List Hierarchical Term List with Count with Related Term

Question

What I have are custom posts (of a custom post type, wps_business) that have two taxonomies (wps_location & wps_type), and I would like to list all the terms from type of a specific location.

For example:

• POST 1: King's English Cafe, location: London, type: Restaurant (parent), English
• POST 2: La Madeline, location: Paris, type Restaurant (parent), French
• POST 3: Uncle Julios, location: London, type: Restaurant (parent), Mexican
• POST 4: San Marinos, location: London, type: Restaurant (parent), Italian
• POST 5: Chipotle, location: London, type: Restaurant (parent), Mexican
• POST 6: Olive Garden, location: London, type: Restaurant (parent), Italian
• POST 7: Home Depot, location: London, type: Home & Garden (parent), [no-child]
• POST 8: Lowe's, location: London, type: Home & Garden (parent), [no-child]
• POST 9: Frank's Car, location: London, type: Local (parent), Mechanic
• POST 10: Smith's Car, location: London, type: Local (parent), Mechanic
• POST 11: King's Bank, location: London, type: Local (parent), Bank

..etc..

So what I would like to is have a display on the location London page is just a list of terms from type that have posts associated with location London (taxonomy: location). So...

Home & Garden (2)

Local (3)

• Mechanic (2)
• Bank (1)

Restaurant (5)

• English (1)
• Mexican (2)
• Italian (2)

I was thinking that I needed to customize Walker_Category class; however, I believe that a more complex query may be needed. I'd rather not fetch all posts and cycle through to create this. Suggestions? Is there a SQL that will fetch these?

Answer 1

I've done something like this in the Query Multiple Taxonomies plugin:

https://github.com/scribu/wp-query-multiple-taxonomies/blob/master/core.php

The good news is that it's a generic solution: it works for any combination of posts and taxonomies.

The bad news is that it might take some effort to figure out how it's done.