When I first started using Drupal, it was simple matter of installing and using it. Then came the task of learning how to theme. But there came a point where required functionality needed to be coded in Drupal rather than just being able to use the GUI interface. One requirement, that started my path towards learning on creating Drupal modules, was custom front-end page and serving ajax pages. I found creating those pages with a custom module easier than some other ideas. But before being able to create a custom page (which wil be discussed in later tutorial) I needed to create a custom module where I could code custom page module. This tutorial will go through steps on how to create a custom module.

A quick note, I will be going through just the basics steps on how to add module. But wherever apppicable, I will be providing links where you can get detailed information. So, think of this tutorial as well explained reference document with information on each resource and not just the reference.

[b]Requirements[/b]: Drupal 7

To start with, we will assume that the name of this module will bemymodule. So, create a folder called mymodule in sites/all/modules folder. We need at least 2 files for a module to work. You can add as many other files as you need to extend your module but these are only 2 required files for a module to work.

First file is to module information like name, description, version etc. This will be used by Drupal to determine what name, version etc. to show while viewing module list. We will now create [i]mymodule.info[/i] file in mymodule folder. This file will contain following information:

[code]
name = My Custom Module
description = “Custom module to add custom functionality”
version = 7.x-1.x-dev
core = 7.x
project = rattanpal
[/code]

Most of this file is self-explanatory. Every module has a name, description, version and core. More information on these options can be found at http://drupal.org/node/542202. Next and last required file for adding a custom module is [i]mymodule.module[/i] file. This file controls options for module access, custom menu entries, module settings etc. Following is the code that we will put in our myodule.module file; which will be explained shortly.

[code type=”php”]
<?php
/**
* Implements hook_help.
*
* Displays help and module information.
*
* @param path
* Which path of the site we're using to display help
* @param arg
* Array that holds the current path as returned from arg() function
*/
function mymodule_help($path, $arg) {
switch ($path) {
case "admin/help#mymodule":
return '

‘. t(“Displays Help for MyModule”) .’

‘;
break;
}
}
?>
[/code]

[i]mymodule_help[/i] is Hook to implement Help for your module. You will eventually want to enter more information for users to help them how to use your module. This is explained in detail at http://drupal.org/node/1095546

If you were osave these changed and go to admin/modules at this moment, you will see your module listed in list of modules. At this point, you should be able to enable/install your custom module.

We will continue with this in another tutorial where we will use this module to add a custom page. We can use that page to deliever any type of content (for example, ajax to server json content or a custom front page). We will also discuss how to use permissions to secure that page, if needed.

EDIT: Part 2 of this tutorial is at Drupal 7: Custom Module – Part 2.