Question

We have a category structure like this:
Root
— Category 1
—- Category 1 – 1
——- Category 1 – 1 – 1
——- Category 1 – 1 – 2
—- Category 1 – 2
— Category 2
—- Category 2 – 1
—- Category 2 – 2

Normally, when a user clicks the root category, it appears as empty. Also Category 1 and 2 are empty (by mistake, it could be, that 1 or 2 products are there).

I want, that when a category is clicked, the products of all subcategories (and subcategories’ subcategories) are shown (+ the products which are in the category itself).

We cannot use is_anchor, as this behaviour is only for one of three storeviews and is_anchor is global.

My idea would be to rewrite Mage_Catalog_Block_Product_List, so it returns subcategories’ products when requesting a category but isn’t there a simpler approach by adding a filter or so to all category-collection-requests?

Answers to similar questions are incomplete or use is_anchor.

Answer 1

I solved the problem now on my own.

I created a module which rewrites Mage_Catalog_Model_Category::getProductCollection()

The steps are as follows:

1. When there are no child categories, return the standard parent::getProductCollection()
2. When there are child categories, get all children categories’ ids and save them as an array.
3. Add the current categories’ id to the array.
4. Fetch a collection of all these categories and filter them by is_active.
5. Iterate through the category-collection and load every single category.
6. Get the product collection of every category and iterate through it, saving all product ids to an array. Append to the array when the next category gets loaded.
7. Build a product collection and add a filter with ->addAttributeToFilter('entity_id', array('in' => array_unique($result)));
8. Return the collection. It holds all products of all subcategories and the current categories’ products, as desired (and it has no duplicates in it).