Issue #3198500: Allow fallback on lower priority breadcrumb builders

src/BreadcrumbBuilder.php

@@ -156,6 +156,10 @@ class BreadcrumbBuilder implements BreadcrumbBuilderInterface {
       return FALSE;
     }
 
+    if (!$this->matchPaths($route_match) && !$this->matchEntity($route_match)) {
+      return FALSE;
+    }
+
     return TRUE;
   }
 
@@ -454,6 +458,37 @@ class BreadcrumbBuilder implements BreadcrumbBuilderInterface {
     return FALSE;
   }
 
+  /**
+   * Check breadcrumbs by entity.
+   *
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   Route match.
+   *
+   * @return bool
+   *   True if a match was found, false otherwise.
+   *
+   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
+   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
+   */
+  protected function matchEntity(RouteMatchInterface $route_match) {
+    $params = $route_match->getParameters()->all();
+
+    $entityTypeIds = array_keys($params);
+    $entityTypeId = reset($entityTypeIds);
+
+    $breadcrumbSettings = $this->entityTypeManager->getStorage('custom_breadcrumbs')
+      ->loadByProperties([
+        'entityType' => $entityTypeId,
+        'status' => TRUE,
+        'type' => 1,
+      ]);
+
+    $this->filterPerBundle($breadcrumbSettings, $route_match);
+    $this->filterPerLanguage($breadcrumbSettings);
+
+    return !empty($breadcrumbSettings);
+  }
+
   /**
    * Helper method to trim title.
    *