Magento : Display product count in Subcategory menu

Magento is the most popular use for ecommerce solutions in the web, because there have already useful built in functions and modules such a newsletter sending, credit card payments, strong securities and more and make life easy as a magento developer. In some our work projects, we need to add extra functionally in Magento Store, such a creating custom magento modules, creating custom widgets, add custom pages. In this tutorial, I would like to share on how get the count of products in Subcategories in navigation and append the count in sub category name. In the screenshot below, we appended the count of products in corresponding subcategories, this is very easy to add. This works in Magento Community Edition 1.7.0.2. However if Magento Community release the new version 1.8.x and up, I will update this post and test the compatibility of the module.

What will you do is go to the core directory '\app\code\core\Mage\Page\Block\Html\Topmenu.php' and copy the Topmenu.php, and create a override copy in local folder like '\app\code\local\Mage\Page\Block\Html\Topmenu.php' and modify it. The Modify code shown below.

<?php

class Mage_Page_Block_Html_Topmenu extends Mage_Core_Block_Template {
    /**
     * Top menu data tree
     *
     * @var Varien_Data_Tree_Node
     */
    protected $_menu;

    /**
     * Init top menu tree structure
     */
    public function _construct()
    {
        $this->_menu = new Varien_Data_Tree_Node(array(), 'root', new Varien_Data_Tree());
    }

    /**
     * Get top menu html
     *
     * @param string $outermostClass
     * @param string $childrenWrapClass
     * @return string
     */
    public function getHtml($outermostClass = '', $childrenWrapClass = '')
    {
        Mage::dispatchEvent('page_block_html_topmenu_gethtml_before', array(
            'menu' => $this->_menu
        ));

        $this->_menu->setOutermostClass($outermostClass);
        $this->_menu->setChildrenWrapClass($childrenWrapClass);

        $html = $this->_getHtml($this->_menu, $childrenWrapClass);

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

        return $html;
    }

    /**
     * Recursively generates top menu html from data that is specified in $menuTree
     *
     * @param Varien_Data_Tree_Node $menuTree
     * @param string $childrenWrapClass
     * @return string
     */
    protected function _getHtml(Varien_Data_Tree_Node $menuTree, $childrenWrapClass)
    {
        $html = '';

        $children = $menuTree->getChildren();
        $parentLevel = $menuTree->getLevel();
        $childLevel = is_null($parentLevel) ? 0 : $parentLevel + 1;

        $counter = 1;
        $childrenCount = $children->count();

        $parentPositionClass = $menuTree->getPositionClass();
        $itemPositionClassPrefix = $parentPositionClass ? $parentPositionClass . '-' : 'nav-';

        foreach ($children as $child) {

            $child->setLevel($childLevel);
            $child->setIsFirst($counter == 1);
            $child->setIsLast($counter == $childrenCount);
            $child->setPositionClass($itemPositionClassPrefix . $counter);

            $outermostClassCode = '';
            $outermostClass = $menuTree->getOutermostClass();

            if ($childLevel == 0 && $outermostClass) {
                $outermostClassCode = ' class="' . $outermostClass . '" ';
                $child->setClass($outermostClass);
            }

   /* custom code */
   $category = Mage::getModel('catalog/category')->load(str_replace('category-node-', '', $child->getId()));
   $prodCollection = Mage::getResourceModel('catalog/product_collection')->addCategoryFilter($category);
            /* cuatom code end */

   $html .= '<li ' . $this->_getRenderedMenuItemAttributes($child) . '>';

   /* original */
   // $html .= '<a href="' . $child->getUrl() . '" ' . $outermostClassCode . '><span>' . $this->escapeHtml($child->getName()) . '</span></a>';

   /* custom count products */
   $html .= '<a href="' . $child->getUrl() . '" ' . $outermostClassCode . '><span>' . $this->escapeHtml($child->getName()) . (is_null($parentLevel) ? '' : ' ('.$prodCollection->count().')') . '</span>' . '</a>';

            if ($child->hasChildren()) {
                if (!empty($childrenWrapClass)) {
                    $html .= '<div class="' . $childrenWrapClass . '">';
                }
                $html .= '<ul class="level' . $childLevel . '">';
                $html .=  $this->_getHtml($child , $childrenWrapClass);
                $html .= '</ul>';

                if (!empty($childrenWrapClass)) {
                    $html .= '</div>';
                }
            }
            $html .= '</li>';

            $counter++;
        }

        return $html;
    }

    /**
     * Generates string with all attributes that should be present in menu item element
     *
     * @param Varien_Data_Tree_Node $item
     * @return string
     */
    protected function _getRenderedMenuItemAttributes(Varien_Data_Tree_Node $item)
    {
        $html = '';
        $attributes = $this->_getMenuItemAttributes($item);

        foreach ($attributes as $attributeName => $attributeValue) {
            $html .= ' ' . $attributeName . '="' . str_replace('"', '\"', $attributeValue) . '"';
        }

        return $html;
    }

    /**
     * Returns array of menu item's attributes
     *
     * @param Varien_Data_Tree_Node $item
     * @return array
     */
    protected function _getMenuItemAttributes(Varien_Data_Tree_Node $item)
    {
        $menuItemClasses = $this->_getMenuItemClasses($item);
        $attributes = array(
            'class' => implode(' ', $menuItemClasses)
        );

        return $attributes;
    }

    /**
     * Returns array of menu item's classes
     *
     * @param Varien_Data_Tree_Node $item
     * @return array
     */
    protected function _getMenuItemClasses(Varien_Data_Tree_Node $item)
    {
        $classes = array();

        $classes[] = 'level' . $item->getLevel();
        $classes[] = $item->getPositionClass();

        if ($item->getIsFirst()) {
            $classes[] = 'first';
        }

        if ($item->getIsActive()) {
            $classes[] = 'active';
        }

        if ($item->getIsLast()) {
            $classes[] = 'last';
        }

        if ($item->getClass()) {
            $classes[] = $item->getClass();
        }

        if ($item->hasChildren()) {
            $classes[] = 'parent';
        }

        return $classes;
    }
}