How to add layered Navigation filter as stock availability?

Question

I want to add "Stock availability" as layered navigation filter. but i cant find this attribute in attribute set.

Here Display two option under stock availability if i am select out of stock so display only out of stock product and same as in stock product.

Answer 1

Please see this module on github: https://github.com/tzyganu/stock-filter

"The extension adds a new filter in the layered navigation with 2 options: In stock and out of stock. This way the user can filter only in stock products. The extension can be used only if your store displays out of stock products. It makes no sense otherwise."

The extension was tested on Magento CE 1.7, 1.8 and 1.9 but it probably works on other versions.