Filtered conditions on taxonomy - possible cascade issue?

[earthwytch]

I have the following form field, populated using a taxonomy. I am trying to use a filtering condition to only include taxonomy terms that are set to a particular provider_type (another taxonomy term selected specifically for this page).

<label for="provider_categories" class="block text-sm font-medium text-gray-700">Category:</label>
<select id="provider_categories" name="provider_categories" class="mt-4 border py-2 px-4 mb-2 border-fp-blue bg-white rounded-t rounded-b w-full text-base text-fp-blue-medium" data-comparison="=" data-include-null="0">
  <option value="">All</option>
  {{ taxonomy:provider_categories provider_types:in="{ selected_provider_type:slug }" | sort  }}
    <option value="{{ slug }}" {{ if get:provider_categories == slug }}selected{{ /if }}>{{ title }}</option>
   {{ /taxonomy:provider_categories }}
</select>

Here is an example provider_category taxonomy term:

title: Bedroom
blueprint: provider_category
provider_types:
  - equipment-supplier

Here is a snippet from the page entry, containing the selected_provider_type for that page:

---
...
enable_speech: true
search_heading: 'Search for equipment suppliers'
info_banner_media_type: none
selected_provider_type: equipment-supplier
keyword_search: true
category_search: true
...
---

Here is a snippet showing how the selected_provider_type field is created in the blueprint:

...
          -
            handle: selected_provider_type
            field:
              create: false
              taxonomies:
                - provider_types
              type: terms
              display: 'Selected provider type'
              instructions: 'Select the provider types to display on this page.'
              max_items: 1
              mode: select
...

If I use text instead of a variable value in the condition, such as {{ taxonomy:provider_categories provider_types:in="equipment-supplier" | sort }} it also does not work, incorrectly showing the current page title ("Find an equipment supplier") as the only value in the select. This makes me think it isn't anything to do with the variable.

If I change the filter to use any other field, something like {{ taxonomy:provider_categories slug:contains="co" | sort }} or {{ taxonomy:provider_categories title:is="Furniture" | sort }}, then it works correctly.

Do I have some sort of cascade issue? Or am I using the filters incorrectly?

[edalzell]

can you remove this | sort to make sure? That syntax is incorrect anyway, that's the syntax for calling a modifier, but you're in a tag.

[earthwytch]

Hi there, removing the | sort hasn't changed the result.

[JohnathonKoster]

If there are no results, the inner contents of most tags will still get evaluated to allow you the opportunity to handle the "no results" scenario; it sounds like this is what you are running into.

If you add a {{ dump }} tag here:

<label for="provider_categories" class="block text-sm font-medium text-gray-700">Category:</label>
<select id="provider_categories" name="provider_categories" class="mt-4 border py-2 px-4 mb-2 border-fp-blue bg-white rounded-t rounded-b w-full text-base text-fp-blue-medium" data-comparison="=" data-include-null="0">
  <option value="">All</option>
  {{ taxonomy:provider_categories provider_types:in="{ selected_provider_type:slug }"  }}
    {{ dump }}
    <option value="{{ slug }}" {{ if get:provider_categories == slug }}selected{{ /if }}>{{ title }}</option>
   {{ /taxonomy:provider_categories }}
</select>

You will likely see a variable named no_results set to true.

We can use this to conditionally render the inner contents:

<label for="provider_categories" class="block text-sm font-medium text-gray-700">Category:</label>
<select id="provider_categories" name="provider_categories" class="mt-4 border py-2 px-4 mb-2 border-fp-blue bg-white rounded-t rounded-b w-full text-base text-fp-blue-medium" data-comparison="=" data-include-null="0">
  <option value="">All</option>
  {{ taxonomy:provider_categories provider_types:in="{ selected_provider_type:slug }"  }}
    {{ unless no_results }}
        <option value="{{ slug }}" {{ if get:provider_categories == slug }}selected{{ /if }}>{{ title }}</option>
    {{ /unless }}
   {{ /taxonomy:provider_categories }}
</select>

Alternatively, we can also alias the results using the as="some-alias" parameter. If we do this, the results will get stored in a variable name of our choosing (this would also let you apply your sort, or other modifiers, more easily):

<label for="provider_categories" class="block text-sm font-medium text-gray-700">Category:</label>
<select id="provider_categories" name="provider_categories" class="mt-4 border py-2 px-4 mb-2 border-fp-blue bg-white rounded-t rounded-b w-full text-base text-fp-blue-medium" data-comparison="=" data-include-null="0">
  <option value="">All</option>
  {{ taxonomy:provider_categories provider_types:in="{ selected_provider_type:slug }" as="options"  }}
    {{ options }}
        <option value="{{ slug }}" {{ if get:provider_categories == slug }}selected{{ /if }}>{{ title }}</option>
    {{ /options }}
   {{ /taxonomy:provider_categories }}
</select>

The aliased option is useful if you also wanted to conditionally render the select wrapper, or other custom behavior. The content inside {{ options }} ... {{ /options }} won't get evaluated if the array is empty.

[earthwytch]

Thanks, that is actually really helpful to understand that what I'm seeing is the effect of no results 😎 I guess my issue now is why I am getting no results for "provider_categories" that have a taxonomy term of "equipment-supplier". I feel like I'm missing something really basic 🤔

/content/taxonomies/provider_categories/daily-living.yaml

title: 'Daily living'
blueprint: provider_category
provider_types:
  - equipment-supplier

[JohnathonKoster]

I think its related to the provider_types:in filter:

{{ taxonomy:provider_categories provider_types:in="{ selected_provider_type:slug }" }}

Does it work if you switch it to "contains"? That way it should check if the provider type has the slug you're looking for:

{{ taxonomy:provider_categories provider_types:contains="{ selected_provider_type:slug }" }}
    ...
{{ /taxonomy:provider_categories }}

[earthwytch]

YUSS! Thank you 🌞 That worked perfectly.

[edalzell]

and you could tidy it up further like :provider_types:contains="selected_provider_type:slug"

[earthwytch]

Ahhhh beautiful! Combining it all together allows me to elegantly hide the category drop-down if there are no matching terms as well. Magical, thank you 💃🏼

<!-- category drop-down -->
{{ taxonomy:provider_categories :provider_types:contains="selected_provider_type:slug" as="options" }}
  {{ unless no_results }}
    <label for="provider_categories" class="block text-sm font-medium text-gray-700">Category:</label>
    <select id="provider_categories" name="provider_categories" class="mt-4 border py-2 px-4 mb-2 border-fp-blue bg-white rounded-t rounded-b w-full text-base text-fp-blue-medium" data-comparison="=" data-include-null="0">
      <option value="">All</option>
      {{ options }}
        <option value="{{ slug }}" {{ if get:provider_categories == slug }}selected{{ /if }}>{{ title }}</option>
      {{ /options }}                                
    </select>
   {{ /unless }}
{{ /taxonomy:provider_categories }}