ts drupal6 module development v0.2

Boutique product development company It is amazing what you can accomplish when you have a client-centric team to deliver outstanding products.

Drupal6 Module Development Guide Furqan Razzaq| Drupal Mentor

Drupal6 Module Development Guide Topics covered in the presentation

• What is Module

• Collaboration Over Competition

• Telling Drupal About Your

Module

• Hooks

• Block Content

• Other Files

Furqan Razzaq | Drupal Mentor

Drupal6 Module Development Guide

What is a Module


A module simply is a collection of procedures that are

logically combined in a group of files.

These procedures can he hooks, menu callbacks,

forms, themes or your custom, or even

jquery/javascript snippets.


Kinds of Module


There are three kinds of Drupal Modules

1. Core

2. Contributes

3. Custom


Core Modules


• Core modules are the ones that are shipped with Drupal install and

are approved by the core developers and the community.

• The location of these modules is under [installation directory/modules]

• There are also a bunch of include files that these modules use.

Include files are located under [installation directory/includes]


Custom Module Development


)

• Before we start, following are some helpful links to guide you through

the development process:

• http://drupal.org/node/326 [working with Drupal API]

• http://api.drupal.org/api/drupal [Drupal API reference]

• http://drupal.org/node/7765 [Best Practices on creating and maintaining

projects]

• http://drupal.org/coding-standards [coding standards]

• http://drupal.org/writing-secure-code [writing secure code]

We know its a lot to process in one go, but you will get to it eventually.

http://drupal.org/node/326

http://api.drupal.org/api/drupal


http://drupal.org/coding-standards



http://drupal.org/writing-secure-code






Collaboration Over Competition


• Module Duplication is a growing concern with in Drupal community,

which values joining forces on improving one awesome project rather

than building several sub-standard ones that overwhelm end users

with choices.

• So what to do? Search existing modules before you start embarking

on your own quest.


Let’s Jump Over Module Development


• So, what do you need:

• Basic PHP knowledge (of course ) including syntax and concept of

PHP Objects

• Basic understanding of database tables, fields, records and SQL

statements

• A working Drupal installation

• Webserver access (in our case, its any set of Apache/PHP/MySql)


Let’s Develop a Single Module


• Module Name

• Telling Drupal about your module

• Declaring block content


Getting Started


• Create Following files

• .info

• .module


Telling Drupal About Your Module


1. How to let Drupal know the module exists?

2. Drupal hook described: hook_help


How to Let Drupal Know That Module Exists


• Tell Drupal about your module in modulename.info file. File content

should be like…

• Name (Required) = Color

• Description (Required) = Allows the user to change the color scheme

of certain themes.

• package = Core - optional

• Core (Required) = 6.x

• version = "6.20"

• project = "drupal"

• datestamp = "1292447788"


Telling Drupal About Your Module


1. How to let Drupal know the module exists?

2. Drupal hook described: hook_help


Drupal Hooks


Drupal Hook???


Apparently Not


• Drupal's module system is based on the concept of "hooks".

• A hook is a PHP function.

• Hooks allow modules to interact with the Drupal core.

• Each hook has a defined set of parameters and a specified result

type.

• A module need simply implement a hook.


How to Declare Hooks?


• modulename_hookname()

• color_help()


Where/When Hooks are Used?


• Drupal determines which modules implement a hook and calls that

hook in all enabled modules that implement it.


Common Hooks


• hook_help()

• hook_perm()

• hook_init()

• hook_theme()

• hook_block()

• hook_menu()


Help Hooks – a Module File Entry


/**

* Implementation of hook_help

*/

function modulename_help($path, $arg) {

switch ($path) {

case 'admin/help#color':

$output = '<p>'. t('The color module allows a site administrator to

quickly and easily change the color scheme of certain

themes.’ ).'</p>';

return $output;

}

}


Specify the Available Permissions


• Tell Drupal who can use your module.

/**

* Implementation of hook_perm

*/

function modulename_perm() {

return array('access site-wide ', 'administer colors');

}


Hook_init ()


• This hook is run at the beginning of the page request.

1. Add CSS or JS that should be present on every page.

2. Set up global parameters which are needed later in the request


Cont..Hook_init ()


function modulename_init() {

$path = drupal_get_path('module', ‘modulename');

drupal_add_js($path . '/filename.js');

drupal_add_css($path . ‘/filename.css', 'module', 'all', FALSE);

}

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_i

nit/6

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_init/6

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_init/6


Hook_Theme ()


function modulename_theme($existing, $type, $theme, $path) {

}

• Write theme funtions


Declaring Block Content


/** * Implementation of hook_block(). * @param string $op one of "list", "view", "save" and "configure" * @param integer $delta code to identify the block * @param array $edit only for "save" operation */

function modulename_block($op = 'list', $delta = 0, $edit = array()) { switch ($op) {

case 'list':

$block = array();

$block[0]["info"] = t('assets');

return $block;

break;


Declaring Block Content Cont..


case 'view':

$block['subject'] = 'assets';

$block['content'] = get_block_content();

return $block;

break;

}

}

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_

block/6

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_block/6

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_block/6


Hook Menu


• Define menu items and page callbacks.

• This hook enables modules to register paths in order to define how URL

requests are handled.

• This hook is rarely called (for example, when modules are enabled), and

its results are cached in the database.


Hook Menu Cont..


function modulename_menu() {

$items['abc/def'] = array(

'page callback' => 'mymodule_abc_view',

'type' => MENU_CALLBACK,

'access callback' => true,

);

return $items;

}

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_

menu/6

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_menu/6

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_menu/6


Useful Links


• hook_form_alter(&$form, &$form_state, $form_id)

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_form_alter/6

• hook_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_nodeapi/6

• hook_user($op, &$edit, &$account, $category = NULL) http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_user/6



http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_nodeapi/6

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_nodeapi/6

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_user/6

http://api.drupal.org/api/drupal/developer!hooks!core.php/function/hook_user/6


.Uninstall File


• Remove all tables that a module defines.

• http://api.drupal.org/api/drupal/includes!common.inc/function/drupal_

uninstall_schema/6

http://api.drupal.org/api/drupal/includes!common.inc/function/drupal_uninstall_schema/6

http://api.drupal.org/api/drupal/includes!common.inc/function/drupal_uninstall_schema/6


Useful Links


1. Creating modules - a tutorial: Drupal 6.x

2. Creating Our First Module (1.3M PDF)

3. Coding standards

4. http://www.drupal.org








http://www.packtpub.com/files/Learning-Drupal-6-Module-Development-Sample-Chapter-Chapter-2-Creating-Our-First-Module.pdf


http://www.drupal.org/

ts drupal6 module development v0.2

Documents