Cache the trees structures for treeViews used in the sidebar.

src/Repository/StructuralDBElementRepository.php

@@ -22,9 +22,12 @@
 namespace App\Repository;
 
 use App\Entity\Base\StructuralDBElement;
+use App\Helpers\Trees\StructuralDBElementIterator;
+use App\Helpers\TreeViewNode;
 use Doctrine\ORM\EntityRepository;
+use Symfony\Component\Stopwatch\Stopwatch;
 
-class StructuralDBElementRepository extends EntityRepository
+class StructuralDBElementRepository extends NamedDBElementRepository
 {
     /**
      * Finds all nodes without a parent node. They are our root nodes.
@@ -36,6 +39,31 @@ class StructuralDBElementRepository extends EntityRepository
         return $this->findBy(['parent' => null], ['name' => 'ASC']);
     }
 
+
+    /**
+     * Gets a tree of TreeViewNode elements. The root elements has $parent as parent.
+     * The treeview is generic, that means the href are null and ID values are set.
+     * @param  StructuralDBElement|null  $parent The parent the root elements should have.
+     * @return TreeViewNode[]
+     */
+    public function getGenericNodeTree(?StructuralDBElement $parent = null) : array
+    {
+        $result = [];
+
+        $entities = $this->findBy(['parent' => $parent], ['name' => 'ASC']);
+        foreach ($entities as $entity) {
+            /** @var StructuralDBElement $entity */
+            //Make a recursive call to find all children nodes
+            $children = $this->getGenericNodeTree($entity);
+            $node = new TreeViewNode($entity->getName(), null, $children);
+            //Set the ID of this entity to later be able to reconstruct the URL
+            $node->setId($entity->getID());
+            $result[] = $node;
+        }
+
+        return $result;
+    }
+
     /**
      * Gets a flattened hierarchical tree. Useful for generating option lists.
      *
@@ -49,16 +77,13 @@ class StructuralDBElementRepository extends EntityRepository
 
         $entities = $this->findBy(['parent' => $parent], ['name' => 'ASC']);
 
-        /*
-         * I think it is very difficult to replace this recursive array_merge,
-         * so if you want to change it you should have a better idea than adding each list to $result array
-         * and do an array_merge(...$result) at the end.
-         */
+        $elementIterator = new StructuralDBElementIterator($entities);
+        $recursiveIterator = new \RecursiveIteratorIterator($elementIterator, \RecursiveIteratorIterator::SELF_FIRST);
+        //$result = iterator_to_array($recursiveIterator);
 
-        foreach ($entities as $entity) {
-            /* @var StructuralDBElement $entity */
-            $result[] = $entity;
-            $result = array_merge($result, $this->toNodesList($entity));
+        //We can not use iterator_to_array here or we get only the parent elements
+        foreach($recursiveIterator as $item) {
+            $result[] = $item;
         }
 
         return $result;