Magento 1.9.2.4 – Price Filter Not Displaying

As you already know the real category filtering is taking place in app/code/core/Mage/Catalog/Model/Layer/Filter/Category.php, more specifically in _getItemsData(). Let us inspect that method.

<?php
            $categoty   = $this->getCategory();
            $categories = $categoty->getChildrenCategories();

            $this->getLayer()->getProductCollection()
                ->addCountToCategories($categories);

            $data = array();

            foreach ($categories as $category) {
                if ($category->getIsActive() && $category->getProductCount()) {
                    $data[] = array(
                        'label' => Mage::helper('core')->escapeHtml($category->getName()),
                        'value' => $category->getId(),
                        'count' => $category->getProductCount(),
                    );
                }
            }

As you can see, the method loads child categories of $categoty in layered navigation filter. That means we need to set this variable to a parent category in level 2 (Every main categories lies in level 2), according to the current category that we stands.

We can achieve this in many ways. In my method, I dig into the codes further and find the exact position where the category is set for layered navigation.

It resides here app/code/core/Mage/Catalog/Model/Layer.php in getCurrentCategory(). The method look like this.

<?php
 public function getCurrentCategory()
{
    $category = $this->getData('current_category');
    if (is_null($category)) {
        if ($category = Mage::registry('current_category')) {
            $this->setData('current_category', $category);
        }
        else {
            $category = Mage::getModel('catalog/category')->load($this->getCurrentStore()->getRootCategoryId());
            $this->setData('current_category', $category);
        }
    }

    return $category;
}

In short, it loads the current category to the variable $categoty (variable that I mentioned in _getItemsData()) if it set, otherwise loads the root-category to variable categoty. Replace this method with this code

<?php
/**
 * Retrieve current category model
 * If no category found in registry, the root will be taken
 *
 * @return Mage_Catalog_Model_Category
 */
public function getCurrentCategory()
{
    $category = $this->getData('current_category');

    if (is_null($category)) {
        $category = Mage::registry('current_category');
        if ($category) {
            /*
             * Check whether the current category is in level 2.
             * If yes set it as current category.
             * Else check for any parent categories with level 2
             */
            if($category->getLevel() != 2) {
                //gets all parent categories
                $parentCategories = Mage::registry('current_category')->getParentCategories();
                /*
                 * If parent categories exist,search for parent categories in level 2.
                 * If exist set it as current category.
                 *else set root category as current category.
                */
                if(count($parentCategories) > 0)
                {
                    foreach ( $parentCategories as $parentCategory ) {
                        if($parentCategory->getLevel() == 2 ) {
                            $category = Mage::getModel('catalog/category')->load($parentCategory->getId());
                            $this->setData('current_category', $category);
                            break;
                        }
                    }
                }
                else {

                    $category = Mage::getModel('catalog/category')->load($this->getCurrentStore()->getRootCategoryId());
                    $this->setData('current_category', $category);
                }
            }
            else {

                $this->setData('current_category', $category);
            }
        }
        else {

            $category = Mage::getModel('catalog/category')->load($this->getCurrentStore()->getRootCategoryId());
            $this->setData('current_category', $category);
        }
    }

    return $category;
}

What we are doing here is, we get the parent category in level 2 from the current category and set it to $categoty, so that we can see all child categories in layered navigation.

As I already mentioned, you can achieve it in many ways. All you need to do is to set $categoty variable with parent category in level 2. Above I have altered the root files. It is not a good practice. You have to create a module that rewrites the model file app/code/core/Mage/Catalog/Model/Layer.php and then overwrite the method getCurrentCategory().

Hope it helps

Price filter uses a bit different SQL query. It tries to avoid joining with the product entity table and replace it with the price index.

As you are using layered navigation module, you need to modify class app\code\local\Amasty\Shopby\Model\Mysql4\Price.php instead of the magento default.