Remove empty categories from magento menu - php

Question

I want my main menu to not include any categories that are empty. I've done this for the layered navigation very easily in the relevant phtml file by using
$_category->getProductCount()
However, for the navigation menu, I'm finding it impossible to do this as easily (I have seen the Prattski example but it does seem rather OTT).
The main menu seems to be built in Mage_Page_Block_Html_Topmenu.php, specifically in the function _getHtml. This gets all the children in the menu and if I try something like $child->getId(), I get something like "category-node-36".
It doesn't seem like I'm too far from being able to use getProductCount() and so test if it's more than zero.
Is it possible to do this? Can somebody point me to how?
If I can, I'll extend the class with my version.

Answer 1

To do this, go to:
app/code/core/Mage/Catalog/Block Folder and copy Navigation.php and override it in your local package.
Open Navigation.php of your package and paste below code in this file:
if ($category->getIsActive()) {
$cat = Mage::getModel('catalog/category')->load($category->getId());
$products = Mage::getResourceModel('catalog/product_collection')->addCategoryFilter($cat);
Mage::getSingleton('catalog/product_status')->addVisibleFilterToCollection($products);
Mage::getSingleton('catalog/product_visibility')->addVisibleInCatalogFilterToCollection($products);
Mage::getSingleton('cataloginventory/stock')->addInStockFilterToCollection($products);
if(count($products)==0)
return;
}
I hope my code will help you.

Answer 2

I finally cracked it although I'm far from convinced it's an optimum solution. Anyway, I'll described what I did here and hopefully somebody can make it more efficient. I'll give a blow-by-blow description as I was ufamiliar with quite a few areas. So apologies for the length.
As I said, in my case at least, the main menu is built via Topmenu.php in app/code/core/Mage/Page/Block/Html, specifically the method _getHtml. I very definitely don't want to modify a core file so I found out how to extend this method via a new module. (You can skip this bit if you're familiar with creating new modules.)
Configuring a new module
I needed to create a new module (I'll call it MYMOD below). As I'm overwriting the core magento page block, I had to create new folders: app/code/local/MYMOD/Page and in there two sub-folders, Block and etc (I believe they are case sensitive). And within Block another subfolder Html. You can see this is exactly mirroring the folder structure from app/code/core/Mage.
The etc folder holds the specification for the new module in a config.xml file. This is what mine looks like:
<?xml version="1.0" encoding="UTF-8"?>
<!-- The root node for Magento module configuration -->
<config>
<!--
The module's node contains basic
information about each Magento module
-->
<modules>
<!--
This must exactly match the namespace and module's folder
names, with directory separators replaced by underscores
-->
<MYMOD_Page>
<!-- The version of our module, starting at 0.0.1 -->
<version>0.0.1</version>
</MYMOD_Page>
</modules>
<global>
<blocks>
<page>
<rewrite>
<html_topmenu>MYMOD_Page_Block_Html_Topmenu</html_topmenu>
</rewrite>
</page>
</blocks>
</global>
</config>
You can find out about the whys and wherefors of this elsewhere.
Unfortunately (in my opinion!), that's not all you have to do to specify a new module in Magento. You also have to create a file called "MYMOD_Page.xml" in app/etc/modules. This is just telling Magento about your module and where to look for it. Mine looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<config>
<modules>
<MYMOD_Page>
<!-- Whether our module is active: true or false -->
<active>true</active>
<!-- Which code pool to use: core, community or local -->
<codePool>local</codePool>
</MYMOD_Page>
</modules>
</config>
OK, sorry for the irrelevant instructions on modules but I do like self-contained blow-by-blow explanations.
Overwriting the method
I can now create a new file in my module with a subclass in which I can have methods (functions) that will be used instead of the core Magento ones. The file name has to be the same as the original file, Topmenu.php and it goes in app/code/local/MYMOD/Page/Block/Html.
Remember, the object oriented structure means that all of the functions in the original core version of Topmenu.php are available to me, I don't have to copy them in my new version (great for maintainability). My version of Topmenu.php only has to contain any new functions I might want (in this case I didn't need any) and redeclare any functions I want to overwite with my own version. In my case, I needed to modify two functions: _getHtml and _getMenuItemClasses.
_getHtml needs additional checks so any empty categories aren't included.
_getMenuItemClasses needs additional checks so that the class "parent" isn't added to categories whose children are empty.
Here's how I did it (with comments). I'm sure there are better ways but I'm still fairly new to Magento.
class MYMOD_Page_Block_Html_Topmenu extends Mage_Page_Block_Html_Topmenu
// Create my subclass, in accordance with how I've defined the new module
{
/**
* 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);
}
/*
* Find out if this category has any products. I don't know an easier way.
* The id of every child returned by getID is of the form "category-node-nnn"
* where nnn is the id that can be used to select the category details.
* substr strips everything leaving just the nnn.
* Then use getModel-> getCollection with a filter on the id. Although this looks
* like it will return many, obviously category ids are unique so in fact it only
* returns the category we're currently looking at.
*/
$_gcategoryId = substr($child->getId(), 14, 6);
$_gcategories = Mage::getModel('catalog/category')->getCollection()->addFieldToFilter('entity_id', array('eq', $_gcategoryId));
foreach ($_gcategories as $_gcategory) {
$_gcategoryCount = $_gcategory->getProductCount();
}
/*
* Now only include those categories that have products.
* In my case I also wanted to include the top level categories come what may.
*/
if (($childLevel == 0) || ($_gcategoryCount > 0)) {
$html .= '<li ' . $this->_getRenderedMenuItemAttributes($child) . '>';
$html .= '<a href="' . $child->getUrl() . '" ' . $outermostClassCode . '><span>'
. $this->escapeHtml($child->getName()) . '</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;
}
/**
* 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()) {
/*
* Don't just check if there are children but, if there are, are they all empty?
* If so, then the changes in _getHtml will mean none of them will be included
* and so this one has no children displayed and so the "parent" class is not appropriate.
*/
$children = $item->getChildren(); // Get all the children from this menu category
foreach ($children as $child) { // Loop over each child and find out how many products (see _getHtml)
$_gcategoryId = substr($child->getId(), 14, 6);
$_gcategories = Mage::getModel('catalog/category')->getCollection()->addFieldToFilter('entity_id', array('eq', $_gcategoryId));
foreach ($_gcategories as $_gcategory) { // Remember, there's actually only one category that will match the child's id
$_gcategoryCount = $_gcategory->getProductCount();
}
if ($_gcategoryCount > 0) { // As soon as one child has products, then we have a parent and can stop looking
$classes[] = 'parent';
break;
}
}
}
return $classes;
}
}
I hope this is clear. It does what I want (my store is small) but any suggestions for improvement welcome.

Answer 3

path: app/design/frontend/rwd/default/template/page/html/topmenu/renderer.phtml
Make this query (it is 0.0004 sec), under the foreach ($children as $child) {
$mageconnection = Mage::getSingleton("core/resource")->getConnection("core_read");
$query="select count(cataloginventory_stock_item.is_in_stock) as subcount,catalog_category_flat_store_1.`name` from catalog_category_flat_store_1 INNER JOIN
catalog_category_product_index on catalog_category_product_index.category_id=catalog_category_flat_store_1.entity_id INNER JOIN
cataloginventory_stock_item on cataloginventory_stock_item.product_id=catalog_category_product_index.product_id
where cataloginventory_stock_item.is_in_stock=1 and catalog_category_product_index.category_id=";
$subCatqueryId = str_replace('category-node-', '', $child->getId());
$prodCollection = $mageconnection->fetchAll("$query'{$subCatqueryId}'");
if($prodCollection[0]["subcount"] > 0) {
$child->setLevel($childLevel);
$child->setIsFirst($counter == 1);
// these are the existing code ..
...
...
$counter++;
}
}
It is very fast and secure way to control product count.