Contextual websearch on tags and categories. DDFFORM-788

Embedding a contextualized version of the editorial search view directly
on 'Categories' and 'Tags' individual term pages.
This allows the user to find content that is associated with this term.

config/sync/pathauto.pattern.category_term.yml

@@ -0,0 +1,22 @@
+uuid: 6d9e0463-1e18-45be-b9cd-9e30b50bdf53
+langcode: en
+status: true
+dependencies:
+  module:
+    - taxonomy
+id: category_term
+label: 'Category term - embedded search'
+type: 'canonical_entities:taxonomy_term'
+pattern: '/search/web/categories/[term:name]'
+selection_criteria:
+  0f0f2190-bf04-4b11-9d33-5404ab1352ef:
+    id: 'entity_bundle:taxonomy_term'
+    negate: false
+    uuid: 0f0f2190-bf04-4b11-9d33-5404ab1352ef
+    context_mapping:
+      taxonomy_term: taxonomy_term
+    bundles:
+      categories: categories
+selection_logic: and
+weight: -5
+relationships: {  }

config/sync/pathauto.pattern.tag_term.yml

@@ -0,0 +1,22 @@
+uuid: 7b51f435-12a6-4a18-8f2b-6421bccf8ea2
+langcode: en
+status: true
+dependencies:
+  module:
+    - taxonomy
+id: tag_term
+label: 'Tag term - embedded search'
+type: 'canonical_entities:taxonomy_term'
+pattern: '/search/web/tag/[term:name]'
+selection_criteria:
+  570dcc15-8a7a-4d87-8d5b-1d56e4290331:
+    id: 'entity_bundle:taxonomy_term'
+    negate: false
+    uuid: 570dcc15-8a7a-4d87-8d5b-1d56e4290331
+    context_mapping:
+      taxonomy_term: taxonomy_term
+    bundles:
+      tags: tags
+selection_logic: and
+weight: -5
+relationships: {  }

config/sync/views.view.editorial_search.yml

@@ -224,6 +224,7 @@ display:
           query_tags: {  }
       relationships: {  }
       use_ajax: true
+      show_admin_links: false
       header: {  }
       footer: {  }
       display_extenders: {  }
@@ -259,3 +260,95 @@ display:
         - 'config:field.storage.node.field_branch'
         - 'config:search_api.index.content_events'
         - 'search_api_list:content_events'
+  term_page:
+    id: term_page
+    display_title: 'Context by tag'
+    display_plugin: block
+    position: 2
+    display_options:
+      arguments:
+        categories:
+          id: categories
+          table: search_api_index_content_events
+          field: categories
+          relationship: none
+          group_type: group
+          admin_label: ''
+          plugin_id: search_api
+          default_action: empty
+          exception:
+            value: all
+            title_enable: false
+            title: All
+          title_enable: false
+          title: ''
+          default_argument_type: fixed
+          default_argument_options:
+            argument: ''
+          summary_options: {  }
+          summary:
+            sort_order: asc
+            number_of_records: 0
+            format: default_summary
+          specify_validation: false
+          validate:
+            type: none
+            fail: 'not found'
+          validate_options: {  }
+          break_phrase: false
+          not: false
+        tags:
+          id: tags
+          table: search_api_index_content_events
+          field: tags
+          relationship: none
+          group_type: group
+          admin_label: ''
+          plugin_id: search_api
+          default_action: empty
+          exception:
+            value: all
+            title_enable: false
+            title: All
+          title_enable: false
+          title: ''
+          default_argument_type: fixed
+          default_argument_options:
+            argument: ''
+          summary_options: {  }
+          summary:
+            sort_order: asc
+            number_of_records: 0
+            format: default_summary
+          specify_validation: false
+          validate:
+            type: none
+            fail: 'not found'
+          validate_options: {  }
+          break_phrase: false
+          not: false
+      filters: {  }
+      filter_groups:
+        operator: AND
+        groups:
+          1: AND
+      defaults:
+        arguments: false
+        filters: false
+        filter_groups: false
+      display_description: ''
+      display_extenders: {  }
+      allow:
+        items_per_page: false
+    cache_metadata:
+      max-age: -1
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url
+        - url.query_args
+        - 'user.node_grants:view'
+      tags:
+        - 'config:field.storage.node.field_branch'
+        - 'config:search_api.index.content_events'
+        - 'search_api_list:content_events'

web/modules/custom/dpl_search/dpl_search.module

@@ -8,6 +8,7 @@
 use Drupal\Core\Url;
 use Drupal\dpl_react_apps\Controller\DplReactAppsController;
 use Drupal\dpl_search\DplSearchSettings;
+use Drupal\taxonomy\TermInterface;
 use Drupal\views\ViewExecutable;
 use Drupal\views\Views;
 
@@ -73,6 +74,10 @@ function dpl_search_preprocess_views_view(array &$variables): void {
     return;
   }
 
+  if ($view->current_display !== 'page') {
+    return;
+  }
+
   // Hiding the exposed search filter, as we display it in the header.
   unset($variables['exposed']);
 
@@ -137,6 +142,73 @@ function dpl_search_preprocess_page(array &$variables): void {
   ];
 }
 
+/**
+ * Implements theme_preprocess_taxonomy_term().
+ *
+ * Show a view of tagged content on terms of certain vocabularies.
+ * The view is identical to the editorial view on /search/web, but with
+ * contextual filters applied.
+ */
+function dpl_search_preprocess_taxonomy_term(array &$variables): void {
+  $view_mode = $variables['view_mode'] ?? NULL;
+
+  // If we're not on the full display, we don't want to load the search view.
+  if ($view_mode !== 'full') {
+    return;
+  }
+
+  $term = $variables['term'] ?? NULL;
+  $bundle = $term?->bundle();
+
+  // The vocabularies we allow as contextual filters in the embedded view.
+  // ! IMPORTANT ! - The order in this array matters, as views does not allow
+  // for named contextual filters - it MUST match the order that is set in
+  // the Views UI.
+  $allowed_contextual_vocabularies = [
+    'categories',
+    'tags',
+  ];
+
+  if (!($term instanceof TermInterface) ||
+      !in_array($bundle, $allowed_contextual_vocabularies)) {
+    return;
+  }
+
+  $contextual_filters = [];
+
+  // Looping through the allowed vocabularies, and setting the current
+  // term as a contextual filter, if the term is in that vocabulary.
+  foreach ($allowed_contextual_vocabularies as $vocabulary) {
+    if ($vocabulary === $bundle) {
+      $contextual_filters[] = $term->id();
+    }
+    else {
+      $contextual_filters[] = 'all';
+    }
+  }
+
+  $view = Views::getView(DplSearchSettings::EDITORIAL_VIEW_ID);
+
+  if (!($view instanceof ViewExecutable)) {
+    return;
+  }
+
+  $view->setDisplay('term_page');
+  $view->setArguments($contextual_filters);
+  $view->execute();
+  $view->setTitle(t(
+    'Showing web results related to "@term" (@total_results)',
+    ['@term' => $term->label(), '@total_results' => $view->total_rows],
+    ['context' => 'dpl_search']
+  ));
+
+  // We only want the view to show up - not the title, which cannot be removed
+  // through the Drupal admin UI.
+  unset($variables['content']);
+
+  $variables['content']['view'] = $view->buildRenderable('term_page');
+}
+
 /**
  * Implements hook_theme().
  */