Why is my custom class file being included but not being used?

Question

I'm currently working on this question: How can I add category IDs as a class on the top menu?

So far, I have set up a new class file that extends Mage_Page_Block_Html_Topmenu

I've included the toHtml and _toHtml functions, and am just trying to return a simple string from those functions to make sure it works. I have also included a simple string saying "HTML Test" outside of the php tags, to check whether or not the file is being included.

Now, I can see "HTML Test" at the top of the page, so my new class file IS being included, but my functions toHtml and _toHtml are not being used.

Here's the details:

My new class file is /app/code/local/Coffeesh0p/Topmenuclasses/Block/Html/Topmenu.php

I have created a config.xml here: /app/code/local/Coffeesh0p/Topmenuclasses/etc/config.xml

config.xml contains the following:

<config>
<modules>
    <Coffeesh0p_Topmenuclasses>
        <version>1.0</version>
    </Coffeesh0p_Topmenuclasses>
</modules>
<global>
    <blocks>
        <page>
            <rewrite>
                <html_topmenu>Coffeesh0p_Topmenuclasses_Block_Html_Topmenu</html_topmenu>
            </rewrite>
        </page>
    </blocks>
</global>

And finally, my new Topmenu.php contains the following:

HTML Test

<?php

class Coffeesh0p_Topmenuclasses_Block_Html_Topmenu extends Mage_Page_Block_Html_Topmenu
{

    public function getHtml($outermostClass = '', $childrenWrapClass = '')
    {

        return "TEST1";

    }

    protected function _getHtml(Varien_Data_Tree_Node $menuTree, $childrenWrapClass)
    {

        return "TEST2";

    }
}

?>

So, why is this file being included but my functions are not being called?

EDIT - I'm using Ultimo theme, and it turns out they use their own menu instead of the default topmenu, so that's why nothing was happening.

Oh well, at least I have learned something about module creation and from the resulting discussion!

Answer 1

I would venture to say that your getHtml method is not being called or you're not issuing echo from the template file:

<?php $_menu = $this->getHtml('level-top') ?>
<?php if($_menu): ?>
<div class="nav-container">
    <ul id="nav">
        <?php echo $_menu ?>
    </ul>
</div>
<?php endif ?>

However, in general you should avoid rewriting the Topmenu classes as it is commonly referred to as 'the most overridden class in Magento'. I typically try to modify it via the Observer that is called immediately after the start of getHtml (~ line 71 in CE 1.8):

Mage::dispatchEvent('page_block_html_topmenu_gethtml_before', array(
    'menu' => $this->_menu,
    'block' => $this
));

This returns the block to you, which allows you to make your modifications as you see fit. If you're looking to affect the actual nesting or add classes to the topmenu tags I understand the challenge, especially with the concatenation of the li/span tags, but you can probably affect this by modifying in-place the method _getMenuItemAttributes, others.