Our site (Joomla 2.5.8) is using the Document Seller component/module (I'm not clear on the proper use of these terms in the Joomlaverse) to categorize and sell a series of PDF documents. The categorization is currently problematic.
The structure is such that there are a small number of categories (about 5) each of which has 3-8 sub-categories. Documents belong to an arbitrary number of subcategories. (The business logic doesn't enforce a constraint of documents only belonging to subcategories, but that's how it's been used.)
The database tables look like you'd expect: a categories table which includes a parent ID (that's how the subcategories are linked to their parent categories) and a category/document join table with IDs for categories. Looking at the database tables this all seems to be in order.
However, when I visit the listing page for a subcategory, I see a path like this:
http://www.oursite.org/index.php/publications/strategic-planning/subcategory-name
...and breadcrumbs like this:
Home » Publications » Strategic Planning » Subcategory Name » Strategic Planning » Subcategory Name
The first link to "Subcategory Name" has the URL which shows in the location bar of the browser. The second link to "Strategic Planning" looks like this:
http://www.oursite.org/index.php/publications/strategic-planning/subcategory-name/view_categories/9-strategic-planning
The page reads "There are no documents in this category" although there are, in fact, documents in this category. If I visit the category URL listed above, I get a list of subcategories which shows the correct number of documents in the subcategories, but the links there send me back where I was (the page with no documents).
To me it looks like the "proper" (shorter) URL is getting routed to a some set of bogus parameters, and the correct parameters are generating a bogus URL (which gets somehow redirected to the shorter URL).
The router.php
file for the module appears to my inexperienced eye to be in order.
In the administration pages, all the categories show 0 documents, but the documents are in place and, as I've mentioned, the database table linking categories and documents seems to make the correct relationships.
I'm not a Joomla dev, nor a PHP hacker. I'm a Ruby/Rails dev trying to help out our webmaster, who is a non-programmer. How should I get started debugging this problem?