I installed this contribution following Sam's response on this thread, but I'm not sure whether I've understood how to use it correctly, or whether I haven't explained what I was after very well.
I don't want to search categories as such. I want to search by product field, either across all categories or by category. The product database contains text fields describing various plant characteristics and I want to be able to limit searches to specific fields. eg. if I'm wanting flower colour=red then I don't want foliage colour=red in the search results. If I'm wanting to find plants that thrive in chalky soils, I don't want the results containing plants that can't grow in chalk. So I need a filter for linking a search term, eg. red or chalk, to a specific field, eg. flower colour or soil type, and giving results only where the field products_flower_colour contains 'red' and the field products_soil_type contains 'challk'.
Does this contribution do that? Or can it be easily modified to do that? At the moment, if I click the search categories check box, which is the only visible addition to the advanced search page, then I just get the results "There is no category that matches the search criteria."