Custom category menu navigation in Magento

Magento has its top menu reserved for category navigation. It’s pretty solid for displaying categories, even when there is a large number of them.

The layout

Open app/design/frontend/base/default/layout/page.xml or your theme’s equivalent.
Place the following code under default tag:

<reference name="right">

     <block type="core/template" name="catalog.sidenav" template="page/custom.phtml" before="cart_sidebar"/>

</reference>

This will tell Magento to load our template on each page that supports a layout with a right column.

Now, let’s create our template file.

The template

What we need to do is go through all of the store’s categories, get their subcategories (2nd level), sub-subcategories (3rd level) and display them. In the process we need to look for a case when the ID of the category in our list matches the ID of a current category. When we find it – we’ll make it bold.

Create app/design/frontend/base/default/template/page/custom.phtml with the following content:

<ul>

    <?php

        $obj = new Mage_Catalog_Block_Navigation();

        $storeCategories = $obj->getStoreCategories();

        Mage::registry('current_category') ? $currentCategoryId = Mage::registry('current_category')->getId() : $currentCategoryId='';

        foreach ($storeCategories as $_category):

    ?>

            <li>

                <strong><?php echo $_category->getName(); ?></strong>

                <?php $categoryChildren = $_category->getChildren(); ?>

                <?php if($categoryChildren->count()) : ?>

                    <ul>

                        <?php foreach($categoryChildren as $_categoryChild) : ?>

                            <?php $_categoryChildModel = Mage::getModel('catalog/category')->load($_categoryChild->getId());?>

                            <?php $categoryGrandchildren=$_categoryChild->getChildren(); ?>

                            <li>

                                <?php

                                    $currentCategoryId===$_categoryChild->getId() ? $bold="style=\"font-weight:bold\"" : $bold='';

                                    echo '&emsp;' . '<a href="' . $_categoryChildModel->getUrl() . '"' . $bold . '>' .  $_categoryChild->getName() . '(' . $_categoryChildModel->getProductCollection()->count() . ')</a>';

                                ?>

                            </li>

                            <?php if($categoryGrandchildren->count()) : ?>

                                <?php foreach($categoryGrandchildren as $_categoryGrandchild) : ?>

                                    <?php $_categoryGrandchildModel = Mage::getModel('catalog/category')->load($_categoryGrandchild->getId());?>

                                    <li>

                                        <?php

                                            $currentCategoryId===$_categoryChild->getId() ? $bold="style=\"font-weight:bold\"" : $bold='';

                                            echo '&emsp;&emsp;' . '<a href="' . $_categoryGrandchildModel->getUrl() . '"' . $bold . '>' .  $_categoryGrandchild->getName() . '(' . $_categoryGrandchildModel->getProductCount() . ')</a>';

                                        ?>

                                    </li>

                                <?php endforeach; ?>

                            <?php endif; ?>

                        <?php endforeach; ?>

                    </ul>

                <?php endif; ?>

            </li>

        <?php endforeach ?>

</ul>

You can also insert this template to any other page by coding a layout update or via admin, by inserting this line as content of your CMS page:

{{block type="core/template" template="page/custom.phtml"}}