Help:Writing a gadget

How to add utility gadgets for all users of the wiki. These gadgets will be hidden from the Preferences page. The finished gadgets can be found from the Special:Gadgets page.

1. Add the following line to MediaWiki:Gadgets-definition:

* mygadget[ResourceLoader|hidden|default]|mygadget.js|mygadget.css

2. Enter some description in MediaWiki:Gadget-mygadget

My gadget template, do not edit.

3. Add the following JavaScript code to MediaWiki:Gadget-mygadget.js:

/**
 * mygadget Gadget JavaScript
 * Authors: 
 * Description: This gadget replaces the content within elements with the class "mygadget"
 *              with the text "Hello, World!" and appends it below the existing content.
 */

$(document).ready(function() {
    // Find all elements with the class "mygadget" and append a line break and "Hello, World!" after the existing content.
    $('.mygadget').each(function() {
        var helloWorld = $(this).find('<!-- BEGIN-HELLO-WORLD -->');
        helloWorld.after('<br />Hello, World!');
    });
});

4. Edit MediaWiki:Gadget-mygadget.css:

5. Create Template:mygadget with the following content:

<div class="mygadget">
This is some text.<br />
<!-- BEGIN-HELLO-WORLD -->
Hello, World!
</div>

6. Use the following code to insert your gadget on a page:

Some content above.
{{mygadget}}
Some content below.