Creating a "Hello World" plugin

Let's begin

First, we create the actual file that will be executed: /deki/plugins/special_page/special_helloworld/special_helloworld.php

<?php
if (defined('MINDTOUCH_DEKI'))
{
    // register this plug-in's location, and associate a PHP function to execute at this URL
    DekiPlugin::registerHook('Special:HelloWorld', 'wfSpecialHelloWorld');
}

// DekiPlugin passes in three parameters; the last two as references; ultimately $html is returned to the end user
function wfSpecialHelloWorld($pageName, &$pageTitle, &$html)
{
    $pageTitle = 'Hello, World!';
    $html = 'Hello, world.';
}

In order to allow this file to be executed, we must white-list its execution through LocalSettings.php: 

$wgDekiSpecialPages[] = 'special_helloworld';

If you now visit http://your-site/Special:HelloWorld, it will return the phrase "Hello, world." (The sample is attached)

Example: "Hello World" special page plug-in (Expanded)

MindTouch includes a SpecialPagePlugin class which simplifies your ability to push additional code down the pipe (primarily JS and CSS). This example will be far more useful if you're looking to create a robust special page. To create a "Hello World" which takes advantage of this, create /deki/plugins/special_page/special_helloworld_expanded/special_helloworld_expanded.php

<?php

if (defined('MINDTOUCH_DEKI'))
{
	// create a hook, but execute from class "SpecialHelloWorld" with method "create"
	DekiPlugin::registerHook('Special:HelloWorldExpanded', array('SpecialHelloWorldExpanded', 'create'));
}

class SpecialHelloWorldExpanded extends SpecialPagePlugin
{
	protected $pageName = 'HelloWorld';

	public static function create($pageName, &$pageTitle, &$html)
	{
		$Special = new self($pageName, basename(__FILE__, '.php'));
		// this will automagically look in your resources file
		// $pageTitle = $Special->getPageTitle();
		$pageTitle = 'Hello, World (Expanded)';
		$html = $Special->output();
	}
	
	function &output()
	{
		$this->includeSpecialCss('special_helloworld_expanded.css');
		$this->includeSpecialJavascript('special_helloworld_expanded.js');
		return '<span id="helloworld">Hello, world.</span>'; 
	}
}

For this example, a custom CSS file and custom JS file were also included. The CSS file made the text bolded and bigger, while the JS hooked a jQuery event which would hide the "Hello, World" text when clicked: 

special_helloworld_expanded.css:

#helloworld {
    font-weight: bold;
    font-size: 16px;
}

special_helloworld_expanded.js:

Deki.$(document).ready(function(){
    Deki.$('#helloworld').click(function() {
        Deki.$(this).hide();
    });   
});

In order to allow this file to be executed, we must white-list its execution through LocalSettings.php: 

$wgDekiSpecialPages[] = 'special_helloworld_expanded';

If you now visit http://your-site/Special:HelloWorldExpanded, it will return the phrase "Hello, world.", which if you click, will hide the text (The sample is attached)