Implement a configurable filter system that can alter the facet's render array prior to being passing to the widget

The issue posted at #830806: Halt date facet drilldown when only one result left is separate, but related.

Thanks for your post, Patrick.

I understand where you are coming from, but I don't agree. Let's look at the following use case. I have two content types, wiki and blog that share the "Tags" vocabulary. I have three enabled facets, "Content type", "Post date", and "Tags". I narrow down "Content type" and "Post date" so that there is only one tag available.

In the scenario you propose, the "Tags" facet would now be hidden. I think this is valuable information for the user to have. Furthermore, I want to have the option to activate the term so that when I deactivate one of the other facets we are still filtering by that term. What happens if the "Tags" facet is hidden, I deactivate a date or content type, and then the taxonomy term I wanted falls out of view because more terms are now available? Now I have to hunt for it, which is not a good thing.

If you do want this functionality, I would suggest looking at hook_facetapi_facets_alter(). The $build array is the render array for all facets, and you will have all the information you need to manipulate the render array to hide the facets. If you want a more reusable solution, you could also create a widget that extends FacetapiWidgetLinks and overrides FacetapiWidgetLinks::buildListItems() to hide items that won't further refine the result set.

Patrick,

Not rash at all! All ideas are more than welcome, and I am glad you raised this. I definitely do not have all the answers, and the issue queue is a great place to vet this stuff out to make sure what gets added in the module makes the most sense to as many people as possible.

Since this is something you want to do, I want to make sure the module is at least flexible enough to support this. Although I don't see adding the option to the core module, there should be a simple way to provide this functionality that could even be a cool UI contrib project that might contain some other interesting tweaks (want to maintain a small module ;-)). As I have time I will play around with this, but feel free to post your findings to this thread of any shortcomings prevent you from doing it.

Thanks again for the ideas,
Chris

P.S. Want to maintain a small module? ;-)

Respectfully marking as "works as designed".

Re-opening based on the feedback from issue #1216034: The "Current search" block (sometimes) shows IDs instead of labels. Would like to see some patches for this as there seems to be specific use cases that people are trying to achieve.

Forgot to mark as active...

I suck.

Thanks for posting your ideas. To me, I see various "facet filters" based on what you are describing. I think adding an API to filter facets by various criteria and adding a couple to core should do the trick. I want to leave some room for people to contribute as well. Maybe even exposing the API and having the implementations live in Search API would be a good idea as well. Anyways, always up for new ideas and different approaches.

Related issue at #1178568: Remove hook_facetapi_facets_alter() and impement another altering method.

Marking as duplicate of #1156606: Implement a configurable filter system that can alter the facet's render array prior to being passing to the widget. The filter system will allow for this functionality, and progress will be tracked in that thread.

See the list at http://drupal.org/node/1156606#comment-4725960 for what will be supported in core Facet API.

Clearly had too many windows open. Posted this to the wrong issue.

Webchick says jump, I say "how high?". http://www.webchick.net/node/89

Changing title to reflect what this task has become.

Also, I pushed the filters branch I was working on locally so people can follow my progress on this. Assigning to myself since this a significant API addition.

The following threads have been marked as duplicates of this one:
#830806: Halt date facet drilldown when only one result left
#1178568: Remove hook_facetapi_facets_alter() and impement another altering method

Here is my progress so far, just a diff from the "filters" and "7.x-1.x" branch. Marking as needs work because the depth filter is broken and the default system needs to be re-tooled. However, it gives an overview of how the system could work. There is a new "filters" configuration form to apply filters in a certain order. The filter is applied after the results are returned from the server and before the widget plugin is executed, so ultimately it the render to make customizations prior to being passed to the widget.

The system has been committed at 905ade9.

I opened two new issues for some of the suggestions above because they are more complex when taking hierarchical facets into account. I am looking for contributions to get them into the module.

#1234902: Implement filter "Don't show blocks with only 1 (or X) items"
#1234894: Implement filter "Don't show items that won't narrow down the results"

All additional filter plugin requests should be tagged with filter plugin.