Magento Sort Collection By Product Attribute Value Count

Question

I'm currently working on a Magento site which uses layered navigation and a large number of custom attributes for its navigation. What I am looking to do is to add a new "Sort By" option into the listing (selected by default for certain categories) which should help to improve the relevance of the products displayed for a large number of customers.

The site is selling knitting yarn.

Here's how the client would like it to work -

• We have a custom attribute set up called "colour_name" with values such as red, green, yellow, purple etc.

• Due to the nature of the product, sometimes this classification can be somewhat ambiguous, so many products are listed under multiple categories, for example, a bluey-green yarn will have both the "blue" and "green" options selected.

• If a customer selects "blue" from the layered navigation, we would like the products with just the blue option selected to be listed first, followed by products with 2 colours, then 3, and so on.

I don't have a huge amount of experience with collections, however I am familiar with basic sorting and filtering. The collection we need to work with is in app/design/frontend/default/[template_name]/template/catalog/product/list.phtml on the following line:

<?php $_productCollection=$this->getLoadedProductCollection() ?>

I'm not sure whether to perform this sort in the list.phtml file or further down in the helper for categories / sorting.

Unfortunately the site isn't live yet so I can't show you an example, hopefully the description is sufficient but please feel free to ask for clarification on any points if needed.

Answer 1

You may filter and sort collections in Magento via the addAttributeToFilter ( addFieldToFilter for collections other than a productCollection) and addAttributeToSort .

By default, Magento , uses 'ORDER BY' in the underlying SQL for the sort, you should thereby use an approach that uses a custom module with a custom sort on a loaded collection.

There is a very could answer here if you'd like to try that.