Issue #3039982 - Add common parent

hierarchical_term_formatter.theme.inc

@@ -7,6 +7,7 @@
 
 use Drupal\Component\Utility\Html;
 use Drupal\Core\Link;
+use Drupal\Core\Render\Markup;
 
 /**
  * Prepares term objects for Twig template.
@@ -19,15 +20,30 @@ function template_preprocess_hierarchical_term_formatter(array &$variables) {
   $terms = [];
   $variables['terms_objects'] = $variables['terms'];
 
-  /** @var \Drupal\taxonomy\TermInterface $term */
-  foreach ($variables['terms'] as $term) {
-    if ($variables['link']) {
-      $url = $term->toUrl();
-      $link = Link::fromTextAndUrl($term->label(), $url)->toRenderable();
-      $terms[] = \Drupal::service('renderer')->render($link);
+  /** @var \Drupal\taxonomy\TermInterface|[] $item */
+  foreach ($variables['terms'] as $item) {
+    if (is_array($item)) {
+      $group = [];
+      foreach ($item as $value) {
+        if ($variables['link']) {
+          $link = Link::fromTextAndUrl($value->label(), $value->toUrl())->toRenderable();
+          $group[] = \Drupal::service('renderer')->render($link);
+        }
+        else {
+          $group[] = $value->label();
+        }
+      }
+
+      $terms[] = Markup::create(implode('<span class="child-separator">, </span>', $group));
     }
     else {
-      $terms[] = $term->label();
+      if ($variables['link']) {
+        $link = Link::fromTextAndUrl($item->label(), $item->toUrl())->toRenderable();
+        $terms[] = \Drupal::service('renderer')->render($link);
+      }
+      else {
+        $terms[] = $item->label();
+      }
     }
   }
 

src/Plugin/Field/FieldFormatter/HierarchicalFormatter.php

@@ -81,6 +81,7 @@ class HierarchicalFormatter extends EntityReferenceFormatterBase {
   private function displayOptions() {
     return [
       'all' => $this->t('The selected term and all of its parents'),
+      'grouping' => $this->t('Grouping terms with the same parent together'),
       'parents' => $this->t('Just the parent terms'),
       'root' => $this->t('Just the topmost/root term'),
       'nonroot' => $this->t('Any non-topmost/root terms'),
@@ -243,6 +244,39 @@ class HierarchicalFormatter extends EntityReferenceFormatterBase {
           }
           break;
 
+        case 'grouping':
+          $term_tree = array_reverse($this->taxonomyTermStorage->loadAllParents($tid));
+
+          $group = FALSE;
+          if (!empty($elements)) {
+            foreach ($elements as $key => $terms) {
+              // Add child to the common parent.
+              if ($term_tree[0]->id() == $terms['#terms'][0]->id()) {
+                if (isset($term_tree[1])) {
+                  if (isset($elements[$key]['#terms'][1])) {
+                    // Check if we already add a child.
+                    if (is_array($elements[$key]['#terms'][1])) {
+                      $elements[$key]['#terms'][1] = array_merge($elements[$key]['#terms'][1], [$term_tree[1]]);
+                    }
+                    else {
+                      $elements[$key]['#terms'][1] = array_merge([$elements[$key]['#terms'][1]], [$term_tree[1]]);
+                    }
+                  }
+                  else {
+                    $elements[$key]['#terms'][1] = $term_tree[1];
+                  }
+                }
+                $group = TRUE;
+              }
+            }
+          }
+
+          // Skip adding new element.
+          if ($group) {
+            continue 2;
+          }
+          break;
+
         default:
           $term_tree = array_reverse($this->taxonomyTermStorage->loadAllParents($tid));
           break;