Is It Possible To Create My Own Shortcode

Question

I'm building a module. I want to be able to use a shortcode (template directive) in my CMS static blocks, such as the following:

{{store url=""}}

I want to call my own module's frontpage blocks using this method. Is this even possible? Google has turned up nothing about writing my own.

Answer 1

You need to override this model: Mage_Cms_Model_Template_Filter Mage_Widget_Model_Template_Filter and add a method for your own shortcode. Let's assume your short code is called 'custom', you need to add a method called customDirective($construction) that handles your shrotcode.
To get an idea on how that method should look like, take a look at Mage_Core_Model_Email_Template_Filter::storeDirective(). This method handles the store shortcode.

To get the parameters passed to the short code use this:

$params = $this->_getIncludeParameters($construction[2]); 

After processing them you need to return a string value that will replace the {{custom ...}} placeholder.

[Edit]
I realized my mistake. The Widget module changes the template processor. Here is the piece of code that worked for me.
file app/etc/modules/Easylife_Widget.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Easylife_Widget>
            <active>true</active>
            <codePool>local</codePool>
            <depends>
                <Mage_Widget />
            </depends>
        </Easylife_Widget>
    </modules>
</config>

file app/code/local/Easylife/Widget/etc/config.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Easylife_Widget>
            <version>0.0.1</version>
        </Easylife_Widget>
    </modules>
    <global>
        <models>
            <widget>
                <rewrite>
                    <template_filter>Easylife_Widget_Model_Template_Filter</template_filter>
                </rewrite>
            </widget>
        </models>
    </global>
</config>

file app/code/local/Easylife/Widget/Model/Template/Filter.php

<?php

class Easylife_Cms_Model_Template_Filter extends Mage_Widget_Model_Template_Filter{
    public function customDirective($construction){
        $params = $this->_getIncludeParameters($construction[2]); 
        return print_r($params, 1);
    }
}

Clear the cache.
Now when I enter {{custom}} in the page content I get back Array().
If I enter {{custom var1="6"}} I get Array ( [var1] => 6 ).

Answer 2

Given the popularity of this question, thought I'd add this; there's (obviously) a similar way to mimic this functionality. If the block type of core/template is used, we can access the data array using getData().

For example, if we create a block in CMS similar to the following:

{{block type="core/template" name="a_sweet_title" bimg="my_profile_pic.jpg"
    bwidth="250" bheight="500" template="mymodule/my_template_file.phtml"}}

Then we can access that data in the phtml file using getData():

$imgSrc = $this->getData('bimg');
$blockWidth = $this->getData('bwidth');
$blockHeight = $this->getData('bheight');

Or, better yet, even retrieve a record/collection using a block parameter:

$collection = Mage::getModel('mymodule/mymodule')->load($theId);

Armed with that knowledge, maybe ask yourself; 'Do I really need a custom shortcode'? Hope it helps.