Issue #2183565 by DuaelFr, melvinlouwerse, grndlvl, cesarmiquel, Sweetchuck,...

Issue #2183565 by DuaelFr, melvinlouwerse, grndlvl, cesarmiquel, Sweetchuck, yogeshmpawar, marvil07, BetoAveiga: Avoid loading all terms on the taxonomy overview form

Closes #2183565

core/modules/taxonomy/src/Form/OverviewTerms.php

@@ -158,7 +158,9 @@ public function buildForm(array $form, FormStateInterface $form_state, Vocabular
 
     $delta = 0;
     $term_deltas = [];
-    $tree = $this->storageController->loadTree($taxonomy_vocabulary->id(), 0, NULL, TRUE);
+    // Terms are not loaded to avoid excessive memory consumption for large
+    // vocabularies. Needed terms are loaded explicitly afterward.
+    $tree = $this->storageController->loadTree($taxonomy_vocabulary->id(), 0, NULL, FALSE);
     $tree_index = 0;
     $complete_tree = NULL;
     do {
@@ -179,8 +181,8 @@ public function buildForm(array $form, FormStateInterface $form_state, Vocabular
       }
 
       // Do not let a term start the page that is not at the root.
-      $term = $tree[$tree_index];
-      if (isset($term->depth) && ($term->depth > 0) && !isset($back_step)) {
+      $raw_term = $tree[$tree_index];
+      if (isset($raw_term->depth) && ($raw_term->depth > 0) && !isset($back_step)) {
         $back_step = 0;
         while ($parent_term = $tree[--$tree_index]) {
           $before_entries--;
@@ -195,7 +197,7 @@ public function buildForm(array $form, FormStateInterface $form_state, Vocabular
       $back_step = $back_step ?? 0;
 
       // Continue rendering the tree until we reach the a new root item.
-      if ($page_entries >= $page_increment + $back_step + 1 && $term->depth == 0 && $root_entries > 1) {
+      if ($page_entries >= $page_increment + $back_step + 1 && $raw_term->depth == 0 && $root_entries > 1) {
         $complete_tree = TRUE;
         // This new item at the root level is the first item on the next page.
         $after_entries++;
@@ -208,20 +210,30 @@ public function buildForm(array $form, FormStateInterface $form_state, Vocabular
       // Finally, if we've gotten down this far, we're rendering a term on this
       // page.
       $page_entries++;
-      $term_deltas[$term->id()] = isset($term_deltas[$term->id()]) ? $term_deltas[$term->id()] + 1 : 0;
-      $key = 'tid:' . $term->id() . ':' . $term_deltas[$term->id()];
+      $term_deltas[$raw_term->tid] = isset($term_deltas[$raw_term->tid]) ? $term_deltas[$raw_term->tid] + 1 : 0;
+      $key = 'tid:' . $raw_term->tid . ':' . $term_deltas[$raw_term->tid];
 
       // Keep track of the first term displayed on this page.
       if ($page_entries == 1) {
-        $form['#first_tid'] = $term->id();
+        $form['#first_tid'] = $raw_term->tid;
       }
       // Keep a variable to make sure at least 2 root elements are displayed.
-      if ($term->parents[0] == 0) {
+      if ($raw_term->parents[0] == 0) {
         $root_entries++;
       }
-      $current_page[$key] = $term;
+      $current_page[$key] = $raw_term;
     } while (isset($tree[++$tree_index]));
 
+    // Load all the terms we're going to display and set the weight and parents
+    // from the tree.
+    $terms = $this->storageController->loadMultiple(array_keys($term_deltas));
+    $current_page = array_map(function ($raw_term) use ($terms) {
+      $term = $terms[$raw_term->tid];
+      $term->depth = $raw_term->depth;
+      $term->parents = $raw_term->parents;
+      return $term;
+    }, $current_page);
+
     // Because we didn't use a pager query, set the necessary pager variables.
     $total_entries = $before_entries + $page_entries + $after_entries;
     $this->pagerManager->createPager($total_entries, $page_increment);
@@ -518,7 +530,9 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
 
     $vocabulary = $form_state->get(['taxonomy', 'vocabulary']);
     $changed_terms = [];
-    $tree = $this->storageController->loadTree($vocabulary->id(), 0, NULL, TRUE);
+    // Terms are not loaded to avoid excessive memory consumption for large
+    // vocabularies. Needed terms are loaded explicitly afterward.
+    $tree = $this->storageController->loadTree($vocabulary->id(), 0, NULL, FALSE);
 
     if (empty($tree)) {
       return;
@@ -526,14 +540,14 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
 
     // Build a list of all terms that need to be updated on previous pages.
     $weight = 0;
-    $term = $tree[0];
-    while ($term->id() != $form['#first_tid']) {
-      if ($term->parents[0] == 0 && $term->getWeight() != $weight) {
-        $term->setWeight($weight);
-        $changed_terms[$term->id()] = $term;
+    $raw_term = $tree[0];
+    $term_weights = [];
+    while ($raw_term->tid != $form['#first_tid']) {
+      if ($raw_term->parents[0] == 0 && $raw_term->weight != $weight) {
+        $term_weights[$raw_term->tid] = $weight;
       }
       $weight++;
-      $term = $tree[$weight];
+      $raw_term = $tree[$weight];
     }
 
     // Renumber the current page weights and assign any new parents.
@@ -565,14 +579,19 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
 
     // Build a list of all terms that need to be updated on following pages.
     for ($weight; $weight < count($tree); $weight++) {
-      $term = $tree[$weight];
-      if ($term->parents[0] == 0 && $term->getWeight() != $weight) {
-        $term->parent->target_id = $term->parents[0];
-        $term->setWeight($weight);
-        $changed_terms[$term->id()] = $term;
+      $raw_term = $tree[$weight];
+      if ($raw_term->parents[0] == 0 && $raw_term->weight != $weight) {
+        $term_weights[$raw_term->tid] = $weight;
       }
     }
 
+    // Load all the items that need to be updated at once.
+    $terms = $this->storageController->loadMultiple(array_keys($term_weights));
+    foreach ($terms as $term) {
+      $term->setWeight($term_weights[$term->id()]);
+      $changed_terms[$term->id()] = $term;
+    }
+
     if (!empty($changed_terms)) {
       $pending_term_ids = $this->storageController->getTermIdsWithPendingRevisions();