Add option to show current search string in facet summary

I extended the patch from #2979223-57: Add option to show current search string in facet summary → with the fix from 🐛 Facets with ajax enabled and no source path results in /views/ajax?f... urls RTBC

FWIW I'm using this patch on a client site and it's working fine, but the client has requested exploded (individual) search terms rather than the whole search string, so one at a time can be cleared. This may be a use case others have as well. For now as a front-end dev I'm just going to have to go a different route and create the functionality with JS, but might be worth considering this as a config option.

Patch contains deprecated getMasterRequest. Rewritten to getMainRequest.

Created branch 2979223-search-string-summary from 3.0.x and re-rolled the patch from https://www.drupal.org/project/facets/issues/2979223#comment-15146318 ✨ Add option to show current search string in facet summary Needs work

I'm not sure that I should change the version of this issue to 3.0.x-dev, though, so I'll leave that for others to decide.

The reset facets option ("Adds reset facets link") will be shown now as well when a search query is used.

This is marked as NW for 2 years. Why don't we get brave and ask for a review?

It should also see a re-roll for 3.x though, so maybe NW is accurate?

heddn → changed the visibility of the branch 2979223-search-string-summary-v2 to hidden.

heddn → changed the visibility of the branch 3.0.x to hidden.

NW because tests are failing (the first few failures look simple to fix) and phpc/phpstan complaints.

Updated patch

Looks like the auto merge train didn't actually merge this. What more work is needed here?

I tried adding the MR #185 to both 3.0.0 and the 3.0-dev version. The patch applies successfully to both, but when I enable the module and try to add a facet summary to the header region of the view, I run into an error:

"The submitted value in the Facet summary" element is not allowed

I don't see a field for editing. I try to remove it, and it errors out again with the same error. I have to end up closing the popup and canceling my view changes to get rid of the field.

Ok after some review I found a couple issues

1) If there are no facet summary fields created, trying to add one to the view breaks as found in comment #74. Instead, there should be a check for empty facet summaries and show a link to /admin/config/search/facets directing the user to add one.

2) Summary Facet doesn't show current search string when Show a text when there are no results is selected. Unchecking the no results box allows the Show the current search string to appear

3) Adding a facet summary in the views filter criteria runs into a PHP error due to SearchApiDisplay not returning anything when it should return a string. Adding the facet summary in the views header doesn't have this issue. A quick fix for this one is below

/**
   * {@inheritdoc}
   */
  public function getCount(): ?string {
    $search_id = $this->getDisplay()->getPluginId();
    if ($search_id && !empty($search_id)) {
      if ($this->searchApiQueryHelper->getResults($search_id) !== NULL) {
        return $this->searchApiQueryHelper->getResults($search_id)
          ->getResultCount();
      }
    }
    return NULL;
  }