jax 08 - agile rcp

Agile RCPPresenter First using Spring Dynamic Modules

Heiko Seeberger | metafinanz

2008-04-22 Heiko Seeberger | metafinanz2

123

Concepts

Application to RCP

Agile RCP framework


What is agile?

• Develop exactly what is required.• Test-driven development.• …


How can we be agile?

We need:• Agile process driving the design.• Architecture allowing for unit-testing.• …


Can UI development be agile?“User interfaces are hard to unit-test”:• Tangling of presentation and logic.• Dependency on concrete UI

technologies.


UI logic

Example: Unit-testing UIs

Verify input Invoke addition


Test Cases

How to implement these Test Cases?• Non-digits => Log error “Illegal format

…”.• 123 + 999 => 1122.

Example


Vanilla approach

Put “everything” into one Composite:• Text, label and button controls.• Handling button clicks:

– Verify input, possibly display error.– Invoke “business logic”.– Show result.

Example


Vanilla tastes, but …

• Quick win for the implementation.• Disastrous for testing.

– Why?– Let me show you (demo) …

Example


Any better ideas?


Use Model-View-Presenter

Similar to MVC, but:• Controllers for

widgets, presenters for views.

• Widgets hand off user gestures to presenter.

View

Presenter

Model


Passive View

• Does not listen to model updates.

• All UI logic in presenter.

passive

UI logic

View

Presenter

Model

Testing UI logic == Presenter testing


Interface abstractions

• Interfaces for model and view.

• Mock model and view to test presenters. passive

UI logic

IView

Presenter

IModel

PresenterTest

MockView MockModel

Presenter testing == EasyTesting UI logic == Easy


Presenter First architecture• MVP.• Passive View.• Interface

abstractions for model and view. passive

UI logic

IView

Presenter

IModel


Presenter First process

IView

Presenter

IModel

The user can query for books by entering the title in the query form …

User Story-onQuery()…

+getName()…

+getBooks()…

Requirements drive the design.


Presenter First (PF) answers:• How can we be agile?• Can UI development be agile?

– Delivers an agile process driving the design.

– Based on an Architecture enabling unit-testing.

– Untangles presentation and logic.– Abstracts from concrete UI technologies.


Presenter First approach

IView

Presenter

IModel

The user can enter two addends. Clicking “=“ will add and show their sum.

User Story

-handleAdd()…

+getAddend01()+getAddend02()+setSum()

+add()…

Example

+getAddend01()+getAddend02()+setSum()+registerAddHandler()


Presenter First approach

Example

Demo …


Test the presenter

Example


Full test coverage for UI logic

Example


123

Concepts

Application to RCP

Agile RCP framework


How to create the MVP triads?

IView

Presenter

IModel

MockView MockModelView Model


Application context

Use Spring!

Presenter

View Model


Bundle

Application context

Spring Dynamic Modules

Integration of OSGi/RCP and Spring:• Active bundle Spring application context.

Bean

BeanBean


Example

Application context

ContactsPresenter

ContactsView ContactsModel


Bundle

Application context

Sharing beans across bundles• Exporting beans as OSGi services.• Importing OSGi services as bean references.

Bean

BeanBean

Bundle

Application context

Bean

Bean


Im-/exporting services

• Importing an OSGi service:

• Exporting a bean as OSGi service:<service ref="personRepository" auto-export="interfaces"></service>

<reference id="personRepository" interface="org.agilercp.demo.contacts.IPersonRepository"></reference>


org.agilercp.demo.contacts.ui

Application context

Example

ContactsModel

org.agilercp.demo.contacts

Application context

PersonRepository


How to create ViewParts?

Workbench

views xPt

ViewPart

• ViewParts are created by the workbench.• How can we use the Spring created ones?


The workbench is flexible!

Workbench

ViewPartFactory

views xPt

Application context

Presenter

View Model

IExecutable-ExtensionFactory

IExecutable-Extension

getBean viewId(viewId)


Example


Application context

Dialog ViewPart

How to create Dialogs?

Presenter

View Model

Presenter

View Model

dialog

• Let Spring create the Dialog.• Inject it into opening MVP triad.


Example


123

Concepts

Application to RCP

Agile RCP framework


Agile RCP

• Presenter First framework for RCP.• Emerged from a real-world project.• Open Source: http://

sourceforge.net/projects/agilercp.• Website: http://agilercp.metafinanz.de.

http://sourceforge.net/projects/agilercp


http://agilercp.metafinanz.de/



Challenge

• Spring instantiates views,• but controls created later.

How can a presenter initialize its view before it is shown?


Agile RCP supports MVP life cycle


Showing views …

M and V are instantiated.

P is instantiated and M and V are

injected.

P initializes V.

P registers itself as IViewListener to V.

V is created.

V is shown.


Agile RCP delivers a view factory• Has access to Spring application

context.• Gets workbench parts by view/editor id.


Agile RCP delivers a lot more• Base classes for ViewParts.• Base classes for Dialogs.• Utility classes.• …• And a lot more is planned!


Agile RCP approach

Example

Demo:New requirement: Initialize view

with“123 + 999 = 1122”


Thank you!

• Website: http://agilercp.metafinanz.de• Agile RCP at sourceforge.net:

http://sourceforge.net/projects/agilercp• Contact me:

[email protected]




mailto:[email protected]

jax 08 - agile rcp

Technology