Evclick1 nothing will trigger the action although it is in the program.

Nodes and their hierarchical interpretation

When referring to a given component inside a presentation the Explorer tree gives you the complete reference name of that component.

As an example, in a presentation like the one in the figure below the text box would be referred to as: Presentation/Form1/Groupbox1/Tabstrip1/Tab1/Textbox1


This is exactly the path given by the explorer. Notice that if there is some non visual component in between the presentation node and the component you want to refer to the only way of getting the complete dependence is by means of the Explorer. That is the case for a form being called from an Evclick inside a button.

Introducing OBL

OBL is built up of three levels:

1. LEVEL ONE: EVENTS

2. LEVEL TWO: ACTIONS

3. LEVEL THREE: VISUAL

Understanding this structure helps in getting a global idea of what we are doing when programming in OBL.

Figure 17. Example of component path

Figure 18. OBL levels

EVENTS

ACTIONS

VISUAL

FORMS

44

an file file

e. tion

You will learn that there are a couple of OBL elements which do not lie exactly inside any of the above mentioned categories, being of the greatest importance for programming purposes.

When writing an OBL program we have to obey the following structure:

An event marks the beginning of certain actions, which are the elements we use to execute commands. Events are contained inside visual components.

Appendix I shows a number of controls and the related objects that can be inserted inside them.

What is behind a running presentation?

Events and actions are ’mortal components’. Visual elements are ’immortal components’. What this means is that when executing an OBL program, any non-visual element dies away. At the end, just the visual components survive, with their related OBL code.

An OBL program begins with an event, but it has to be a special one in order to be independent of any visual component, for at the beginning of the execution no visual component has been created yet. This special event will be the Presentation object that will act as a global container.

According to this we can understand a presentation (which is nothing else than a special event) as a sort of flow process that contains a series of actions.

Events act as triggers for a set of actions to take place. It’s like runningMSDOS bat file, consisting of commands. The event would be the bat itself, which is the 'object' that can be run. And the execution of this bat triggers the sequential execution of the commands it contains. Those commands would act as Actions do.

A bat file 'dies away' when it reaches its end. But the effects can endurThe same happens to a presentation. Enduring elements of a presentaare, among others, the visual interfaces the end user sees.

Figure 19. OBL program structure

BEGIN Event

END

BEGIN Action...

END


Where is that visual interface? Where do visual components lie? How do they take part in presentations?

We have already said that events are contained inside visual components, exception made for the ’Presentation event’. But we still need a link between our initial event (the presentation) and, for instance, a textbox appearing on the screen. Some element connecting an event with a visual component able to contain other visual components an subject of being contained by the Presentation. This very special component is the Form.

Forms act as elements between visual components and actions. Its visual side is obvious. Its action side means the appearance of the visual components it contains, when the presentation has been executed.

As forms are visual components they endure after the presentation is over.

This is why a presentation’s OBL code will follow an structure like:

BEGIN Presentation PresentationX

BEGIN Action ActionXXX

…

Figure 20. Presentation structure

BEGIN Presentation

END

BEGIN Event BEGIN Action

… ENDEND

BEGIN Event BEGIN Action

… ENDEND

Visual components

events

actions

Form

46

thout

ou

u that

tton,

bs

END

BEGIN Form FormX

…

BEGIN VisualComponent CompX

BEGIN Event EventX

BEGIN Action ActionX

….

END

END

END

END

END

The Properties dialog box and the programming scenario

You have already learned how the Properties dialog box edits most of the properties of a given component, enabling the assessment of values withe need of the OBL editor. An 'F4' shortcut to this dialog has been implemented. This Properties dialog box has a wider scope and functionality which is very much related to the programming paradigm yhave just gone through.

Overview

The Properties dialog box shows additional tabs, apart from the one yohave used. These tabs enable the insertion of components into the oneowns the Properties dialog box. Thus for inserting an event inside a buand then an action into that event (remember the VISUAL-EVENT-ACTION scenario) you no longer need to use the explorer twice. The whole insertion can be carried out from the initial Properties dialog.

Generally speaking the new Properties dialog is structured as follows:

Case 1

If the component can contain events the Properties dialog has three ta


n Properties Tab: it includes the list of all the properties.

n Events Tab: it contains a list of events supported by the initial object. If one of this events has already been included into the component it will be shown in bold type.

n Component Tab: Any component that has been inserted in our initial object is listed in this tab, in zone 1 (see figure below). A new component can be included from this dialog by just pressing the Add button (zone 2). This opens the Component List dialog (the same one that is displayed through the Insert Component option).Components can also be removed by means of the Remove button. Finally, the arrow buttons in zone 3 enable changes in the list order. What this means in terms of run time effects is a change in the order in which those components will be executed. This is reflected by the value of the Execorder property. Be aware that the change in the Execorder property is not refreshed automatically in the Explorer although it will be applied in run time, and if you inspect the OBL code you will see that the code blocks change in position according to the specified Execorder.

Figure 21. Properties dialog box: Properties

Figure 22. Properties dialog box: Events

Properties Tab Component Tab

Events Tab

48

Examples for case 1

n Forms

Forms can contain several events, and also a number of non-event like objects. Thus you have the following tabs in the Properties dialog:

Figure 23. Properties dialog box: Components

Figure 24. Properties of the Form control

1

2

3


n Buttons

Buttons also contain events. Furthermore this control can ONLY contain event like components. So the situation is as follows:

Figure 25. Events available for the Form control

Figure 26. Components available for the Form control

50

Figure 27. Properties of the Button control

Figure 28. Events available for the Button control


Case 2

If the component can not contain events the Properties dialog box has only two tabs.

Examples for case 2

n Presentation

Presentations do not contain events, as they are event like components themselves3. Their Properties dialog box is structured as follows:

Figure 29. Components available for the Button control

Figure 30. Properties dialog box without the events tab

3. Presentations can contain presentations, but as we explained earlier in the course this is just an exception in the whole programming scenario.

Properties TabThe usual list ofproperties andtheir values

Component TabContains the list withthe objects that havebeen inserted into thiscomponent.

52

Example

Here you will implement the following well-known functionality: when clicking on a button a message appears.

Figure 31. Properties of the Presentation program

a. Add a button to the initial form and open its Properties dialog box.

b. Click the Events tab. The tab only contains the Evclick event.


General hints

The Properties dialog box contains a list of the components already inserted in the current component. This list is displayed when accessing the Components Tab. The arrow buttons in this tab enable changes in the order of execution in an easy and effective way.

The whole ’VISUAL-EVENT-ACTION’ programming scenario is reflected in this Property dialog box. This helps in the understanding of the underlying programming paradigm. It also avoids undesirable errors and fulfills a more ergonomic use.

The whole hierarchy of objects represented by the explorer can be accessed from the Property dialog, enabling an ordered inspection, modification and insertion of objects.

c. Click the button on the right of Evclick to insert a click event. The Evclick Properties dialog box will open.

d. Click the OK button in order to make effective the Evclick insertion

e. Insert an Action_message into the Evclick component. To do so, open again the Evclick Properties dialog box, and select the Components tab.

f. Click the Add button.

g. Select the Action_message component and click OK.

h. Insert a second Action_message.

i. Save the presentation as CXX_31_EXAMPLE_1.

j. Change the text property for each of the Action_message to:

n This is the first message

n This is the second message

respectively.

54

Some exceptions

All the former visual that contains an event + event that contains an action picture works well in general terms. There are some exceptions to this rules. The following tables summarizes the behavior of the most common components.

Visual Component

Contains visual components

Contains actions

Contains events

Button Yes

Textbox Yes

Treenode Yes Yes

Rectreenode Yes Yes

Groupbox Yes Yes

Itemlabel

Nodestatus

Tab Yes Yes

Image

Link

Patternbox

Combobox Yes

Urlbox

Changer Yes Yes

Toolbarbutton Yes Yes

Splittblock Yes Yes

Extern Yes

Slider

Label Yes


Action Component


Contains actions

Contains events

_bp

_call

_cmf

_copy

_dataprops

_datatrack

_dialog

_edititem

_execute

_filter

_goto

_help

_insrecord

_list

_listtrack

_method

_message

_notify

_set

_script

_task

_tasklet

_value

Form Yes Yes

56

Control Split

There are two controls of this kind; Splitthorizontal and Splittvertical.

Follow the steps to better understand these controls:

a. Add both types of Split controls to Form1. Preview the presentation and test the new controls.

b. Look at the Explorer. Notice that a couple of Splittblocks have been inserted into each Split control.

c. Right click on the Splitthorizontal node and see what you can insert in this control.

d. Right click any of the Splittblock nodes and see what you can insert in them.

Toolbars

To insert a toolbar in a form you can click the Toolbar button on the Control Palette.

a. Add a Toolbar to Form1.

Event Component


Contains actions

Contains events

Event Yes (Forms) Yes Yes (Presentations)

Evclick Yes (Forms) Yes Yes (Presentations)

Evdbclick Yes (Forms) Yes Yes (Presentations)

Evfocuslost Yes (Forms) Yes Yes (Presentations)

Evmouseover Yes (Forms) Yes Yes (Presentations)

Evvalidate Yes (Forms) Yes Yes (Presentations)

Presentation Yes (Forms) Yes Yes (Presentations)


b. Open the OBL code of the Toolbar, you will see:

BEGIN Toolbar Toolbar1

...

BEGIN Toolbarbutton Toolbarbutton1

Text = "Toolbarbutton1"

END

END

Notice the structure in the Explorer Tree and in the OBL code. See that a Toolbarbutton control is included into the Toolbar as happened before with the Split controls.

To insert buttons in a toolbar you must follow these steps:

Menus

Menus are inserted through the OBL editor. The OBL syntax for such a

a. Open the Properties dialog box of the Toolbar. In the displayed Tabstrip, click the Buttons tab.

b. Click the Insert button. You will get to the following window:

c. Give values to the button properties:

l Name: CXX_SAVE

l Image: XSAVE

d. Click the OK button.

58

control is:

BEGIN Menubar MyMenu

BEGIN Menu MyFirstMenuOption

Text = "Option1"

BEGIN Menuitem MyFirstMenuItem

Text = "Item1"

END

END

END


Check your understanding of the current lesson by answering the following review questions:

1. List each of the sections that make up the Frontend Designer tool

2. What is the difference between fixed and non fixed images?. How do you differentiate them?

3. What is the meaning of the properties: Values and Listitems of the combobox?

4. Which are the three main types of components?

Review questions

60

Lesson Key Points...

Summary of key points in a bullet format...

n Frontend Designer Interface: Window toolbar, Title bar, Presentation Browser, Visual Designer, OBL editor, Control Palette.

n Presentations are a very special type of programs.

n Presentations contain visual and non visual components.

n Components can be classified as: Events, Actions and Visual components. Events and Actions are non visual components.

You should be able to ....

Lesson summary

á Create presentations based on forms, and give them the look you desire.

á Implement elementary functionality through your presentations.

á Open up other presentations and understand the main structure.

á Export presentations to text files, and import them back to the Frontend Designer.

á Display messages on screen as the result of the click of a button, or other events that you may wish to implement.





Wizard does




Building logic into Presentations: more OBL

If you review what you have achieved so far, you may thing that you have created very basic presentations, however, and even though you are right, you must have by now a clear understanding of the philosophy underneath a presentation. From now on you will learn how to do more complex the presentations. This learning process is a lot easier than the process you have already gone through.

Introduction

Lesson objectives


n Alter the code supporting a presentation.

n Change properties in runtime.

n Change the program flow of a presentation.

n Refer to a property of a component from outside the OBL code corresponding to that component.

n Differentiate between the two referencing options: Relative and Absolute.

n Call other presentations already created from your presentation

n Use context variables as a way to pass values from one presentation to another

63





Meta4Mind Menu Tree



64

Remember to show the Presentation Browser on the screen. To open it select the option View|Presentation Browser on the menu bar.


Building logic into Presentations: more OBL 65

In order to gain more power in your presentations you will learn now how to type code inside your OBL. Usually that code will be added to an Action block, as those represent the fundamental unit of work inside a presentation.

You will be able to change properties in runtime, change the program flow and refer to a certain component’s property from outside the OBL block of that component. That will teach you how to provide logic to a presentation.

Hierarchy means logic

If you go back to some of the exercises we have done in the previous lesson you will see how the hierarchical structure brings some logic into the presentation. A certain flow can be attained just by ordering the components in a proper way.

Referring to properties of other objects

A common action inside a presentation is changing an object property in runtime. To do so you have to learn first how to address the object and its properties.

Absolute referencing

Each object is identified by the path it inherits in the Explorer. We call this path the object’s absolute reference.


66

The absolute reference of some objects in the presentation shown in the figure above is listed in the table below. The figure also shows the presentation in runtime.

Properties are addressed using the dot operator. Here is an example:

n Addressing the Backcolor property of Textbox1:

/Presentation/Form1/Tabstrip1/Tab1/Groupbox1/Textbox1.Backcolor

Relative referencing

There is another way for addressing objects inside a presentation. We will explain it with an example.

Open again your CXX_EXERCISE_1 presentation. If you are to address an object from another object you have a source and a target object. Suppose you want to address the Textbox2 control from Evclick2. That means:

n SOURCE OBJECT: Evclick2n TARGET OBJECT: Textbox2

Figure 34. Absolute referencing

Object Alias Absolute reference

Button1 /Presentation/Form1/Button1

Textbox1 /Presentation/Form1/Tabstrip1/Tab1/Groupbox1/Textbox1


In order to find the proper reference we suggest that you do the following:

a. Localize both objects in the Explorer tree.

b. Localize the first common node for both the target and source object.

n Textbox2 is contained in the Form2 node, which in turn is contained in the Presentation node.

n Evclick1 is contained in Button1, which is contained by Form1, which in turn is contained in Presentation.

n Thus the first common node is the Presentation node.

n Build the relative path from the source object, each time you ascend a level add a "../" symbol, until you reach the first common node. From that node write the absolute path for the target object.

../../../Form2/Textbox2

Absolute reference facility

When referring to another object inside a presentation two ways have already been explained: using absolute references and using relative references.

Here you will be introduced to the FrontEnd Designer reference facility, which enables the generation of a given component’s path in an internal way. You will be able to paste this absolute reference in any part of the presentation where it is needed.

To illustrate this facility you will use the CXX_EXAMPLE_1 presentation. In this presentation you must have already inserted two Action_message

Figure 35. Relative referencing

68

components into a Button’s Evclick event. Now you will construct the following functionality:

a. Add a Textbox with no text, into the Form. The message shown in Action_messge1 box will no longer be fixed. It will display the text typed inside the textbox in runtime. To do so you can use the following design.

b. Insert an Action_set with the following assignment:

*V*MiVar:=[*O*/Presentation/Form1/Textbox1.Text]

To do so follow the steps:

c. Change the Text property of the Action_message to [*V*MiVar]

d. Select the component (in the example the Textbox1 control), either in the Explorer or in the Design pane.

e. Right click on the selected component. A pop-up menu will appear. By selecting the Copy Component Path option the component’s absolute reference, i.e. the string *O*/Presentation/Form1/Textbox1, is created and sent to the clipboard.You have the same functionality in the Edit menu option.


Read the next section (changing properties in runtime) to fully understand all the steps taken in this example.

You can also drag and drop the component’s path if the OBL editor is open. The former example would be carried out in the following way:

a. STEP 1: Open the OBL code of the target block.

b. STEP 2: Drag (from the explorer) and drop (in the OBL code block)

Add the rest of the components and get the functionality described at the beginning of this example. Save and test your presentation.

Finally let´s just point out that this absolute reference facility has an ’F5’ shortcut.

f. Open the Action_set Properties dialog box and double click in the Set textbox. Now write the beginning of the Set sentence, i.e. *V*MiVar:=

g. Press Ctrl+V to recover the path

*V*MiVar:=*O*/Presentation/Form1/Textbox1

h. Add the.Text property to the above expression

i. Complete the process by inserting square brackets.

*V*MiVar:=[*O*/Presentation/Form1/Textbox1.Text]

Figure 36. Dragging a component´s path in the OBL editor

70

ation , as a te

it

Further options concerning this absolute reference facility can be displayed if the drag-and-drop process is triggered with the right mouse button. In that case the process shown in the above figure would yield the situation represented in the screenshot below.

Paste the component path here option is equivalent to using the drag-and-drop with the left mouse button, it copies the component’s absolute reference.

The Paste component code here option however replicates the whole component´s OBL code. In our example that would result in the code shown in the following figure.

The Cancel option just cancels the process.

The whole drag-and-drop process can be carried out using one presentas a source of OBL code and a second one, with its OBL editor openedtarget. This is most of the times meaningless in terms of getting absolureferences, for the Explorer structure can vary significantly in both presentations. But in terms of duplicating OBL code from a whole blockis extremely useful.

Figure 37. Pasting a component´s path in the OBL editor

Figure 38. Pasting a component´s code in the OBL editor


Changing properties in runtime

Suppose you want to change the initial color of a text box with the click of a button. That means changing the Backcolor property of a textbox control in runtime. To do so just bear in mind the two fundamental concepts you just went through:

1. The structure: ’VISUAL COMPONENT

EVENT

ACTION’

2. How to address an object from another object.

Action_set

n Action_set: Syntax.

BEGIN Action_set ActionSet1

Set = "*O*ObjectReference.PropertyToChange := NewValue"

END

n In order to practice, build a new presentation with a button and a text box. When clicking the button the textbox text must change. Please follow the steps.

72

Action_call - Methods

n Action_call invokes a method supported by the component. The syntax is the following:

BEGIN

Sentence = "*O* ObjectReference.PropertyToChange(NewValue)"

END

n In order to practice repeat the previous exercise changing the Action_set by an Action_call

You can find the methods supported by a great number of components in Appendix VIII

a. Create a new presentation.

b. Insert a button control, and Evclick component in the button, and an Action_set component in the Evclick.

c. Insert a textbox in the form

d. Edit the Action_set Properties dialog box.

e. Set the Set property to the value:

*O*/Presentation/Form1/Textbox1.Backcolor:=30000


Namespace

Notice that in any of the above actions the chain *O* must be added at the beginning of the object reference. This chain means that the following reference points to a presentation object.

This is the first element of the Frontend namespace. The table bellow contains the elements of this namespace. You will learn how and when to use them in the following sections and lessons.

Connecting presentations

Calling a presentation from another presentation is more or less a common task and there is more than one way of doing it.

Connecting through an Extends component

A first way of invoking a presentation from another one uses an special object called Extends.

n Extends: Syntax.

BEGIN Extends Extends1

Idinstance = "IdentifierOfThePresentationYouWantToRise"

END

Connecting through an Action_task

The second way uses the OLE interface TaskInt.TaskInterface which is the basic task interface.

The task you will use is called STFORM.PTCMFTASK which is the primary task for the presentation’s engine. It enables the triggering of any presentation no matter whether it is stored in the data base or in the disk.

Variable Object type

*O* Presentation object

*V* Runtime or presentation variable

*C* Context object

*F* Fixed value

*D* Data object

*T* Data object belonging to the connected track

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You execute this task inside the presentation by means of the object Action_task.

n Action_task: Syntax

BEGIN Action_task ActionTask1

Class = "NameOfTheTaskYouWantToExecute"

END

n Example:

BEGIN Action_task RisePresentation

Class = "STFORM.PTCMFTASK"

END

If you execute this code, no presentation will be raised. Somehow you have to tell the STFORM.PTCMFTASK task which presentation you want to raise. You will learn to do that in the following section.

Presentation context and context variables

If there is any task parameter needed, which is usually the case, it has to be stored in the presentation’s context, because tasks use context variables as parameters.

A context can be understood as the zone where context values can be stored to be used later on either by the presentation in which they have been defined or in another presentation.

By default contexts are inherited. What that means is basically that unless you state the opposite a second presentation that has been started from the first one will work with the same context.

Figure 39. Presentation context

BEGIN Presentation Pres1...

ThisIsAContextVar...

END

CONTEXT

ThisIsAContextVar

Here some contextvariable is created Here it is stored


You can break the context inheritance by setting the second presentation’s Localcontext property to TRUE.

From that moment the presentation with its Localcontex set to true has a new context not connected to its parent presentation’s context.

Context variables are named in the following way:

*C*NameOfTheContextVariable

Where the string *C* means that we are referring to a context object.

You can assign a certain value to a given context variables using the Action_set in the same way as you did with presentation objects. That is:

BEGIN Action_set SetValue

Set = "*C*AnyContextVar := AnyValue"

END

In your case the name of the presentation you want to start is a parameter needed by the task. Thus first we have to create a context variable whose value will be the name of the presentation. There is an special context variable reserved for such purpose: *C*#SYS_IDINSTANCE#. Thus the

Figure 40. Context variables

Figure 41. Context inheritance: local context



END

CONTEXT

ThisIsAContextVar


GetTheContextVar...

END

The context is common

Broken link



END

CONTEXT

ThisIsAContextVarBEGIN Presentation Pres2Localcontext = True

.

.

. GetTheContextVar

.

.

.END

NEWCONTEXT

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code must be:

BEGIN Action_set SetPresNameToContext

Set = "*C*#SYS_IDINSTANCE# := "IdOfNextPresentation""

END

Here is a summary of the steps needed to fulfil the whole process:

STEP 1.- Transfer the name of the second presentation to the context:

BEGIN AnyAvaliableEvent MyEvent1



END

END

STEP 2.- Order the ’rise presentation’ task

BEGIN AnyAvaliableEvent MyEvent1



END

BEGIN Action_task RisePresentation

Class = "STFORM.PTCMFTASK"

END

END

Transferring variables - Context vs. Runtime variables

The other great advantage of contexts is the possibility of transferring values from one presentation to another, through the context, or to store a variable and use it later on the presentation where it has been created.

There is another way of implementing the process we built before. It uses another kind of variable, which is not a context one, but a so called runtime variable.


These runtime variables are named as:

*V*NameOfRunTimeVariable

Values are assigned in the same way as you assigned values to context variables, that is through Action_set.

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Check your understanding of the current lesson by answering the following review questions.

1. What is the difference between absolute referencing and relative referencing?

2. What is the presentation context and what are context variables?. How can you break the context inheritance?

3. What are runtime variables? Which symbol identifies them?

4. What is the Action_call used for?

Review questions


Lesson key points...


n There are two ways of referencing an object is a presentation: relative and absolute referencing.

n You can change control properties through the use of an Action_set or Action_call components.

n To access a property of a component follow the reference to the component.name_of_property structure.

n You can use context spaces to store variables that can be used later on.

n You can also use context spaces and context variables to pass values from one presentation to another.

You should be able to...

Lesson summary

á Change controls properties in runtime.

á Call other presentations from your presentation.

á Pass values to the n presentation invoked.

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Wizard does




Advanced controls and functionality

e, rties

ns.

text s

oto

In this lesson you will study more controls. These controls were not introduced in lesson 1 because they are a little bit more complex, and you needed to start off with simple things. If you have successfully completed the previous lessons, you shouldn’t have any trouble completing this onbecause all you are going to do is learn about some controls and propethat allow you to create more sophisticated presentations.

Introduction

Lesson objectives


n Use advanced controls to create awesome-looking presentatio

n Use the metalanguage capabilities of some controls to display in different languages depending on the language the user halogged in.

n Break the sequential flow of a presentation using the Action_gcontrol.

n Use virtual areas to better design forms and scrollpanels.

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Meta4Mind Menu Tree



82



Advanced controls and functionality 83

Tabstrip, Panel and Scrollpanel

Here is another useful control provided by the Designer Tool: Tabstrip. They are included in the Control Palette.

If you include a Tabstrip in your presentation, you will see that it has to include at least one Tab.

Each tab can be brought to the front of the design pane by selecting it on the Explorer. The pop up menu that appears when right clicking the Tabstrip node also allows for tab selection.

In run time, tabs can be selected by clicking the corresponding tab. In case you want to control the tab to be shown from another control, Tabstrips support two methods:

n Selectedtab(NameOfTab)

n Showtab(NameOfTab)

See appendixes for other important properties.

It must be mentioned here that the Frontend creates overlapping objects on demand, i.e. in run time the unseen objects are destroyed. This results in a lower need of memory and space, but it also means that you have to be very careful when trying to access the properties of an object inside a tab, for it may not be ’alive’ at that moment.

The Panel and Scrollpanel controls act as pure containers. Both act in a very similar way, but the advantage of Scrollpanel is the horizontal and vertical scrolls bars that appear in run time when needed. What this means is that in case the space needed for displaying a number of controls is larger than the size of the Panel, you will not be able to see these controls in run time. But if a Scrollpanel is being used instead of a Panel, scrollbars will be generated enabling the end user to scroll in run time to see all the included controls.

Both the Panel and Scrollpanel controls have the property Contstructif. This property will be discussed later on the course.


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out

Changers and trees. Virtual forms.

Changers

Suppose you want to design a presentation with the following functionality:

n It will show a map with the working centers of your company1.

n There will be some object that enables the user to get a detailed map of an area2 with some additional information (e.g. the address and the head manager’s name)

You could use two different forms, invoke a second presentation or change the image in run time and make some controls visible or non visible depending on what the image control is showing.

The Changer is a control that simplifies this kind of functionality. It lets you implement a number of different visual levels all sharing the same area in the same form. The figure bellow illustrates this concept.

The visual levels we mention can be any of the objects listed in Appendix I (see Changer object). If you construct a level with a container object (a panel, scrollpanel, tabstrip…) a great amount of logic can be added withthe need of changing your form or your presentation.

The most meaningful aspect of changers is the method Changeto, that allows changing from one visual level to another.

WARNIG: Be aware! You must invoke this method from the event you

1. Use the image: "b_mapusa.bmp"

2. Use the image: "b_mapgeorg.bmp"

Figure 44. Changer: visual levels

Changer

1st visual level

2nd visual level

3rd visual level


)"

ill

p of

ners o

want to trigger a change in the changer’s visual level (i.e. a menu option, a button…)

n Changeto: Syntax.

BEGIN AnyAviliableEvent MyEvent

BEGIN Action_call ActCall

Sentence = "*O*TheChanger'sPath.Changeto(VisualLevel_n

END

END

n Example:

Exercise

In order to practice the concepts introduced, do the following small exercise:

a. Build the presentation described at the beginning of this section. It w

show a map with your company's working centers.3

b. There will be some object that enables the user to get a detailed maan area4 with some additional information (e.g. the address and the head manager's name). Use a changer and scroll panels as contaifor the images and the rest of the visual controls. Use two buttons tchange the changer's level.

c. Save and preview your presentation.

Figure 45. Presentation that uses a changer

3. Use the image: "b_mapusa.bmp"

4. Use the image: "b_mapgeorg.bmp"

BEGIN Button Button1 Top = 10 Left = 20 Width = 61 Height = 41 Text = "To level 1" BEGIN Evclick Evclick1 BEGIN Action_call Action_call1 Sentence="*O*/Presentation/Form1/Changer1.Changeto(Level1)" END ENDEND

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This method allows selecting several levels at the same time. The levels have to be separated by commas when the method Changeto is invoked.

Trees

In this section the Tree object will be presented. Trees are build in the following way.

First you establish the area which will act as a container for the tree itself. This area is the Treeview object. As it is the case with the Menubar or the Toolbar controls, it acts as a pure container for the future tree nodes the user includes.

Inside the Treeview object you can only insert a Treenode object which is now a visual component able to respond to an Evclick event.

It is easy to construct a tree reflecting the different visual levels inserted inside a changer and use the Treenodes instead of buttons or any other triggering objects to switch from node to node in the tree.

Exercise

In order to get more familiar with the tree object, do the following small exercise.

Modify the previous presentation and trigger the changes in the changer using the treenodes instead of the buttons. Build the tree hierarchy like:

Virtual Areas

To optimize the use of a changer’s area it is of common use to set the property Align of the contained objects (levels) to All thus forcing the object to occupy the whole area assigned to the changer.

Problem arises when the number of levels inside the changer grows. Or when the complexity of each level design is high. Then this overlapping turns into a source of confusion. Specially is the changer is no longer

Figure 46. Tree hierarchy

Working centers (USA)

Georgia

...


ed t

ign f the

visible because of the Align=All property.

Another common problem encountered when designing is the following: when a scrollpanel is being used you can not control the distribution of the controls that lay outside the scrollpanel’s area. Playing around with each control´s Top and Left properties is a somehow tiresome solution...

Finally, if you use the copy & paste facility for inserting controls into another container, Top and Left properties are inherited in the pasted components, and this can result in a problem similar to the one describbefore. Again, resetting the Top and Left values can solve the problem. Bua more straightforward way is desirable.

In all this situations you will find extremely useful to get a so called Virtual Area of each of the components that act as containers.

To do so, just right click the corresponding treenode in the Presentation Browser (the one corresponding to the container) and select the Virtual Area option from the pop-up menu. Virtual areas are generated as appended forms that are only alive and visible in this 'Form-state' in destime. If they are present in your design, they appear at the lower part oPresentation Browser. The following figure shows a screenshot of a presentation design where virtual areas for Tab1 and Tab2 have been created.

They also appear in the toolbar combobox as if they were forms in the presentation.

Figure 47. Virtual areas

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To display a virtual area in the designer pane you can either select it from the combobox or click its node in the Explorer. Virtual areas are displayed as white forms in order to distinguish them from non-virtual (usual) forms.

You can introduce changes in the virtual form as if you were working in the normal form. These changes have to be applied, as in the OBL Editor. You apply changes by clicking the Apply button on the window toolbar.

To close a virtual form click on the Close button on the window toolbar.

Multi language text

The designer Tool offers the possibility of inserting text associated to a given component in the different languages supported by Meta4Mind Set. This is easily done in the Properties dialog box of that given component. For example, a label inserted in a form can be displayed with a different text depending on the language the user chooses when logging in the application.

The different values of the Text property are given in the Translated Property dialog box that pops up when clicking the button at the right end of the text line.

Figure 48. Selecting virtual areas from the combo box


Multi language text can be tested in design time. Just click the language icon on the status bar and then select the desired language from the pop up menu.

Some important properties

Forms can be designed as Modal forms, i.e., no other form will receive the focus unless the displayed modal form has been closed. By default, this property is set to ’0’ (i.e. false or non modal).

In order to avoid reopening a form twice in run time you can give a non null value to the property Registername of a form. The form will then be created only in case no other form with such Registername is already alive. Register here refers to record.

Startupposition is a property that accepts the following values:

Windowstate lets you decide whether you want the screen to be displayed in a normal way (0), minimized (1) or maximized (2).

When dealing with data base records (next lessons) any change in a value will promote, when the form is being closed, a message asking about saving

Figure 49. Multilingual text

Value Meaning

0 Centers the form in the screen

1 Windows decides

2 Top and left properties are used

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the unsaved changes. To avoid this messagebox when closing the form, change the default value of Askbeforeclose property to ’0’.

Every component has a Grant property based on a bit mask. See Appendixes for details.

Implicit Flow control; Explicit Flow control (Action_goto)

You have already worked with Action_message (see previous sections). There you were presented to the Onok, Oncancel, Onyes... properties. You were told these could be used to control the flow of the program. Here you will learn how this control can be achieved, either from the Action_message component or from some other components provided by the Frontend Designer.

In our programming scenario Actions are the smallest unit of execution. They have to be contained by an event like component. Thus we can understand the sequence of Actions inside an event as an execution block. If left alone, this execution block will perform sequentially the actions it contains. This would be the natural flow.

Figure 50. Sequential flow of actions

End of the execution block

0

1

2

3

Event is triggeredBeginning of the execution

block

Action_message1

Action_call1

Action_set1

4


This sequence can be broken and changed in run time by taking control of the program’s flow. ’Jumps’ in the process shown in the above figure can be performed using for instance the Onok and Oncancel properties of Action_message. This is described in the figure bellow.

Figure 51. OBL code

Figure 52. Onok & Oncancel properties break the sequential flow

BEGIN Evclick Evclick BEGIN Action_message Action_message1 ... END BEGIN Action_call Action_call1 ... END BEGIN Action_set Action_set1 ... ENDEND

Event is triggeredBeginning of the execution

block

Action_call1

Action_set1

End of the execution block

Action_message1OnokOncancel

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Notice that just by giving the Alias of the component you want the flow to jump to in the On* properties this control is achieved.

This On* properties are present in a number of components inside the Frontend designer (see the list below) and many of them will be introduced in the present course. This way of changing the flow is referred to as intrinsic flow control.

n Action_dialog

n Action_edititem

n Action_list

n Action_listtrack

n Action_message

n Action_value

n Action_script

There is an action specifically designed for changing the flow and it is called Action_goto. The syntax of this component is:

n Action_goto: Syntax.

BEGIN Action_goto MyAction

Nextblock = "AliasOfActionInsideTheExecutionBlock"

END

Nextblock is the property where you specify the Alias you want the flow to jump to inside the same execution block. This way of handling the flow is known as explicit flow control.

Figure 53. OBL code

BEGIN Evclick Evclick BEGIN Action_message Action_message1 Onok = "Action_set1" Oncancel= "Action_call1"

... END BEGIN Action_call Action_call1

... END BEGIN Action_set Action_set1

... ENDEND


Action_dialog

This action is intended to display the Open file and Save file windows and the Color, Printers and Font dialogs in run time.

Here are some comments on this action’s properties.

n Dialog. The kind of dialog that is actually displayed in run time is set by means of the value of this property. It accepts:

n Openfile

n Savefile

n Color

n Print

n Font

n Onok & Oncancel. They act in the usual way, i.e. as flow controllers. They accept the alias of the step, in the current execution block

n Filenameobject. It works for Open and Save like dialogs. This is the name of the presentation object that will receive the name of the file selected in the dialog.

n Fontboldobject, Fontitalicobject, Fontstriketrhoughobject, Fontunderlineobject. They all work with the Font dialog. When any of the related properties of a given font have been chosen in a Font dialog, a True or a False value is returned to the presentation object that is written into these properties.

n Fontnameobject, Fontsizeobject. They also work when the Font dialog is being used. The value returned to the presentation objects specified here is correspondingly the name of the font selected or the size of the font.

Exeblocks

This component is intended for storing code that will be reused in different points in a presentation. In this sense it acts as a functional library.

It can be inserted as if it were a visual component, being accepted by controls like Form, Panel, Scrollpanel, and so on. It can only contain the component Presentation.

n Syntax:

BEGIN Exeblocks Exeblocks1

BEGIN Presentation p1

94

Idpresentation = 0

.....

Any Action you want to include, Forms,...

....

END

END

When you want to invoke the code stored inside the presentation (p1 in the example above) you have to use an Action_call with the following syntax:

BEGIN Action_call Action_call1

Idpresentation = 0

Sentence = "*O*...ThePathOfExeblocks1/Exeblocks1.Call(p1)"

END



1. What is the virtual area? List two components that have this capability.

2. Which property is used for the multilingual feature? How can you test it?

3. What is the effect of setting the Modal property of a form to True?

4. What is the difference between the implicit flow control and the explicit flow control?

Review questions

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n The controls introduced in this lesson were: Tabstrip, Panel, Scrollpanel, Changers and Trees.

n Virtual area: a very handy feature to facilitate the design of some controls.

n Flow control: Action_goto, Onok, Oncancel, Onyes, and so on


Lesson summary

á Use the Changer and Tree controls to create fancy-looking presentations.

á Use the Action_goto component to control the flow of the program and introduce some logic to the presentation.

á Use the Action_dialog component to interact with the Open file, Save file, Color, Printers and Font dialog boxes.





Wizard does




Connecting to Meta4Objects

This is undoubtedly the most important chapter of the course together with chapter one. In this lesson you will learn to link your presentations to Meta4Objects. Up to now you have been working on forms, events, and visual controls. However you have not shown a single record stored in some table of the repository. This is where you will learn to load data into your presentations and show it to the user. Basically you will construct a bridge to your Meta4Objects.

Introduction

Lesson objectives


n Provide all the functionality implemented in a Meta4Object (or several) through a presentation.

n Implement navigation toolbars to navigate through the records of a given table.

n Execute Meta4Object methods from your presentations

n Create a Zoom List Group

n Use real advanced controls and properties to create highly functional presentations.

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Meta4Mind Menu Tree



100



Connecting to Meta4Objects 101

Linking components to Meta4Objects

An intrinsic and powerful aspect of the Frontend Designer is the easiness of connecting with data trough already designed Meta4Objects.

You should be very much aware of the fact that once you have connected your presentation with a Meta4Object the underlying Meta4Object structure will be as important as the design of the presentation itself. Thus be very careful and study the Meta4Object you will link to the presentation.

A great deal of the exceptional potential of Meta4Mind relies on the design of Meta4Objects, but care must be put on the underlying data model and on the presentation that finally brings the Meta4Object to the end user. Here you will learn the key points for building those interfaces, between Meta4Objects and end users, which are presentations.

Data properties

Every component in the designer tool has a set of Data Properties that link the component with a certain Meta4Object, a certain node or/and a certain item. Those properties are listed in the table below.

If none of the above properties is given a value, the component remains independent of any Meta4Object. Be aware of the fact that they require a sequential value assignment.

n Assigning a value to Idchannel means linking to a Meta4Object, independent of which node or item.

n Assigning a value to Idnode particularizes which Meta4Object’s node will be related to the presentation object.

n Finally, Iditem lets you link the object to a particular item of the Meta4Object.


Property name Meaning

Idchannel Identifier of the Meta4Object

Idnode Identifier of a certain node in the Meta4Object. It requires a non null value in Idchannel

Iditem Identifier of a certain item in a certain node of the Meta4Object. It requires non null values in Idchannel and Idnode

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Data properties are inherited through the Explorer Tree. Thus if you assign a value to the presentation’s data property it will be inherited in all the components contained by the presentation.

This inheritance can be broken by different ways that will be mentioned further on the course.

In order to gain experience on these concepts we suggest that you do the following exercise.

Exercise

a. Build up a presentation like the one in the figure below. Link the text boxes to the corresponding items in the STD_MT_COUNTRY Meta4Object.

b. Save your presentation and then preview it. Do you see any data on the linked items?

The answer to the above question is no. Why? The following sections explain why.

Loading options

Linking components is just the beginning of the process. As you might have guessed data have got to be loaded, and the loading processes have to be included inside the presentation.



Data is loaded using the Action_preload control.

n Action_preload: Syntax:

BEGIN Action_preload MyPreload1

Idchannel = "MyChannel"

Idnode = "MyNode"1

END

If the Meta4Object we are going to load has any kind of data filtering before the data is effectively loaded (i.e. any kind of filter defined at the root node level) or a track Meta4Object has been linked through a list connector, then a certain process of pre-loading takes place. This processes are invoked in the Frontend Designer by a property of Action_preload called Availablesteps.

We will not get into the details here2 but these are the possible preload steps:

As it has just been mentioned the property that lets you decide which one of the above mentioned steps is going to be present when loading data is Availablesteps. You can control this steps by giving the corresponding mask number as a value of this property. Combining the bit mask invokes different steps that will take place in the sequence indicated in the previous table (e.g. Availablesteps = 12 shows first a filter for the Meta4Object and then the Ask Parameters dialog box).

n Availablesteps: Syntax

BEGIN Action_preload MyPreload1Idchannel = "MyChannel"Idnode = "MyNodeNotMandatory"Availablesteps = XX

END

1. This is optional

2. For further explanations see the section devoted to tracks

Preload step Mask number Binary code

Choose list dialog 1 00001

Filter list dialog 2 00010

Filter channel dialog 4 00100

Ask parameters dialog 8 01000

Display list dialog 16 10000

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In order to practice the concepts introduced in this section we suggest that you do the following exercise:

Exercise

a. Insert an Action_preload in your presentation.

b. Save and run now your presentation.

c. Change the sequence in the execution order so that Action_preload takes place before Form1. You can do this either directly changing the OBL code or through the Properties dialog box changing the Execorder property of the controls3.

d. Save and preview your presentation.

You will learn more about Action_preload taking control of the underlying Meta4Object structure. Specially if tracks or dynamic filters are present.

Controls closely related to Meta4Objects

Getting into the details of DMD and Meta4Object design is out of the scope for this course. However you will need to work with a data model and a Meta4Object in order to understand the behavior and functionality of some the controls of the Frontend Designer. The data model and Meta4Object you will be working with are depicted below in the following figures.

3. Be aware!. Changing Execorder will not change the order of the nodes in the Explorer, but it has the desired effect in run time. Furthermore, after reloading the presentation the Explorer tree is synchronized to the Execorder property.

Figure 57. Changing the order of execution


In the data model above, two single-node Meta4Objects have been generated for every table, the Track and Maintenance Meta4Objects. In addition a multi-node Meta4Object was constructed using the Meta4Object Designer Tool. Its structure is shown in the figure below.

Figure 58. Data model

Figure 59. CMP_M4O_COSTS Meta4Object

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Node structures have been inherited from the corresponding MT Meta4Objects. Nor a track neither any kind of filter has been connected to this Meta4Object.

Briefly, this Meta4Object is intended for creating courses indicating a number of characteristics and assigning different costs to courses.

Let’s build up a presentation for this Meta4Object. Please follow the steps in order to successfully complete the exercise.

Exercise

a. Click the New Presentation button on the window toolbar.

b. Create 10 text boxes and 10 labels as shown in the figure below. TIP: Use the copy & paste option.

c. Set the Text property of the boxes to "" and the Alignment property of the labels to 1.

d. Add an Action_preload and correct the execution order so it takes place before Fom1.

e. In the Presentation’s Property dialog box link the presentation to the Meta4Object named CMP_M4O_COSTS. Set the following properties:

n Idchannel = CMP_M4O_COSTS

n Idnode = ROOT

f. Now link each textbox with the corresponding Meta4Object item. The following table will help you.

Figure 60. Presentation design


g. Save your presentation an preview it. You should see the following screen.

Control Iditem

Textbox1 ID_COURSE

Textbox2 DT_START

Textbox3 DT_END

Textbox4 N_COURSE

Textbox5 ID_PAY_TYPE

Textbox6 CMP_DD_BB

Textbox7 CMP_EX_KN

Textbox8 CMP_LANGUAGES

Textbox9 CMP_HH_RR

Textbox10 CMP_PREVIOUS

Figure 61. Presentation preview

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Text property. Multi language options. Hard coded text vs. data bound text.

Obviously a label saying ’Label1’ results meaningless in a final screen. The text property of each label should be changed.

To which value? You have already changed the text property and used the possibility of multi language values. Connecting to Meta4Objects enlarges this multi language facility.

Meta Data accepts being translated into different languages, that is the translated values are stored in the data base. There is a way to use the value of a meta data and leave it variable so when connecting in one language or another the presentation will display the value in the corresponding language.

The following table reflects the way to refer to the value of a certain meta data in the presentation.

For instance, setting the Text property of Label1 as:

Text = ##TM[ID_COURSE]

will assign the corresponding Item name value to the label.

Do the following exercise:

Exercise

a. Change the text property of all the labels to the following values:

Meta4Object name ##CHNNL[Meta4Object´s ID]

Node name ##ND[Node´s ID]

Item name ##TM[Item ID]

Control Text

Label1 ##TM[ID_COURSE]

Label2 ##TM[DT_START]

Label3 ##TM[DT_END]

Label4 ##TM[N_COURSE]

Label5 ##TM[ID_PAY_TYPE]

Label6 ##TM[CMP_DD_BB]

Label7 ##TM[CMP_EX_KN]

Label8 ##TM[CMP_LANGUAGES]


b. Save your presentation. You can see in the design how labels have taken the corresponding value of the data name.

c. Change the language from English to Spanish in the status bar, as you did in previous lessons. Notice how the labels change their text from english to spanish.

The great advantage of this value assignment is obvious, you no longer need to insert language options in a ’hard coded’ way. This sort of soft coded value assignment will do it for you!.

Notice the big difference between this ’multi language’ option and the one used in Lesson 4. You deal here with data base data. The name of a menu option is not data base data, and therefore you need the method used in Lesson 4.

Toolbar navigation buttons. First approach.

Your simple Meta4Object has been loaded and the first record is to be seen on the screen. The next step is to be able to change the record.

This is commonly done by means of a toolbar button with a suitable action linked to it. The following table summarizes the images and actions that typically implement this functionality. Of course the value given to the Image property is meaningless for this purpose.

Label9 ##TM[CMP_HH_RR]

Label10 ##TM[CMP_PREVIOUS]

Image Action Meaning

First Moves to the first record of the block loaded in the node

Last Moves to the last record of the block loaded in the node

Next Moves to the next record of the block loaded in the node

Previous Moves to the previous record of the block loaded in the node

Control Text

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To practice, we suggest that you do the following exercise:

Exercise

a. Add a toolbar and the four navigation buttons. Assign them the corresponding actions. Tip: you can use the Duplicate option...

b. Save your presentation as: CXX_EXAMPLE_5_4_PARENT.

c. Preview your presentation.

d. Test the navigation buttons.

Multinode Meta4Objects.

The Meta4Object you are dealing with has a child node whose records are loaded when the root record is loaded4. You will now add the possibility of viewing the child node records.

You will do it in a different number of ways.

The easiest way is to devote a certain area of the present form to textboxes and labels linked to the child node. In order to organize your presentation you will insert parent related controls into a scrollpanel and child related controls in a second scrollpanel.

Please follow the steps:

Exercise

a. Save the CXX_EXAMPLE_5_4_PARENT presentation as CXX_EXAMPLE_5_5_CHILD1.

b. Add two scrollpanels to Form1. Place the controls related to the parent node in the top scrollpanel. Insert the necessary text boxes and labels for the child node into the second scrollpanel. The following tables will help you linking these new text boxes and labels to the corresponding items. BE AWARE of the Idnode property of each scrollpanel!

4. Nodes are connected in R-B mode and LOAD PRG methods are linked with Autoload = off

Control Iditem

Textbox11 DT_START

Textbox12 ID_COSTS

Textbox13 ID_COURSE

Textbox14 N_COSTS


c. Add the required navigation buttons to see child records in Scrollpanel2. The following figure depicts a preview of the presentation, if done correctly.

d. Save and preview your presentation.

Introducing the Record Insert Wizard

When building up presentations that connect with Meta4Objects without making use of the Default Frontend Wizard it turns out that most of the times what you want for your end user interface is more or less routinely designed.

Control Text

Label11 ##TM[DT_START]

Label12 ##TM[ID_COSTS]

Label13 ##TM[ID_COURSE]

Label14 ##TM[N_COSTS]

Figure 62. Presentation with scrollpanels

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Usually you will need a textbox for displaying a given item value, thus you will insert a textbox control, and set its text property to "".

Then you will chose the Meta4Object’s ID for the textbox Idchannel, a certain node for Idnode and the item’s ID for the Iditem property.

Most likely you will add a label, with its text property set to "##TM[ID_ITEM]", and Alignment = 1 so the text is right aligned.

It can happen that the item you want to include needs additional controls, as e.g. a date, where you will probably have to enable the date selection by means of the ways explained along the course.

All these steps are repeated each time a new item is added in a form. Time and effort are saved by the integration of the Default Frontend in the Frontend Designer.

Default Frontend integration enables the use of an extremely well programmed Wizard for inserting controls. You will choose which item from which Meta4Object you want to include in your design. According to the underlying data definition of the item this sub-wizard will perform all the steps to include the item’s related components you would expect to appear in a Default Frontend presentation. Here is a guided exercise to show this powerful utility.

In this exercise you will design a form that will display some fields included in the Meta4Object you are working with throughout this lesson. (CMP_M4O_COSTS). In particular you will insert controls for the following items:


Complete now the steps of the following guided exercise:

Figure 63. CMP_M4O_COSTS II

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a. Create a new presentation and right click Form1. A pop-up menu will appear.

b. Select the Record Insert Wizard option from the pop-up menu. This option starts the wizard.

c. Select the Meta4Object that contains the items for which you want to create controls in your presentation. This Meta4Object is CMP_M4O_COSTS

d. Select the DT_START item from CMP_ROOT_COURSES.


Action_value

n Action_value: Syntax

BEGIN Action_value MyActionValue1

Dialog = "PropertyValue"

Inputvalue = "ValueToAppearInTheDialog"

Outputvalue = "ItemToRecieveTheDialog’sValue"

END

This control displays a dialog showing a calendar, a calendar with a clock or a calculator. The specific kind of dialog is set through the Dialog property, which can have the following values:

e. The wizard finds out what kind of item is it going to deal with, i.e. whether it is a method, a column containing a date or a combo-like column... This information will lead to different constructions in terms of presentation objects (Calendar buttons, enabled or disabled textboxes, and so on...). When the wizard has found out what kind of controls would be used in a default presentation to show this item, a dialog listing those presentation objects is displayed. In your example the wizard displays the construction: Label + Textbox + Button.

f. Click the Next button.

Dialog property values Meaning

Dialog = "Date" Displays a calendar

Dialog = "Datetime" Displays a calendar and a clock

Dialog = "Numeric" Displays a calculator

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Parameters can be transferred from the presentation to the dialog and from the dialog to the presentation using the properties Inputvalue and Outputvalue. The first one transfers the parameter value from the presentation to the dialog. The second one has to be one item that, after clicking the dialog’s OK button, will receive the value chosen in the dialog.

This component also has the Onok and Oncancel properties.


Exercise

a. Add a calendar button to the presentation CXX_EXAMPLE_5_5_CHILD1 for the field containing dates. Use Action_value’s properties to enable the selection of the date in the dialog and pass its value to the field.

b. Save and preview your presentation.

Action_list

n Action_list: Syntax.

BEGIN Action_list MyActionList1

BEGIN Listcolumn Listcolumn1

Iditem = "ItemToBeListed1"

Text = "Colum1Title"

END

...............

BEGIN Listcolumn ListcolumnN

Iditem = "ItemToBeListedN"

Text = "ColumNTitle"

END

END

This control opens a List dialog. The columns are set by inserting Listcolumn controls and linking the Iditem data property to the items you want to be included in the column.

This component also has Onok and Oncancel properties.


Exercise

a. Add a button in CXX_EXAMPLE_5_5_CHILD1 presentation. Make it work as follows: when clicking on the button a List dialog with DT_START and ID_COURSE fields must be displayed.


Patternbox

n Patternbox: Syntax.

BEGIN Patternbox MyPattern

Pattern = "[#Meta4ObjectItem1] Any Character... [#Meta4ObjectItemN]"

END

This control displays in run time the value of the Meta4Object element(s) that are given in the property Pattern.

Specific patterns will be discussed in later sections. References to pattern objects usually begin with the string *D*, but this string is not mandatory.


Exercise

a. Add a patternbox in CXX_EXAMPLE_5_5_CHILD1 presentation showing the Meta4Object’s name (#Idchannel).


Nodestatus

n Nodestatus: Syntax

BEGIN Nodestatus MyNodestatus


Idnode = "MyNode"

END

This component appears as an icon in the presentation. In run time it represents graphically the status of the current record in the node it is linked to.

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The following table shows the meaning of the different icons.

Table

Here you will be presented a control designed to allow a massive view of the records in a block, the so called Table control.

n Table: Syntax.

BEGIN Table MyTable

Insert the components to be seen inside the table (Column, Textbox,...)

END

Suppose that you want to implement a presentation like the one done before but instead of navigating in a sequential way, you want the whole child block to be displayed as a table. Please follow the steps to achieve that functionality:

Exercise

a. Open the CXX_EXAMPLE_5_4 _PARENT presentation and save it as CXX_EXAMPLE_5_6_CHILD2.

b. Insert a scrollpanel for the parent-linked objects and a second scrollpanel for the child objects (this second scrollpanel is empty in this moment). The following figure shows the Explorer Tree and the form at this step. Remember to link Scrollpanel2 to the child node.

Icon Meaning

Record loaded in the node

New record in the node

Modified record in the node

Deleted record in the node


a. Insert a Table control in Scrollpanel2.

b. Set the Align property of Table1 to All.

c. The child node has four fields. Add a textbox for each field and link it with the corresponding Meta4Object item.

d. Save and preview your presentation. The following figure shows this presentation in design time. The Scrollpanel1s are not expanded in the tree for space reasons.

Figure 64. Presentation with a table control I

Figure 65. Presentation with a table control II

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Further steps on data related Actions and Toolbarbuttons

A number of actions have been programmed in order to implement the possibility of working with records from a presentation. The following table lists some of them along with the usual image associated.

To practice, do the following exercise:

Exercise

a. Open the CXX_EXAMPLE_5_6 _CHILD2 presentation.

b. Add a toolbarbutton in Scrollpanel1 for inserting new records and another for saving changes.

c. Save and test your presentation.

d. Insert a new record.

Image Action Meaning

Removefilters Removes the active RAM filter if any

Delete Deletes the present record

Undo Undoes the last action

Copy Copies to the clipboard

New Generates a new record

Paste Pastes from the clipboard

Reload Reloads

Save Saves

Find Open the ’Find’ dialog box

Filters Shows active RAM filters

Cut Cuts and copies the contents in the clipboard


Toolbar groups

Instead of adding each button an the related action the Designer Tool offers several Toolbars that group buttons with actions already programmed. This simplifies the presentation design at the cost of having less control and flexibility over the behavior of the mentioned Toolbars. Table 5.X shows the available Toolbar groups.

To practice, do the following exercise:

Exercise

a. Add a Toolbar and a Datagroup to the CXX_EXAMPLE_5_6_CHILD2. You must add this Toolbar inside Scrollpanel2. Thus, make the corresponding changes in the Height property of Table1.

b. Save and test your presentation.

c. Add new child records to the new parent record created in a previous. Save changes.

Image Name Meaning

Datagroup New, Delete, Undo, List, Show/Remove Filter, Find

Editgroup Cut, Copy and Paste

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The figure above shows the presentation in runtime.

Advanced data related Actions - Use of Action_call - Action_dataprops

You can always implement a certain functionality in a Toolbarbutton by invoking a certain method through an Action_call action. Here is an example.

n Action_call. Example. Printing a form.

BEGIN Toolbarbutton MyPrintButton

Image = "#Print"

BEGIN Evclick EvClick1

BEGIN Action_call Print

Sentence = "*O*/MyFormReference.Print"

END

END

END

Figure 66. Presentation with a table control: preview


There is also an action provided by the Frontend Designer that enables the execution of a great deal of actions and includes properties that add certain logic to the process that will take place when the action is executed. This control is called Action_dataprops.

n Action_dataprops: Syntax.

BEGIN Action_dataprops MyDataprops

…. (Specific properties)

END

Useful properties of Action_datprops are listed in the following table.

Example. Adding a Toolbarbutton that reloads the Meta4Object:

BEGIN Toolbarbutton MyToolBarButton

Image = "#Reload"

BEGIN Evclick Evclick1


Reload = True

END

END

END

Example. Executing a certain method defined in the Meta4Object:


Property Meaning

Action Name of the specific action to be executed

Actionifinvalidpos Name of the action to be executed in case position is not valid

Actionifvalidpos Name of the action to be executed in case positions is valid

Load When set to TRUE it loads the Meta4Object. On False it does not load the Meta4Object

Reload When set to TRUE it reloads the Meta4Object. On False it does not reload the Meta4Object

Unload When set to TRUE it unloads the Meta4Object. On False it does not unload the Meta4Object

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he


Idnode = "MyNodel"

Iditem = "MyItemMETHODl"

Action = Execute

END

Action_method

In case you want to execute a method defined in a Meta4Object the component Action_method enables its execution5.

Action_method has a number of properties that enable a bi-directional dialog between the Presentation and the Meta4Object. Here is an example that will show you how to send values from a presentation to the method, and how to collect a value returned by the method (if any) in the presentation.

In this example we will work over the XMP_METHODS Meta4Object where a record-scope method has been defined with two varstring-type arguments. The method is depicted in the following figure:

This method will concatenate the string in XMP_ARG_1_METH_1 with the string in XMP_ARG_2_METH_1 and return the concatenated string.

What we will do in this example is design a presentation where the value of XMP_ARG_1_METH_1 and XMP_ARG_2_METH_1 is established by the end user in run time. Then the execution of the method will be triggered through an Action_method, and the returned string will be shown in a textbox.

The design of the presentation is shown in the following figure:

5. Executing a method in a given Meta4Object can also be achieved with Action_dataprops. The property Action can get the values ’Execute’ and ’Executewithoutparameters’. This triggers the execution of the method specified in tIditem property of Action_dataprops.

Figure 67. Rule


Notice that Action_method has been inserted into Evclick1. To enable the execution of the XMP_METH_1_1 method, the data properties of Action_method have to be set to:

The property Sourceargs is where you must specify the identifier of the method arguments in the Meta4Object, separated by commas. Thus:

The presentation will assign a value to those arguments, and the property Sourceobjs is where you establish which presentation object is the one containing the value you want to assign to each argument. In our example:

Notice that they have to obey the same sequence than Sourceargs, and they are also separated by commas. In a certain way, these properties enable the dialog between the presentation and the Meta4Object.

Figure 68. Presentation with Action_method

Idchannel XMP_METHODS

Idnode XMP_ROOT_METH

Iditem XMP_METH_1

Sourceargs XMP_ARG_1_METH_1,XMP_ARG_2_METH_1

Sourceobjs *O*.../Textbox1.Text,*O*.../Textbox2.Text

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Now where to write the result of the method execution has yet to be established. This is done through the Returnobj property. In our example:

The complete OBL code for the Action_method component would then be:

BEGIN Action_method Action_method1

Idchannel = "XMP_METHODS"

Idnode = "XMP_ROOT_METH"

Iditem = "XMP_METH_1_1"

Sourceargs = "XMP_ARG_1_METH_1,XMP_ARG_2_METH_1"

Sourceobjs = "*O*..../ Textbox1.Text,*O..../Textbox2.Text"

Returnobj = "*O*.../Form1/Textbox3.Text"

END

Action_bp

Any task designed with the Task Designer tool can be invoked from a presentation through the component Action_bp. All you need is the Task Identifier. This must be the value of the Idbp property of the Action_bp.

This is the complete syntax:

BEGIN Action_bp Action_bp1

Figure 69. Source objects and source arguments

Returnobj *O*.../Textbox3.Text

Presentation

Textbox1.Text

Textbox2.Text

Method

XMP_ARG_1_METH_1

XMP_ARG_2_METH_1

SourceobjsSourceargs


Idpb = "IdentifierOfTheTaskYouWantToExecute"

END

Using Split controls

Just to add a certain amount of ergonomy to the presentation you have just designed, you will now insert the parent-related scrollpanel in the upper block of a splittvertical control, and the child-related scrollpanel in the lower block. The following figure illustrates the idea.

Save this presentation as CXX_EXAMPLE_5_7_CHILD3.

Mimic control

In the CXX_EXAMPLE_5_5_CHILD1 presentation you displayed child records as a form, i.e., in a sequential way. In the CXX_EXAMPLE_5_6_CHILD2 you used a table control to show massively the same information.

It is a common requirement to enable the end user to choose between those to view of displaying information in run time. The designer tool introduces the Mimic control to enable this kind of functionality.

n Mimic: Syntax

BEGIN Mimic MyMimic1

....

Class = "InitialClassToBeEmulated"

...

END

Figure 70. Split controls

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The Mimic control acts as a class emulator. The class it emulates is defined through the Class property, which can take the values Scrollpanel to imitate a form, and Table to imitate a table.

It should be mentioned that a Mimic control does not emulate the methods of the above mentioned classes. In fact, this control supports only the Class method, which is enables you to change the mimic class in run time. The access to the Class method is achieved through the use of an Action_call component.

n Syntax

BEGIN Action_call ChangeMimicClass

Sentence = "*O*MyMimic1Path.Class(TheClassYouWantToChangeTo)"

END

Thus this change from ’Form’ to ’Table’ in run time requires:

a. To use a mimic control as a container for the node related objects.

b. To use an Action_call invoking the Class method.

You will learn how to use the mimic control through the following exercise. In this exercise you will enable a class change in the child node. Steps would be the same in case you wanted to add a mimic control in the parent block.

Exercise

a. Open the CXX_EXAMPLE_5_5_CHILD1 presentation and save it as CXX_EXAMPLE_5_7 _CHILD4.

b. Insert a Mimic control in Scrollpanel2 and place all the child objects (Label11 to Label14, Textbox11 to Textbox14 and the navigation buttons) in it.

c. Open the mimic’s OBL code and add the following line:

Class = "Scrollpanel"

d. Save and test your presentation.

e. Add two buttons to Scrollpanel2 with the following functionality:

n When Form1 is displayed in run time the button Form must be disabled6.

6. The property Class of the mimic control has been set to ’Scrollpanel’, thus it resultsmeaningless to allow the user to ’change’ again to the same class.


n When clicking the button Table, the mimic class must change to Table, the button Form must be enabled and the button Table must be disabled.

n When clicking on the button Form, the mimic class must change to Scrollpanel, the button Form must be disabled and the button Table must be enabled.

5.2.17 Back to changers

You have already dealt with changers in lesson 4. The next exercise will show you how to use a changer when multinode Meta4Objects are at play.

Changers (lesson 4) established different visual levels. The idea is to use one level of the changer to display the parent node’s data and another level for the child node.

Exercise

a. Open the CXX_EXAMPLE_5_4_PARENT presentation and save it as CXX_EXAMPLE_5_8 _CHILD5.

b. Insert a changer in Form1 and insert all the controls shown in the figure below inside a Tabstrip. Tip: Use the OBL editor and the copy & paste technique. Adjust the sizes of the controls when necessary.

Figure 71. Presentation with a mimic control

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c. Add a second Tabstrip control to the changer, and insert labels and text boxes to be linked to the child node items.

d. BE AWARE OF THE CORRECT VALUE OF PROPERTY Idnode FOR YOU WANT TO INSERT CONTROLS LINKED TO THE CHILD’S NODE INTO Tab1 of Tabstrip2.

e. Insert a Splitthorizontal control in Form1 and again insert the changer inside Splittblock2 (Tip: Use the OBL editor and the copy & paste technique). Add a Tree to Splittblock1 and implement the corresponding nodes, events and actions so that changes in the changer are controlled through the tree.

f. Add the necessary navigation buttons in Tab1 of Tabstrip2 in order to enable the navigation through the child node.

Action_script, Checkbox and Checkboxgroup

Action_script

You can execute LN4 code typed in the presentation using Action_script.

n Action_script: Syntax.

BEGIN Action_script MyLN4Script


Idnode = "MyNode"

Figure 72. Presentation with a changer


Sourcenames = "MyLN4Variable1,...MyLN4VariableN"

Sourceojbects = "[ValueForMyLN4Variable1],...[ValueForMyLN4VariableN]"

Code = "LN4Code(MyLN4Variable1,...MyLN4VariableN)"

END

This action has Onfalse and Ontrue properties that can be used as conditionals.

The LN4 code is neither checked nor executed inside the presentation. In fact, to execute LN4 code, a Meta4Object node has to be assigned in the Action_script data properties thus Idchannel and Idnode become mandatory7.

Exercise

a. Open the CXX_EXAMPLE_5_4_PARENT presentation and save it as CXX_EXAMPLE_5_4_SCRIPT.

b. Build the following functionality:

n When the value of the field in Textbox7 (linked to CMP_EX_KN) is validated two cases are distinguished:

n Case 1: the value is "1". Then a message box saying "Value is 1" appears.

n Case 2: the value is not "1". Then a message box saying "Not 1 value" appears.

HINTS: use the following LN4 code:

Code = "if EK="1" then return(1) else return(0)"

c. Where EK is the name of a LN4 variable.

Checkbox control

n Checkbox control: Syntax.

BEGIN Checkbox MyCheckbox

Truevalue = ""

Falsevalue = ""

Value = ""

END

7. We shall make use of the system method called ExecuteLN4JIT.

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Truevalue, Falsevalue and Value properties are not mandatory. Checkboxes can behave in different ways depending on whether or not this properties are being used.

Value = 0 means unchecked and Value = 1 means checked.

It can contain the Evvalidate event, triggered when checking and unchecking the checkbox.

Exercise

a. Open the CXX_EXAMPLE_5_4_SCRIPT presentation and save it as CXX_EXAMPLE_5_4_CHECK.

b. Add a checkbox with the following functionality:

n When the checkbox is checked a messagebox saying "I am checked" will appear.

n When unchecked, the message "Not checked now" will be displayed.

If a checkbox is linked to a Meta4Object item, Truevalue and Falsevalue properties can be used in order to choose between these two values, which will be transferred to the Item.

BEGIN Checkbox MyCheckbox


Idnode = "MyNode"

Iditem = "MyItem"

Truevalue = "True"

Falsevalue ="False"

END

When a checkbox has been linked to an item and Truevalue and Falsevalue have been assigned a non null value (True and False in our example) the following processes take place:

n When reading a record: if the value of MyItem is equal to True, the checkbox appears checked. If it is equal to False it will be unchecked.

n When writing in a record (either new or being modified) checking the checkbox assigns the value True to MyItem. Leaving the checkbox unchecked assigns the value False to MyItem.


Exercise

a. Add a groupbox control and reorganize the labels and textboxes as in the following figure. Add checkboxes where indicated by the figure.

b. The check boxes in Groupbox1 must reflect whether the related Extended Knowledge is required or not. The Needed Extended Knowledge Checkbox must enable/disable Groupbox1.

c. Add also a New button for the insertion of new records.

d. Save and test the presentation.

Listgroup

In a number of cases the data model underlying a Meta4Object that is loaded in a presentation shows relations between the tables it contains. This is the case of the data model we have used, where table CMP_PAY_TYPES is related to table CMP_TB_COURSES through the element ID_PAY_TYPE.

You have learned in previous courses that in such cases the table CMP_PAY_TYPES can act as an auxiliary table for the table

Figure 73. Presentation with a groupbox

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CMP_TB_COURSES. Generally a single-node Meta4Object is created for each auxiliary table with the help of the Data Model Designer Wizard8.

In such cases it turns out to be extremely useful to reflect such relations into the presentation enabling a number of operations that exploit the fact that an auxiliary table has been included in the data model.

It is the aim of this section to show you how to implement a List/Validate group (ZLG) in your presentation. You do this with the Listgroup control.

The basic functional schema of what you shall implement in the presentation is shown in the following figure.

Bear in mind that the final goal of an auxiliary table is to:

n confront the values given to a certain table item with the values already contained in a second table (the auxiliary table), which includes validating those values and/or listing the records of the second table.

n enable the insertion of new records in the auxiliary table.

n enable a fast zoom to the record in the auxiliary table.

Notice that a ZLG requires working with three different Meta4Objects:

n The multinode Meta4Object (in our example CMP_M4O_COSTS).

n The List/Validate Meta4Object created for the table CMP_PAY_TYPES9.

8. Remember the steps followed when generating the single-node Meta4Objects.

Figure 74. Elements of the Zoom List Group

9. Both the Track and Maintenance Meta4Objects were created using the DMD Wizard.

Label TextboxW TextboxL1 TextboxLN...

Evclick to the maintenanceMeta4Object presentation

• Evdbclick to the trackMeta4Object presentation

• Evvalidate validating theTextboxW.Text value

Evdbclick validating theTextboxLi.Text valueagainst the table.

Evclick to the trackM4Object presentation


n The maintenance Meta4Object created for the table CMP_PAY_TYPES.

A number of specific methods (List, Validate, Zoom...) that implement the functionality described are programmed by the DMD Meta4Object Wizard as methods of the Track and Maintenance Meta4Objects. You will learn how to invoke those methods in order to build a ZLG. Notice that the methods List and Validate are included in the Track Meta4Object while the Zoom method is included in the Maintenance Meta4Object.

A ZLG also implies rising the presentations of the track or maintenance Meta4Objects depending on the case. And, above all, it implies a certain information flow. In this last sense you will deal with an origin and a destination of information.

The Listgroup control will help you in creating this sort of functionality. It is by far one of the most complicated controls in the designer tool and a deep understanding is out of our present reach. Here you will be given some basic hints in order to be able to create a ZLG disregarding the Frontend Designer’s wizard.


a. Open the presentation CXX_EXAMPLE_5_8 _CHILD5 and save it as CMP_EXAMPLE_LVG.

Figure 75. Track and Maintenance Meta4Objects

136

b. Notice that tables CMP_PAY_TYPES and CMP_TB_COURSES are connected through the column ID_PAY_TYPE. This column is represented by the field item ID_PAY_TYPE in the Meta4Object we are dealing with (CMP_M40_COSTS).

c. Thus the ZLG must be constructed as:

d. Add the necessary changes to get the visual design shown in the figure above. Use Image = #List for the list button.

e. Add the necessary events in each control. The following table will help you.

f. Save your presentation.

Structure of the Listgroup control - The Function control

You have just prepared the visual components of the ZLG. Now you will learn where to give the parameters for enabling the ZLG functionality by means of the Listgroup control.

This control will act as the bridge between the already mentioned Meta4Objects. Parameters for this ’communication’ are passed through a number of properties.

n Listgroup: Syntax

BEGIN Listgroup MyListgroup

Idchannel = "Meta4ObjectOrigin"

Figure 76. The Zoom List Group

Presentation object Events to be inserted

Evclick

EvdbclickEvvalidate

Evdbclick

Evclick


er

in

sary

of

Idnode = "NodeOrigin"

Iditem = "ItemOrigin"

Watchobject = "PresentationObjec.BooleanProperty"

BEGIN Function MyFunction1

….

END

BEGIN Function MyFunction2

….

END

…

END

g. Insert a Listgroup control in Tab1 of Tabstrip1.

The Listgroup control includes a first block of data properties (data headin the OBL code listed above). This block must identify the item aroundwhich the ZLG is going to be built. In our example ID_PAY_TYPE.

Listgroup properties include one which plays a mayor role, the Watchobject. Remember we shall create a ZLG around a certain item (our example ID_PAY_TYPE). This item's value is to be seen through acertain presentation control, most typically a textbox like TextboxW in the figure, i.e. a certain presentation object is receiving the value of the itemacting as the keystone of the whole ZLG.

The whole TextboxW.Visible construction is called the Watchobject. When the Visible property of the Watchobject is set to True validations are enabled.

Then a number of blocks are defined, each of them collecting the necesdata for implementing the Zoom, the List, the Validate and the Clear functionality. Each one of this blocks is an event-like component called Function. Thus you will distinguish:

n Function List

n Function Zoom

n Function Validate

n Function Clear

At least one Function component is mandatory inside a Listgroup.

Opening the property dialog of a Listgroup control will display a numbertabs that will help you systematize all the information required by the

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Listgroup control.

h. Open the property dialog of Listgroup1.

General properties of Listgroup

Data properties of the Listgroup control must reflect the fact that we are dealing with that special Meta4Object item (in our example ID_PAY_TYPE), thus they must be assigned a non null value that particularizes up to the item itself.

i. Inside the dialog of Listgroup1, set the data properties to their corresponding value. The following figure will help you.

j. Write the path reference of the Watchobject in the corresponding textbox. Remember to give the reference and the property whose boolean value will enable or disable validations.

*O*../Textbox5.Visible

Figure 77. General Properties of the Listgroup control


In this General tab the three Meta4Objects you will deal with have to be identified. The central one is already included in the General Props frame.

The second frame will collect data about the Meta4Object invoked for the List and Validate methods.

The third frame copes with the Meta4Object containing the Zoom method.

k. Identify each Meta4Object.

l. Give the required parameters for the List Meta4Object and the Zoom Meta4Object frames.

Function properties

Up to now you have just begun with the basic aspects of a ZLG construction. To get on with the following steps giving a thought on what you are doing with all this Meta4Objects and methods becomes necessary.

The following discussion will be focused on the Validate Function for. At the end of this section the other Function blocks will be explained.

Refer to the figure above when needed. The Alias is written belowbelow each control for guidance. The following figure shows the records in the Track Meta4Object, i.e. the records of table CMP_PAY_TYPES.

Passing data Part I - Mainargs and Mainobjs

n What happens when a new value is written in Textbox5?. It was stated above that when loosing focus the Evvalidate comes into stage triggering the following process:

Figure 78. Zoom List Group II

Figure 79. Records in the Track Meta4Object

Label5 Textbox5 Textbox15 Button1

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d:

t to e is

. To

1. What is written inside Textbox5 must be validated against the table of the Track Meta4Object.

2. In case validation is correct then the Track Meta4Object must send back the value to be displayed in Textbox15.

3. For simplicity the ’not validate’ case will be discussed later on.

n In terms of presentations and Meta4Object:

1. you have to pass the value of *D*ID_PAY_TYPE (what is written in Textbox5) to the track Meta4Object.

2. the track Meta4Object must receive the *D*ID_PAY_TYPE value and run its Validate method.

This information flow has to be done using some argument of the track Meta4Object. Remember this track Meta4Object was generated by the DMD Wizard. This extremely well programmed tool defines the parameters needed in the List, Validate and Zoom methods as the column name preceded by the string ARG_ string. Thus, in your example, an argument called ARG_ID_PAY_TYPE has been defined by the DMD Wizard both in the Track and in the Maintenance Meta4Objects.

In a certain way what is needed here is a sort of ’assignment’ of the kin10

ARG_ID_PAY_TYPE=*D*ID_PAY_TYPE

Remember that, in this example, as we are dealing with TR and MT Meta4Objects generated by the DMD wizard the name of the argumenbe used by all the methods in TR and MT Meta4Objects we shall invokthe same.

Now the question is how to make the ARG_ID_PAY_TYPE=*D*ID_PAY_TYPE assignment. And here again, we can use the Listgroup dialog.

Click the Source Data button in the Listgroup General Props property dialog and write the corresponding data as stated in the following figureenable the insertion you must click the ’+’ symbol at the right border of theSource Data dialog.

10. WARNING: This is NOT to be understood in terms of a proper syntax use. This would be a completely invalid sentence.


Notice that this is a General Property of the Listgroup control, thus this assignment can be used by this control independent of which Meta4Object you want to pass *D*ID_PAY_TYPE to.

Passing data Part II - Targetitems and Targetobjs

Now, you have just enabled the passing of values between the origin Meta4Object (in your example CMP_M4O_COSTS2) and the TR and MT Meta4Objects. Lets go on with further steps.

m. The Track Meta4Object executes the Validate method. If the ARG_ID_PAY_TYPE is validated against table CMP_PAY_TYPE, the method returns the value of all fields in the record with the ’Position in list’ property different from zero. In your example the column N_PAY_TYPE has ’Position in List = 2’. So this has to travel back from the Track Meta4Object to the presentation where the Listgroup is included.

How do these values travel back to your presentation?. Generally speaking, what you need now is another ’assignment’ but this time the value sent by the track Meta4Object will be received by a presentation object. From now on, a so called Targetitem (the one coming from the Track) passes its value to a so called Targetobject (the presentation component where the Targetitem’s value is to be written).

This ’assignment’ has to be stated inside each Function tab.

You are dealing with the Validate Function in the example, so open the Validate function tab as shown in the figure below.

The value of N_PAY_TYPE for a given record has to be collected in the presentation.

Figure 80. Source data properties

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Which object in the presentation is the one receiving the value sent by the Validate method? Look at the figure above, Textbox15 (what is somewhere called a virtual field) is the object. Its property.Text is the one that can get the N_PAY_TYPE value. Thus, in terms of this ’assignment’ you would have something like:11

*O*/Presentation/Form1/Textbox15.Text = N_PAY_TYPE

This is what you state in the Validate tab. Just remember:

This would establish the parameters for the Validate Function block.

Here are some comments on the rest of the Function blocks defined in Listgroup control.

Figure 81. Validate Tab

11. AGAIN: This is not to be understood in terms of a proper syntax use. This would be a completely invalid sentence.

Targetobject Targetitem

*O*/Presentation/Form1/Textbox15.Text

N_PAY_TYPE


Function Zoom

This Function invokes the Zoom method in the Maintenance Meta4Object when clicking on Label1. It must display the Maintenance presentation built over the MT Meta4Object, but show only the record corresponding to the *D*ID_PAY_TYPE (passed by the Source Data assignment). No data returns from the MT Meta4Object thus, the Function Zoom tab would be as shown in the following figure.

Function Clear

In this case the text property of the virtual fields in the presentation have to be cleared, thus, in your example, you would have:

Figure 82. Zoom tab

Figure 83. Clear tab

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Function List

Function List has to be ready to receive the value of the columns of the record selected in the List Meta4Object’s presentation that have the property Position in List different from zero, included the one corresponding to the *D*ID_PAY_TYPE column.

In our example:

Now, the Listgroup control is ready to be invoked from the controls of our presentation.

Invoking the Functions in the Listgroup Control

Now you will finally implement the whole ZLG functionality.

Figure 84. Function list tab


To begin with, every control that will be used to invoke one of the Listgroup Functions has got to have the following property values:

n Idchannel = "MyChannel"

n Idnode = "MyNode"

n Iditem = Depends on the control

n Dependson = "*D*ThePresentationItem"

In our example:

n Idchannel = "CMP_M4O_COSTS2"

n Idnode = "COURSES"

n Iditem = Depends on the control

n Dependson = "*D*ID_PAY_TYPE"

We list the OBL code inside each control.

Label

You need the Function Zoom when clicking. Thus:

BEGIN Label Label5

Idchannel = "CMP_M40_COSTS2"

Idnode = "COURSES"

Dependson = "ID_PAY_TYPE"

Text = "##TM[ID_PAY_TYPE]"

BEGIN Evclick ToZoom

BEGIN Action_call CallZoom

Sentence = "*O*../../../Listgroup1.Zoom"

END

END

END

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Textbox (non virtual fields)

Refer to the figure that shows you the structure of the CMP_M40_COST2 to remind yourself of the functionality you want to build from this object. Double click must trigger the List Function, and Evvalidate the Function Zoom.

BEGIN Textbox Textbox5


Idnode = "COURSES"

Iditem = "ID_PAY_TYPE"


Collabel = "##TM[ID_PAY_TYPE]"

BEGIN Evvalidate ToValidate

BEGIN Action_call ToValidate

Sentence = "*O*../../../Listgroup1.Validate"

END

END

BEGIN Evdblclick ToList

BEGIN Action_call ToList

Sentence = "*O*../../../Listgroup1.List"

END

END

END

Textbox (virtual fields)

When double clicking it call the Validate Function.

BEGIN Textbox Textbox15


Idnode = "COURSES"

Editable = False


BEGIN Evdblclick ToValidate2


BEGIN Action_call ToValidate2

Sentence = "*O*../../../Listgroup1.Validate"

END

END

END

List button

You will invoke the List Function:

BEGIN Button Button1


Idnode = "COURSES"

Iditem = "ID_PAY_TYPE"

Image = "#List"

BEGIN Evclick ToList2

BEGIN Action_call ToList2

Sentence = "*O*../../../Listgroup1.List"

END

END

END

Advanced properties of the ZLG

By default, the presentations raised for the Track and Maintenance Meta4Objects are:

Track Meta4Object

n Its presentation is generated in run time so you don’t need to create a presentation for this Meta4Object.

n If you need to raise a specific presentation built for this Meta4Object you can change this default behavior by specifying the presentations ID in the Function List tab. See the figure below.

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Maintenance Meta4Object

n The presentation has to be available for this time it is not generated in run time. By default, the default maintenance presentation is invoked, i.e. the one with a name as the single-node Meta4Object plus the ’_MT_’ string. In our example that would be CMP_MT_PAY_TYPES.

n If you want to invoke another presentation instead of the default one you can change the Idinstance in the Zoom Function tab.

To understand the flow of these two functions the OBL code for Function List is listed in the following figure. See that inside the Function block a Presentation Meta4Object control is inserted.

Figure 85. Idinstance in the Function List tab

Figure 86. Idinstance in the Function Zoom tab

Idinstance = “TheListPresentationToBeRaised”

Idinstance = “TheMaintenacePresentationToBeRaised”


This in turn contains an Extends, whose Idinstance is #Default_list, i.e. the presentation will be created in run time. Changing the value of Idinstance here or in the Function List tab is equivalent.

The Presentation Preload block parameters can also be changed in the OBL editor or in the Function List tab.

The Inheritdata property has to be set to 1 in order to allow the sharing of data between the initial Meta4Object and the Track (or Maintenance) Meta4Object.

Notice that the parameters given in the General Props tab identifying the related Track Meta4Object are referred here as Idfuncchannel, Idfuncnode and Idfuncmethod enabling an easy identification of the information related to the initial Meta4Object or to the rest of the Meta4Objects.

In case the item is part of a foreign key the parent and son listgroups can be linked through the properties (General Props Tab) ParentListGroup and SonListGroup. Several parents can be included separated by commas.

If ParentListGroup has a non null value, after invoking the list method from the son the Validate method of the parent is invoked.

If SonListGroup has a non null value, deleting the value of the item in the

Figure 87. OBL code for Function List

BEGIN Function ListIdfuncchannel = "CMP_TR_PAY_TYPES2"Idfuncnode = "CMP_TR_PAY_TYPES2"Idfuncmethod = "LIST"Mainobjs = "ID_PAY_TYPE"Mainargs = "ARG_ID_PAY_TYPE"Targetobjs = "ID_PAY_TYPE,*O*/Presentation/Form1/Textbox15.Text" Targetitems ="ID_PAY_TYPE,N_PAY_TYPE" BEGIN Presentation Preload BEGIN Action_preload Default1 Onok = "END_OK" Oncancel = "UnloadForm" Availablesteps = 12 Loadchannel = False Actionnew = False END END BEGIN Presentation MetaObject BEGIN Extends Default2 Idchannel = "CMP_TR_PAY_TYPES2" Inheritdata = 1 Idinstance = "#Default_list" END END

END

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parent calls the Clear function of the son.

When foreign keys are around the Mainargs/Mainobjs assignment can be not enough for our Function. Properties Sourceargs and Sourceobjs enables further assignments in the block.

Finally we will mention the way in which internal flow takes place when invoking Listgroup functions.

n List flow:

1. Presentation Preload is executed

2. List Meta4Object is created

3. The List method in track Meta4Object is executed

4. In case no data are to be shown in the List node an error message appears and the flow dies away.

5. If only one record is loaded in the List node then its value is copied to the initial Meta4Object.

6. Presentation Meta4Object is executed.

7. If click on Cancel Function Clear is invoked and the flow dies away.

8. Copy values in List node to the initial Meta4Object.

9. End of the flow.

n Validate flow:

1. Validate Meta4Object is created.

2. The validate method is executed.

3. If there is no data on the Validate node List is invoked.

4. If there is more than one record in the Validate node List is invoked.

5. If there is only one valid record values in the Validate Meta4Object are copied to the initial Meta4Object.

The Record Insert Wizard and the ZLG

When running the Record Insert Wizard over data that contain relations in the dictionary with other tables there is the possibility of generating the whole ZLG. This means all the visual components plus the Listgroup control.

Moreover if the generated ZLG is a candidate for having a parent ZLG the wizard will prompt an option to construct both ZLG’s at the same time. This will be shown through an example.


a. Open a new presentation and activate the Record Insert Wizard.

b. Select the STD_MT_SUB_GEO_DIV Meta4Object and when its items are listed, select the STD_ID_GEO_DIV item. The figure below shows the relations that will be encountered by the wizard over the data contained in the Meta4Object.

c. Notice the relation established though STD_ID_GEO_DIV. This would mean a ZLG in a Default FrontEnd presentation. This is exactly what the Record Insert Wizard suggests as you can see in the right side in the figure below.

d. In case you want to ignore the ZLG generation possibility just click on the ’Other Components’ option button. A label and a textbox will be used.

e. If the ZLG is to be generated, the wizard will look for further relations in the dictionary. In the figure above a second relation is present. That would mean two ZLG in a default presentation. One for

Figure 88. Data Model II

Figure 89. Using the Record Insert Wizard to generate a ZLG

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STD_ID_GEO_DIV and another one for STD_ID_COUNTRY. The wizard brings this option by displaying the dialog shown in the next figure. Clicking in the STD_ID_COUNTRY option will lead to the hierarchical generation of both ZLGs.

f. Finally the figure below shows the result of the whole process.

Figure 90. Using the Record Insert Wizard to generate a ZLG II

Figure 91. Final result


Working with tracks

For optimization reasons in many cases a track Meta4Object is connected to the Meta4Object we want to work with12. Remember this is done by means of a List connection between the two Meta4Objects.

To see how a track connection is implemented through the Designer Tool you will work with a Meta4Object built from the Meta4Object you have been working with, but linked to a track Meta4Object. The track Meta4Object is normally created with the Data Model Designer wizard. .

In the example used below, the list connector is of a 1:N type and only one field of the PK has been used. This has been done for learning reasons.

Exercise

Lets build a presentation for a Meta4Object based on CMP_EXAMPLE_TRACKS_0.

a. Open presentation CMP_EXAMPLE_TRACKS_0 and save it as CXX_EXAMPLE_TRACKS_1. The presentation is shown below. Where Scrollpanel1 contains textboxes linked to the parent node of CMP_M40_COSTS3 Meta4Object, and Scrollpanel2 the ones linked to the same Meta4Object’s child node.

12. Why a track and how the connection is established is far beyond our present scope. Refer to the advanced aspects of Meta4Object design.

Figure 92. CXX_EXAMPLE_TRACKS_0 presentation

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If you test this presentation a QB form will appear, followed by a List form, both being related to the QB node and List node of the Track Meta4Object. Finally after choosing one record from the Track List you will see Form1 with the data corresponding to the first record loaded in the parent node of CMP_M4O_COSTS3.

No navigation buttons have been included in CXX_EXAMPLE_TRACKS_1 presentation.

a. Add a Navigationgroup in Scrollpanel1 and another in Scrollpanel2. Save your presentation.

Figure 93. Source Meta4Object

Figure 94. The corresponmding track and its structure.


Figure 95. List connector

Figure 96. Track

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Now, in order to understand what is happening in terms of records and nodes, take a look at the schema in the next figure.

Figure 97. Initial Meta4Object

Figure 98. Maintenance Meta4Object


b. Test your presentation following the steps of the figure above. Notice that when selecting in the List form the second record all records in the with the same DT_START value are loaded in the Root node.

Toolbar Navigation Groups

When list connectors are defined as 1:N it becomes important to enable the end user to navigate through the List node. Some specific controls have been included in the Designer Tool to facilitate navigation. The following tables display their main features.


List connector(by DT_START)

ROOT NODE

CMP_M4O_COSTS3

CHILD NODE

TRACK

QB NODE

TR NODE

STEP 1.- QB form

STEP 2.- List form

STEP 3.- list is 1:N by DT_START. Load in Root & Child

Image Type Meaning Classname

Navigation Group

Navigates through the related node

Toolbarnavigationgroup

NavRoot Group

Navigates through the parent node

Toolbarrootnavigationgroup

NavTrack Group

Navigates through the track node

Toolbartracknavigationgroup

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To get some practice, complete the following instructions:

a. Add the corresponding Navigation Groups to your presentation in order to be able to navigate through the Track. Use Scrollpanel3 for the Toolbartracknavigation control.

b. Save and test your presentation.

Specific patterns

Pattern objects become very useful when tracks are used, and as is the case with Navigation Groups, a number of specific pattern objects have been included to simplify your work. The following table includes some of them.

Image Action Meaning Classname

Firstdoc Moves to the first record loaded in the track node

Button

Lastdoc Moves to the last record loaded in the track node

Button

Nextdoc Moves to the next record loaded in the track node

Button

Previousdoc Moves to the previous record loaded in the track node

Button

Document #Docindex Number of present record

#Doccount Number of records in the node

#Docnodestr Shows the node’s items

Track node

#Trackindex Number of present record in the track node

#Trackcount Number of records in the track node

#Tracknodestr Shows track node´s items

Root node #Rootindex Number of present record in root node

#Rootcount Number of records in theroot node

#Rootnodestr Shows root node´s items

Current node

#Index Number of present record in current node

#Count Number of records in current node

#Nodestr Shows current node´s items


Here are some examples:

n Node counters:

BEGIN Patternbox MyPattern1

Pattern = "([#Index]/[#Count])"

Borderstyle = 0


Idnode = "MyNode"

END

n Node structures:

BEGIN Patternbox Mypattern2

Pattern = "[#Nodestr]"


Idnode = "MyNode"

END

Pattern objects also accept the scope modifier *T* at the beginning of the



Patternbox in run time

Index number ofcurrent register

Total numberof registersloaded in thenode

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pattern value (e.g. *T*#Count). The meaning of this modifier is to refer the object to the track node, if any.

In order to practice add counters and node structure controls to your presentation.

Steps in the preload

Remember that when the table over which you build a single-node Meta4Object is defined as non cacheable, Track Meta4Objects generated with the DMD Wizard have a QB Free node plus a List node.

In run time, if a Track has been connected to a certain Meta4Object you will get the sequence already described, i.e.

1. QB - step

2. LIST - step

3. Connection

4. Load in the Meta4Object

There are two more cases in which a certain step must be taken before the final Meta4Object is loaded:

a. dynamic filters defined in the Meta4Object

and / or

b. properties defined in the Meta4Object with node scope (parameters).

I n summary, there are four possible preload steps:

The Action_preload control lets you modify the number of steps that will take place in the Meta4Object preload process as was mentioned in previous sections. Remember this was attained through the property

Step Meaning Defined in...

QB Filter the list presented by the list node of the track

Track Meta4Object

LIST Lists records charged in the List node of the track

Track Meta4Object

Dynamic Filter Filters the records to be loaded in the Meta4Object

Source Meta4Object

Parameters Filters according to the value of a property defined with node scope.

Source Meta4Object


Availablesteps.

Now that you have learned how to take control over the display of different records in a node you will understand the potential of the Avaliablesteps property.


a. Edit the OBL code of Action_preload1. Add the line:

Availablesteps = 31

b. This will make no change in the preload for 31 means a ’11111’ mask, i.e. all available steps.

c. Save and test your presentation.

d. Change now Availablesteps to 3 (i.e. ’00011’ ). Save and test your presentation. Notice the following features:

n The list is not displayed.

n The first record in the parent node is loaded.

n When navigating through the track node the transaction to the parent node is done in blocks according to the condition set in the List connector (in our example DT_START).

See that the field used by the List connector is not editable in run time (see figure below).

Preload steps Mask number Binary code

Choose list dialog 1 00001

Filter list dialog 2 00010

Filter channel dialog 4 00100

Ask parameters dialog 8 01000

Display list dialog 16 10000


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e. Change now Availablesteps to 2. Save and test your presentation. Notice the following features:

n Track navigation buttons are disabled.

n The whole block is loaded in the parent node.

n DT_START related textbox is now enabled.

f. Try the rest of the Availablesteps values.

Conditional object construction

Suppose you want to add to your CXX_EXAMPLE_TRACKS_1 presentation a button showing the list of records in the track node. Here is the OBL code of such insertion:

BEGIN Button Button1

Idchannel = "CMP_M4O_COSTS3"

Idnode = "COURSES"

Image = "#Showlist"

BEGIN Evclick EvclickList

BEGIN Action_preload Action_preload2

Onok = "END_OK"

Oncancel = "UnloadTheForm"

Availablesteps = 31

END

BEGIN Action_call UnloadTheForm

Sentence = "*O*/Presentation/Form1.Unload"

END

END

END

Please do the following exercise:

Exercise

a. Add the ’Show List’ button with the OBL code listed above. Save and test your presentation.

Suppose now that you don’t know whether the CMP_M4O_COSTS3


Meta4Object has got a track connected to it. The ’Show List’ button would result as meaningless in case no track is linked.

The Designer Tool provides a mask for conditions that have to be checked before an object is constructed in run time. The mask is applied to the property Constructif which is available in a number of controls.

n Constructif: Syntax.

Constructif = ValueOfConditionMask

b. Add a suitable Constructif condition to the ’Show List’ button. Save and test the presentation.

c. Open CXX_EXAMPLE_ZLG presentation and reproduce the ’Show List’ button. Test its proper behavior. Remember this presentation was constructed over the CMP_M4O_COSTS2 Meta4Object which was not connected to a track.

Value Meaning

1 Object (and contained objects) are constructed only if a track is connected

2 Object (and contained objects) are constructed only if a track is NOT connected

4 Object (and contained objects) are constructed only if a track is connected through a List connector of 1:N type

8 Object (and contained objects) are constructed only if the Meta4Object has NOT been loaded

16 Object (and contained objects) are constructed only if the Meta4Object has been loaded

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Multicompany features in presentations

Default and customized presentations

If you remember, in the Core Tools course you learnt that you can generate default presentations that consider multicompany features. If you select a Meta4Object that is multicompany-enabled, you must decide whether you want the corresponding presentation to be multicompany or single company.

If you decide that it is single, that is to say, you do not activate the multicompany feature, the company field is hidden and you cannot display it on screen.

Now, If you choose to create a multicompany presentation, in the presentation toolbar a new button is added to open the company selection window.

What happens if instead, you want to build from a multicompany Meta4Object, your own presentation, rather than use the default?

The outcome of your multicompany enabled presentation allows the end-

Figure 4. Enabling multicompany features in default presentations


user to select which company to filter for.

Assuming that you are already familiar with the procedures for building your own presentations from exisiting Meta4Objects, what you need to do is:

n Add the corresponding toolbar control, a button, for the multicompany feature to your presentation. Upon clicking this, you need to display a filter for the different companies.

n Associate a filter that contains the list of values for companies, the parameter invoked by the button in the presentation.

n Add the corresponding menubar entry. The details of how to do this have already been covered and will not be discussed here.

Figure 5. The outcome of your multicompany enabled presentation

166

Customized presentations - params group type element for toolbar

In this case, the toolbar button type you create for the multicompany feature is set to the value, toolbarparam group. .

Figure 6. Inserting a multicompany button with the toolbar param group

1. In the Formmain part of your presentation that you are creating, double click over the toolbar area.

2. Click the Buttons tab.

3. Click insert to add a new control, a button.

4. Select Params group for type to insert the multicompany button.


Using the Toolbar Editor, make sure that you select the param group type when you define the new element for the toolbar, as this specifically adds a group of parameters for the multicompany feature. This by default includes a button for dates and another for company usually.

Customized presentations - button type element for toolbar

Alternatively you can also add an ordinary button to perform the same function. The procedure in this case is different, as shown and dicussed in the figure below. In this case, the toolbar button type you create for the multicompany feature is set to the value, button.:

Figure 7. Adding a button type element for multicompay to the toolbar

1. In the Toolbar Editor, for the Meta4Objec indicated in idchannel, select Button for Type in General Properties.

2. Add additional details such as name, text, image type to use.

3. Indicate whether it is visible, enabled and does something when click enabled.

6. Just as standard button events, you need to add instructions for loading and off-loading. Here you have Action.preload where you specifically use 32 ifor Availablesteps to invoke the corresponding companies filter.

7.. Select Params group for type to insert the multicompany button

4. Your end-result after atdding the button.

5. Select Properties to add eventclick controls.

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1. How do you load data into records of a presentation?

2. In a presentation how do you make a method executable?

3. How do you graphically represent the status of the current record in the node?

4. How do customize a presentation so that you can invoke a task from it?

Review questions



n All data and loading functionality of a Meta4Object can be implemented in one or more presentations.

n To navigate through the records based on data in a Meta4Object, add toolbar navigation controls, datagroup and edit group controls.

n In a presentation, the Action type controls invoke instructions embodied in methods or tasks for a given Meta4Object.

n The list/validate group control allows you to add a link to the presentation of the maintenance Meta4Object for data entry, to add another two links to the presentation for the track Meta4Objec to validate the data entered against the data in the track and to filter records through the track Meta4Object.

n Use pattern objects to display the current record number, total number of records in current, track or root node, as well as to display node items.

n Adding multicompany features is automatically done in a default presentation, if the multicompany feature is enabled. Otherwise, it can be customized as a toolbar button and a menubar option.


Lesson summary

á Build in all the functionality implemented in a Meta4Object into a presentation.

á Add navigation toolbars to navigate through records in a presentation.

á Run methods from a presentation.

á Add multicompany features to a presentation

á Use advanced controls and properties to add more functionality to a presentation.

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Wizard does




Exploring what the Frontend Designer Wizard does

The course ends with a review at how the Frontend Designer constructs default presentations for Meta4Objects. You will identify the structure of a default presentation, and enumerate the different controls used in such presentations.

Understanding the structure and functionality of each of the elements that appear in a default presentations will prove to be very useful, because you will be able to use the Frontend Designer Wizard to quickly generate default presentations for your Meta4Objects, and modify them according to your needs.

Introduction

Lesson objectives


n Understand the structure of a default presentations created with the Frontend Wizard.

n Identify each of the elements used in a presentation created with the wizard, and their role in the presentation.

n Alter presentations created with the wizard and customize them according to your needs.

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Meta4Mind Menu Tree



172



Exploring what the Frontend Designer Wizard does 173

You have already used the Frontend Wizard in your Meta4Object’s course for generating default presentations for your Meta4Objects.

Now that you have been trough the main elements of the designer tool you will understand what a default presentation is about. This becomes an important point as a great amount of work can be saved if you use the wizard, but commonly changes to the default presentation are required. Those changes are easily achieved if you have a deep understanding both of the designer tool and of what a default presentation is.

Run the wizard and select the Meta4Object we have been working with (CMP_M40_COSTS3). Generate its default presentation (WARNING: do not save THIS default presentation).

Main structure

By default, the main presentation’s form is structured as follows:

A tree is usually added into splFormLeft reproducing the Meta4Object’s node’s hierarchy.

SplNodeFields_Up

splFormRight/splNodeDown/splNodeFields_Up act as containers for the controls that will display the data of different nodes. A changer is also used.


Figure 10. Structure of a default presentation

174

Usually this changer contains two tabstrips:

TABSTRIP_ROOTS is reserved for the Root Node of the involved Meta4Object. Non root nodes will be represented in the other tabstrip control. The name of this non root tabstrip is taken from the root node. In our example ’COURSES’.

Generally speaking, each level in the underlying Meta4Object is assigned a Tabstrip, whose name is TABSTRIP_ParentNodeId. Each sibling in a specific level is represented by a tab in the corresponding Tabstrip. The name of the tab for each sibling is TAB_NameOfTheNode.

The specific structure of each tab is the same. The following figure shows the displayed Explorer area for the root and non root tabs (left side) and the design of both tabs (right side).

Toolbars, Patterns and Nodestatus controls play the roles you have

Figure 11. SplNodeFields_Up

Figure 12. chaChangerNodes

Figure 13. Mapping the visual area with the explorer structure


already dealt with. The NODE_COURSES and NODE_COSTS controls are Mimic controls (see Lesson 5) whose class type is initially set to Scrollpanel. The mimic class is changed by means of the first button in tlbCOSTS and tlbCOURSES. The following figures show the controls inside each of the mimics in our example.

Primary key related objects are inserted into a groupbox control. In case the wizard finds a relation in the dictionary it builds a ZLG, inserting the elements that were discussed in Lesson 5. You can see a Listgroup control in NODE_COURSES.

Figure 14. Controls inside the mimic controls I

Figure 15. Controls inside the mimic controls II

176

SplNode_Up

This block contains the controls shown in the following figure.

Inside scrPath scrollpanel two controls are inserted:

a. panTrackSection, which is a panel, where a connection with the track Meta4Object is implemented. The figure below shows the design of this panel.

The panTrackSection control has its Constructif property set to 4, which means that only in case a 1:N connection has been actually established is this object constructed (See Lesson 5).

Figure 16. SplNode_Up

Figure 17. panTrackSection


b. chaChangerPath, which is a changer control. It contains the navigation buttons for the root node. We will see later on how this changer is controlled in run time. Design is displayed in the figure below..

SplNodeFields_Down

Finally the lower area of the form is dedicated to this block. In run time it is controlled so as to show a link to child nodes when parent nodes are being displayed. The figure below shows the Explorer area of this block (left side) and the block in run time (right side).

Figure 18. chaChangerPath

Figure 19. splNodeFields_Down

178

Logic in Default Presentations

You can control which node is going to be displayed in run time in a default presentation from different controls.

The Tree as a main controller

Inside each tree node the wizard inserts an Evclick event. A number of actions are executed inside this event.

First the changer containing the nodes’ tabstrips is changed to the level representing the node (you are dealing with the objects contained in SplNodeFields_Up. See Lesson 5). This is done by means of Changeto method.

The following action makes use of Selectedtab method in order to show the corresponding tab. In our example tabstrips have only one tab, but in case a number of nodes reside at the same level, each would be represented in one of the tabs of that level’s tabstrip.

These actions depend on the relative order, that is the sequence. A tab cannot be selected before its changer has constructed the container Tabstrip.

The third action works over the changer in SplNode_Up. It will show the parent navigation buttons in case the child is visible, or it will be set to "NOTHING" in case the root node is displayed. This is also achieved with the Changeto method.

Finally SplNodeFields_Down changer is changed to the level containing the links to the levels shown in figure 16.

Figure 20. Events and actions in the tree

chaChangerNodes.Changeto(TABSTRIP_ROOTS)

TABSTRIP_ROOTS.Selectedtab(TAB_COURSES)

chaChangerPath.Changeto("NOTHING")

scrChildNodesLink/chaChildNodesLink.Changeto(PIE_COURSES)

chaChangerNodes.Changeto(TABSTRIP_COURSES)

TABSTRIP_COURSES.Selectedtab(TAB_COSTS)

chaChangerPath.Changeto(PAT_COURSES)

scrChildNodesLink/chaChildNodesLink.Changeto(PIE_COSTS)


Tabs

In case more than one node is present at the same level tabs include an Evclick event with:

a. An Action_call for changing the chaChangerPath.

b. An Action_call for changing the child related footer.

Notice that no changes between hierarchical levels take place in the tab’s Evclick. Only changes in the same level are defined here.

Footer section (SplNodeFields_Down)

In case it is displayed a number of links to the child node appear (see figure 16). Each link contains again an Evclick that reproduces the behavior of child nodes in the tree, i.e.

a. chaChangerNodes.Changeto(TABSTRIP_.......)

b. TABSTRIP_COURSES.Selectedtab(TAB_....)

c. chaChangerPath.Changeto(PAT_COURSES)

d. chaChildNodesLink.Changeto(PIE_.....)

180

Multicompany in default presentations

By default, selecting the Multicompany checkbox automatically generates an entry for the menu and creates the corresponding buttons in the toolbar.

Internally the multicompany feature depends on the company ID itself, which is used to filter by company..

Note that these controls do not have any visible eventclk controls associated.

Figure 21. Components that correspond to different features of a presentation that is multicompany enabled.



n Generating default presentations automatically includes components that define the panels, tabstrips, tabs, tree structure, nodes, and navigational keys.

n Additionally you can optionally add multicompany features to a default presentation.


Lesson summary

á Match the different parts of a presentation to the corresponding components in the presentation browser.

182

Appendix: Brief summary of some controls

The purpose of this appendix is to introduce other information which can be relevant for the understanding of the current course.

About this appendix

183

Controls for containers

n Button

n Evclick

n Groupbox

n Calendar

n Checkgroupbox

n Dataevents

n Event

n Exeblocks

n Frmobject

n Ganttable

n Link button

n Listgroup

n Mimic

n Nodehistory

n Panel

n Scrollfrmobject

n Scrollpanel

n Setpos

n Shortcut

n Slider_dates

n Table

n Template

n Textbox

n Evdbclick

n Evvalidaten Treeview

n Treenode

n Evclickn Treenode

n Rectree

n Rectreenode

n Action_setn Evclickn Evdbclickn Evdragn Evdropn Popupmenun Rectreenode

n Itemlabel

n Nodestatus

184

n Tabstrip

n Tab

n Calendarn Checkboxgroupn Dataeventsn Evclickn Eventn Exeblocksn Frmobjectn Ganttablen Link Buttonn Listgroupn Mimicn Nodehistoryn Paneln Scrollfrmobjectn Scrollpaneln Setposn Shortcutn Slider_datesn Tablen Template

n Image

n Changer

n Calendar

n Checkboxgroup

n Dataevents

n Event

n Exeblocks

n Frmobject

n Ganttable

n Link Button

n Listgroup

n Mimic

n Nodehistory

n Panel

n Scrollfrmobject

n Scrollpanel

n Setpos

n Shortcut

n Slider_dates

n Table

n Templaten Link

n Patternbox

n Combobox

n Evclick and Evvalidate

n Urlbox

n Toolbar

n Toolbarbutton

n Evclickn Evclickpressedn Popupmenun Unpressed

185

n Splittvertical

n Splittblock

n Calendarn Checkboxgroupn Dataeventsn Eventn Evhiden Evshown Exeblocksn Frmobjectn Ganttablen Link Buttonn Listgroupn Mimicn Nodehistoryn Paneln Scrollfrmobjectn Scrollpaneln Setposn Shortcutn Slider_datesn Tablen Template

n Extern

n Slider

n Evvalidate

n Label

n Evclick

n Presentation

n Action_bp

n Action_call

n Action_cmf

n Action_copy

n Action_dataprops

n Action_datatrack

n Action_dialog

n Action_edititem

n Action_execute

n Action_filter

n Action_goto

n Action_help

n Action_list

n Action_listtrack

n Action_message

n Action_method

n Action_notify

n Action_options

n Action_preload

n Action_script

n Action_set

n Action_task

n Action_tasklet

n Action_value

n Extends

186

n Forms

n Backgroundimage

n Button

n Calendar

n Changer

n Checkbox

n Checkboxgroup

n Combobox

n Dataevents

n Date

n Evload

n Evshow

n Evunload

n Exeblocks

n Extern

n Ganttable

n Groupbox

n Image

n Itemlabel

n Label

n Link

n Listgroup

n Menubar

n Mimic

n Nodehistory

n Nodestatus

n Panel

n Patternbox

n Rectree

n Scrollpanel

n Shortcut

n Slider

n Slider_dates

n Splitthorizontal

n Splittvertical

n Forms (condt)

n Table

n Tabstrip

n Textarea

n Textbox

n Toolbar

n Treeview

n Urlbox

187

Appendix: Mouse events


About this appendix

189

Mouse events

n Evclick

n Menu

n Menuitem

n Button

n Label

n Itemlabel

n Textbox

n Image

n Extern

n Patternbox

n Mimic

n Shortcut

n Tab

n Toolbarbutton

n Treenode

n Rectreenode

n Evclickchecked & Evclickunchecked

n Menu

n Menuitem

n Extern

n Mimic

n Evclickpressed & Evclickunpressed

n Extern

n Mimic

n Toolbarbutton

n Evdbclick

n Textbox

n Combobox

n Image

n Extern

n Calendar

n Date

n Mimic

n Textarea

n Column

n Rectreenode

n Evdrag & Evdrop

n Rectreenode

n Extern

n Mimic

190

Appendix: Evvalidate: Triggering mechanisms


About this appendix

191

n Extern

n Mimic

n Date

n Dataevents

Triggered when losing focus

n Textbox

n Column

n Textarea

n Calendar

n Combobox

Triggered when clicking

n Checkbox

n Optionbutton

n Slider

Evvalidate

192

Appendix: Data-related events


About this appendix

193

n Evaftermove

n Dataevents

n Extern

n Mimic

n Evafternew

n Dataevents

n Extern

n Mimic

n Evafterdelete

n Dataevents

n Extern

n Mimic

n Evafterpersist

n Dataevents

n Extern

n Mimic

n Evafterchangeitem

n Dataevents

n Extern

n Mimic

Data-related events

194

Appendix V: Other events


About this appendix

195

Other events

n Evnotify

n Action_task

n Action_tasklet

n Evload

n Form

n Tab

n Changer

n Evunload

n Form

n Evshow

n Form

n Splittblock

n Extern

n Mimic

n Evhide

n Extern

n Mimic

n Evtab

n Extern

n Mimic

n Table

n Evbefnav

n Urlbox

n Rectreenode

n Extern

n Mimic

n Evnavcom

n Urlbox

n Rectreenode

n Extern

n Mimic

n Evoledrop

n Rectreenode

n Extern

n Mimic

n Evoledrag

n Rectreenode

n Extern

n Mimic

196

Appendix VI: Some properties


About this appendix

197

Properties set #1

Comments on Grants:

n Bit Mask

Properties

Name Meaning Run time Mandatory

Classname Name of the class by which the component is represented

N Y

Alias Logical name given to the component

N Y

Idchannel ID of the Meta4Object linked to the component

N N

Idnode ID of the node linked to the component

N N

Iditem ID of the item linked to the component

N N

Idchannelkey Advanced use. Password for the Meta4Object access

N N

Idchannelalias Advanced use. Logical name given to the Meta4Object

N N

Idaccessalias Advanced use. Name given to the Meta4Object access

N N

Grants Bit map reflecting permissions

N Y

Grant Mask number Binary code

Read 1 00001

New 2 00010

Update 4 00100

Delete 8 01000

Execute 16 10000

198

n Default value: 31(all)

Properties set #2

Properties set #3

Name Meaning Default Mandatory

Font Type of font MS Sans Serif

Y

Backcolor Background color (in some components)

Gray Y

Forecolor Foreground color (in some components)

Black Y

Borderstyle Border (in some components)

Single Fixed

Y

Alignment For text inside the component (Left/Centered/Right=0/2/1)

0 Y


Top Referred to the container component. Vertical distance

Visual D. Y

Left Referred to the container component. Left distance

Visual D. Y

Width Width of the component Visual D. Y

Height Height of the component Visual D. Y

Align Referred to the container component. Type of alignment

Null Y

199

Comments on Align. Possible values:

Properties set #4

Top Stuck to the top of the container. The component changes its width to the container´s. The component keeps its height.

Bottom Stuck to the bottom of the container. The component changes its width to the container´s. The component keepsits height.

Left Stuck to the left of the container. The component keeps its width. The component changes its height to the container´s.

Right Stuck to the right of the container. The component keeps its width. The component changes its height to the container´s.

Bottomfixed Stuck to the bottom of the container. The component changes its width to the container´s. The height of the component changes according to the component´s Top value

Rightfixed Stuck to the right of the container. The component changes its width according to it´s Left value. The component keeps its height.

All Adjust to the container´s size.


Enabled The component is enabled. (Enabled/Disabled = 1/0)

1 Y

Visible The component is visible. (Visible/Not visible) = 1/0

1 Y

Editable The component contains a text which is editable (1) or not editable (0)

1 Y

200

Properties set #5

Some more properties

Action

n Values

n Addfilters

n Copy

n Cut

n Delete

n Execute

n Executewithoutparams

n Filters

n Find

n First

n Firstdoc

n Last

n Lastdoc

n Load

n New

n Next

n Nextdoc

n Paste

n Previousdoc

n Redo

n Reload

n Removefilters

n Save

n Undo

n Unload

Name Meaning Default

Text Text appearing in run time. Admits multi language values

Same as Alias

201

Mousecursor

n Image of the mouse cursor when passing over the component.

n Values:

n Arrow

n Arrowhourglass

n Arrowquestion

n Crosshair

n Default

n Hand

n Hourglass

n Ibeam

n Iconpointer

n Nodrop

n Sizeall

n Sizenesw

n Sizepointer

n Sizewe

n Uparrow

Image

n An image stored in the disk can be used by a control with the Image property. In that case values can be given to this control according with the reference of the Image Folder.

n A number of images are available. Their values are:

n #Calculator

n #Calendar

n #Chnfinal

n #Chnint

n #Chnmedium

n #Closebook

n #Delrecord

n #Erasefilter

n #Execute

n #Forbbiden

202

n #Forbbiden_1

n #Forbbiden_2

n #Four

n #Gofirst

n #Golast

n #Gonext

n #Goprevious

n #Menu

n #Newrecord

n #Openedbluebook

n #Openedredbook

n #Save

n #Search

n #Showfilter

n #Showlist

n #Sort

n #Statusdeleted

n #Statusdeleted1

n #Statusdeleted2

n #Statuseof

n #Statuseof1

n #Statuseof2

n #Statusmodified

n #Statusmodified1

n #Statusmodified2

n #Statusnew

n #Statusnew1

n #Statusnew2

n #Statusnormal1

n #Statusnormal2

n #Undo

203

Appendix VII: Events contained in components


About this appendix

205

Events

Component Event

Presentation Presentation

Form Evshow

Evload

Evunload

Tab Evclick

Evload

Action_task Evnotify

Action_tasklet Evnotify

Label Evclick

Button Evclick

Textbox Evvalidate

Evdbclick

Evclick

Splittblock Evshow

Evhide

Changer Evload

Checkbox Evvalidate

Combobox Evvalidate

Evdbclick

Extern See figure bellow

Image Evdbclick

Evclick

Patternbox Evclick

206

Toolbarbutton Evclick

Evclickpressed

Evclickunpressed

Urlbox Evbefnav

Evnavcom

Slider Evvalidate

Calendar Evvalidate

Evdbclick

Treenode Evclick

Rectreenode See figure bellow

Date Evvalidate

Evdbclick

Dataevents Evvalidate

Evaftermove

Evafternew

Evafterdelete

Evafterpersist

Evafterchangeitem

Evbeforepersist

Menu Evclick

Evclickchecked

Evclickunchecked

Menuitem Evclick

Evclickchecked

Evclcickunchecked

Mimic See figure bellow

Shortcut Evclick

Slider_dates Evchange

Table Evtab

Component Event

207

Column Evvalidate

Evdbclick

Textarea Evvalidate

Evdbclick

Figure 22. Events for the Extern component

Component Event

208

Figure 23. Events for the Rectreenode component

209

Appendix VIII: Methods


About this appendix

211

Methods

Component Method

Button Enabled

Text

Visible

Calendar Backcolor

Copy

Cut

Enabled

Forecolor

Paste

Text

Visible

Changer Changeto

Checkbox Backcolor

Copy

Cut

Enabled

Forecolor

Paste

Value

Visible

212

Column Backcolor

Copy

Cut

Enabled

Forecolor

Paste

Text

Visible

Combobox Backcolor

Copy

Cut

Enabled

Forecolor

Paste

Text

Visible

Exeblocks Call

Form Print

Unload

Validate

Validateform

Image Image

Itemlabel Backcolor

Enabled

Forecolor

Text

Visible

Component Method

213

Menu Checked

Click

Enabled

Visible

Menuitem Enabled

Visible

Checked

Mimic Class

Popupmenu Show

Rectreenode Condition

Checkcurrentpos

Shortcut Click

Slider Backcolor

Enabled

Forecolor

Value

Visible

Splittblock Floating

Blocked

Textarea Backcolor

Copy

Cut

Enabled

Forecolor

Paste

Text

Visible

Component Method

214

Textbox Backcolor

Copy

Cut

Enabled

Forecolor

Paste

Text

Visible

Toolbarbutton Click

Enabled

Pressed

Text

Visible

Urlbox Goback

Goforward

Gohome

Refresh

Stop

Url

Component Method

215

Appendix IX: Some more components


About this appendix

217

Action_copy

Action_dataprops

Some more components

Property name Values

Set #1 See Appendix I

Action Cut

Copy

Paste

Undo



Mappersist

Mapload*

Mapundo

Mapdelete

Autoload† 0/1

Load‡ True/False

Unload** True/False

Reload

Statistics

Workdates

Action Addfilter,Copy, Copydata, Cut, Cutdata, Delete, Execute, Executewithoutparams, Filters, Find, First, Firstdoc, Last, Lastdoc, List, Load, New, Next, Nextdoc, Paste, Pastedata, Previous, PreviousdocRedo, Removefilters, Save, Silentsave, Undo, Unload

218

Actionifinvalidpos Addfilter,Copy, Copydata, Cut, Cutdata, Delete, Execute, Executewithoutparams, Filters, Find, First, Firstdoc, Last, Lastdoc, List, Load, New, Next, Nextdoc, Paste, Pastedata, Previous, PreviousdocRedo, Removefilters, Save, Silentsave, Undo, Unload

Actionifvalidpos Addfilter,Copy, Copydata, Cut, Cutdata, Delete, Execute, Executewithoutparams, Filters, Find, First, Firstdoc, Last, Lastdoc, List, Load, New, Next, Nextdoc, Paste, Pastedata, Previous, PreviousdocRedo, Removefilters, Save, Silentsave, Undo, Unload

Mvcaction

*. Maps the Load action with the item execution†. Assigns this property to the Meta4Object‡. Loads the Meta4Object**. Unloads the Meta4Object


219

Action_datatrack

Action_execute

Propert name Values


Idtrackchannel

Idtrackchannelalias

Idtrachchannelkey

Idtrackaccessalias

Idtracknode

Idtrackitem

Trackgrants

Idtrackpresentation



Action*

*. Name of actions that can be executed

Globalrefresh

Channelrefresh

Accessrefresh

Branchrefresh

Noderefresh

Recordrefresh

Itemrefresh

Validate Boolean

220

Action_method

Action_method enables the execution of a given method defined in a Meta4Object with the possibility of transferring values in both directions



Sourceargs

Sourceobjs

Targetobjs

Returnobjs

Ontrue

Onfalse

Onerror

221

Index

AAbsolute reference facility 68Absolute referencing 66Action_bp 127Action_call 73Action_dataprops 123Action_dialog 94Action_goto 91Action_list 117Action_method 125Action_preload 104Action_script 131Action_set 72Action_task 74Action_value 116Adding controls from the control palette to a

form 23Adding controls to a form from the "Insert

Component" option 25Adding visual and non visual components with

the explorer 40Advanced properties of the ZLG 148Askbeforeclose property 91Availablesteps property 104

CChanging properties in run time 72Changing the grid size 20Closing the OBL editor 21Conditional object construction 163Connecting presentations 74

Constructif 164Control Button 34Control Changer 85Control Checkbox 33, 132Control Checkboxgroup 34Control Combobox 32Control Groupbox 33Control Image 31Control Label 30Control Link 32Control Mimic 128Control palette 23Control Panel 84Control Scrollpanel 84Control Slider 35Control Split 57Control Tabstrip 84Control Textbox 34Control Urlbox 32

DData properties 102

EEditing the OBL code of a presentation 20Exeblocks 94Extends 74

FFlow control 91

ccxxiii

Index

Frontend Designer interface 16Function Clear 144Function List 145Function Zoom 144

GGeneral properties of Listgroup 139Grant property 91

IInserting a new form in a presentation 18

LLinking presentations to Meta4Objects 102Listgroup 134Loading options 103Logic behind Default Presentations 179

MMainargs and Mainobjs 140Menus 58Modal property 90Multi language 109Multi language text 89

NNew Presentation 17Nodestatus 118

OOnok, Oncancel properties 91

PPatternbox 118Presentation context and context variables 75

Presentation Explorer 40Previewing a presentation 18

RReferring to properties of other objects 66Registername property 90Relative referencing 67RunTime variables 77

SSaving a presentation 25Saving code from the FrontEnd Designer and

inserting code into the OBL editor 38Setting properties in design time using the

OBL editor 35Setting properties in design time using the

Properties dialog box 27Specific patterns 159SplNode_Up 177SplNodeFields_Down 178SplNodeFields_Up 174Startupposition property 90Steps in the preload 161Structure of the Listgroup control 137

TTable 119Targetitems and Targetobjs 142The Function control 137The Properties dialog box 47The Record Insert Wizard 112The Record Insert Wizard and the ZLG 151The syntax checker 36Toolbar groups 122Toolbar Navigation Groups 158Toolbars 57Trees 85

VVirtual forms 85

ccxxiv

Index

WWindowstate property 90

Working with tracks 154

ccxxv

present ac i ones

Documents

control palette

control slider

control textbox

control groupbox

control combobox

control checkboxgroup

control urlbox

control link