Channel:categories of entries that have category from different category group

Question

What we are trying to do:
I am using three category-groups, "product category", brands and country of origin, to create a navigation in a shop with the ability to filter the content of each product category with a specific brand or country.

The product category group is used to generate the main navigation and when a category is selected a listing-page is displayed with the entries of that category.

The display page in turn shows a "sub-nav" of the different brands and countries of origins.

Structure of the product category group:

Main category 1
    sub-category 1
    sub-category 2
Main category 2
    sub-category 3

When i pick a sub-category my url looks like this:

domain.com/products/[sub-category]

This page should show all products in this category and possible 3rd levels of product groups in the top and then brands and countries in a sub-nav.

It should look a little like this:

3rd lvl sub-category
-
Brands
    Brand 2
    Brand 5
Countries of origin
    Country 1
    Country 3

Where Brand 1/3/4 and Country 2 are not shown since no product with the [sub-category] has them selected.

When i select a brand or country that segment is added to the url and {segment_category_ids} gives me all the matched categories for use in the {exp:channel:entries} tag.

This is where i am having some problems..
I cant get my head around how to display only the brands and countries that have entries in the already selected [sub-category].

By default it displays every category that is used by any entry in the products channel. We haven't used categories all that much so i am not sure that i am going at it the right way.

I have tried to create a list of all the entry_id's from the subset and use those pipe-separated in the show-parameter of the {exp:channel:categories} tag-pair but i haven't gotten it to work yet.

We have mostly been using Playa for relations between different entries and "pages" before but i thought i could be good to get a grip on how to do it natively.

Does anyone have a better approach or any ideas on what i should do?

Answer 1

I don't think you can achieve this result with pure EE,but if you don't mind using some php, you could do something along these lines:

This runs through you entries ( it's a dynamic ee tag, so if your product category is defined in the url, it should only show the entries in that category ) and adds their categories to an array in PHP.

<?php $categories = array(); $i = 0; ?>
{exp:channel:entries channel="products"}
    {categories}
       <?php
           if(!in_array("{category_url_title}", $categories)){
               $categories[$i][0] = "{category_id}";
               $categories[$i][1] = "{category_name}";
               $categories[$i][2] = "{category_url_title}";
               $i++;
           }
       ?>
    {/categories}
{/exp:channel:entries}

You can use this PHP array to output the categories. This array should only contain the categories that have entries which are in the product-category of the page you're on.

It might very well be that there's a much easier, and especially cleaner, way to achieve this result though.. but it should work. :)

Answer 2

We handle this by placing the categories in the URL as segments (example.com/store/category_foo/category_bar), and use the seg2cat add-on, which will give you a {segment_category_ids} variable, which can be used like this:

{exp:channel:entries category="{segment_category_ids}" dynamic="no"}

This will give you the ability to handle multiple category id's in the URL, which I believe might be part of the problem you're trying to solve.

Answer 3

So my approach to this sort of thing is to use Low's seg2cat extension. As the name suggests, this lets you get from a url segment to a category_id/name etc.

Hence if your URL is http://example.com/fruit/apples, then {segment_2_category_id} will be the category_id of your "fruit" category.

You can then push this into your channel:entries tag:

{exp:channel:entries
  channel="brands"
  category="{segment_2_category_id}"
  dynamic="no"
}
  <li>{title}</li>
{/exp:channel:entries}

Extra tip: If you need this to work with a fallback category (when no cat in the URL) you can take advantage of the parse order and the way preload_replace works to do something like this:

{if segment_2_category_id}
  {preload_replace:pre_current_category="{segment_2_category_id}"}
{/if}
{preload_replace:pre_current_category="n"}

{exp:channel:entries
  channel="brands"
  category="{pre_current_cat}"
  dynamic="no"
}
  <li>{title}</li>
{/exp:channel:entries}

As attempts to redefine a preload_replace are ignored and the first value used, and simple conditionals are parsed before preload_replaces.

Answer 4

It looks like you've got your navigation working how you want but it's displaying categories and sub-categories that's the problem? GWCode Categories Addon: http://gwcode.com/add-ons/gwcode-categories is excellent for going through a hierarchy of categories.

I'm struggling a bit with your question. With your actual category groups and an example layout I'd be able to offer some code as well.

Answer 5

Kim,

Can you share your PHP solution with me that apparently solved your issue> I'm running into a similar situation with multiple categories to filter on. I'm a PHP newbe....