Working with Shortcodes

New in version 2.2.

Starting with Omeka 2.2, Omeka offers shortcode support. The core comes with several default shortcodes, and plugins can register their own, too. Users can then insert shortcodes within free text, and Omeka will replace the shortcode with whatever markup is returned from the registered callback. For more information shortcodes from a user’s persepective, see the Shortcodes page on the Omeka Codex.

You can add support for shortcodes in two ways. First, plugins can add their own shortcodes. For example, the Exhibit Builder plugin provides several shortcodes for including Exhibits within other pages, and the Geolocation plugin adds a shortcode for embedding a map. Second, plugins and themes can support shortcodes within user-provided text. The Simple Pages plugin is the obvious example of this: users can include shortcodes in the content of pages.

Adding a new shortcode

Shortcodes are added through the add_shortcode function. The function takes only two arguments: the name of the shortcode (what the user will type at the beginning of the shortcode) and a callback. A plugin adding a shortcode should call add_shortcode in its initialize hook.

The callback will be called whenever a shortcode is encountered in text, and is responsible for returning the markup that will actually be rendered on the page in place of the shortcode. Two parameters are passed to the callback. The first is an array of the arguments the user included in the shortcode (i.e. [my_shortcode arg1="value 1" arg2="value 2"] results in array('arg1' => 'value 1', 'arg2' => 'value 2') as the first parameter). The second argument is an Omeka_View instance, to simplify calling view helpers or reading data from the view.

So, in all, a plugin can add a shortcode with very little code:

class MyPlugin extends Omeka_Plugin_AbstractPlugin
    protected $_hooks = array('initialize');

    public function hookInitialize()
        add_shortcode('my_shortcode', array($this, 'shortcode'));

    public function shortcode($args, $view)
        return 'This is a very simple shortcode.';

Supporting shortcodes in user input

The flipside of adding new shortcodes is supporting shortcode replacement in text input by the user. To support shortcodes, you only need to pass the text through the shortcodes view helper.

Assuming $text is some text input by the user, you barely need to change your code that would have normally output the text:

/* No shortcode support: */
echo $text;

/* Shortcode support: */
echo $this->shortcodes($text);

You can also use the shortcodes helper on static text:

echo $this->shortcodes('[my_shortcode]');