Issue #2591515 by joelpittet, Cottser, lauriii, NickWilde, kostyashupenko, alexpott, xjm: Move twig_without() to the TwigExtension where all the other filters are and deprecate

core/lib/Drupal/Core/Template/TwigEnvironment.php

@@ -60,6 +60,7 @@ class TwigEnvironment extends \Twig_Environment {
 
     // Ensure that twig.engine is loaded, given that it is needed to render a
     // template because functions like TwigExtension::escapeFilter() are called.
+    // @todo remove in Drupal 9.0.0 https://www.drupal.org/node/3011393.
     require_once $root . '/core/themes/engines/twig/twig.engine';
 
     $this->templateClasses = [];

core/lib/Drupal/Core/Template/TwigExtension.php

@@ -177,7 +177,7 @@ class TwigExtension extends \Twig_Extension {
       new \Twig_SimpleFilter('safe_join', [$this, 'safeJoin'], ['needs_environment' => TRUE, 'is_safe' => ['html']]),
 
       // Array filters.
-      new \Twig_SimpleFilter('without', 'twig_without'),
+      new \Twig_SimpleFilter('without', [$this, 'withoutFilter']),
 
       // CSS class and ID filters.
       new \Twig_SimpleFilter('clean_class', '\Drupal\Component\Utility\Html::getClass'),
@@ -641,4 +641,37 @@ class TwigExtension extends \Twig_Extension {
     return new Attribute($attributes);
   }
 
+  /**
+   * Removes child elements from a copy of the original array.
+   *
+   * Creates a copy of the renderable array and removes child elements by key
+   * specified through filter's arguments. The copy can be printed without these
+   * elements. The original renderable array is still available and can be used
+   * to print child elements in their entirety in the twig template.
+   *
+   * @param array|object $element
+   *   The parent renderable array to exclude the child items.
+   * @param string[] ...
+   *   The string keys of $element to prevent printing.
+   *
+   * @return array
+   *   The filtered renderable array.
+   */
+  public function withoutFilter($element) {
+    if ($element instanceof \ArrayAccess) {
+      $filtered_element = clone $element;
+    }
+    else {
+      $filtered_element = $element;
+    }
+    $args = func_get_args();
+    unset($args[0]);
+    foreach ($args as $arg) {
+      if (isset($filtered_element[$arg])) {
+        unset($filtered_element[$arg]);
+      }
+    }
+    return $filtered_element;
+  }
+
 }

core/modules/system/tests/src/Kernel/Theme/TwigFilterTest.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\system\Kernel\Theme;
 
+use Drupal\Core\Extension\Extension;
 use Drupal\KernelTests\KernelTestBase;
 
 /**
@@ -120,4 +121,39 @@ class TwigFilterTest extends KernelTestBase {
     }
   }
 
+  /**
+   * Test "twig_without" filter function.
+   *
+   * @expectedDeprecation twig_without() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Use \Drupal\Core\Template\TwigExtension::withoutFilter(). See https://www.drupal.org/node/3011154.
+   * @group legacy
+   */
+  public function testLegacyTwigWithoutFunction() {
+    // Load the twig engine to ensure twig_without() exists.
+    $twig_engine = new Extension($this->root, 'theme_engine', 'core/themes/engines/twig/twig.info.yml', 'twig.engine');
+    $twig_engine->load();
+
+    $filter_test = [
+      'red' => '#F00',
+      'green' => '#0F0',
+      'blue' => '#00F',
+    ];
+
+    // Filter out red key.
+    $result_without_red = twig_without($filter_test, 'red');
+    $expected_without_red = $filter_test;
+    unset($expected_without_red['red']);
+    $this->assertSame($expected_without_red, $result_without_red);
+
+    // Filter nothing and check the array is unaltered.
+    $result_unaltered = twig_without($filter_test);
+    $this->assertSame($filter_test, $result_unaltered);
+
+    // Filter out blue and green.
+    $result_without_blue_green = twig_without($filter_test, 'blue', 'green');
+    $expected_without_blue_green = $filter_test;
+    unset($expected_without_blue_green['blue']);
+    unset($expected_without_blue_green['green']);
+    $this->assertSame($expected_without_blue_green, $result_without_blue_green);
+  }
+
 }

core/themes/engines/twig/twig.engine

@@ -133,20 +133,14 @@ function twig_render_template($template_file, array $variables) {
  *
  * @return array
  *   The filtered renderable array.
+ *
+ * @deprecated in Drupal 8.7.x and will be removed before 9.0.0. Use
+ *   \Drupal\Core\Template\TwigExtension::withoutFilter() instead.
  */
 function twig_without($element) {
-  if ($element instanceof ArrayAccess) {
-    $filtered_element = clone $element;
-  }
-  else {
-    $filtered_element = $element;
-  }
-  $args = func_get_args();
-  unset($args[0]);
-  foreach ($args as $arg) {
-    if (isset($filtered_element[$arg])) {
-      unset($filtered_element[$arg]);
-    }
-  }
-  return $filtered_element;
+  @trigger_error('twig_without() is deprecated in Drupal 8.7.x and will be removed before Drupal 9.0.0. Use \Drupal\Core\Template\TwigExtension::withoutFilter(). See https://www.drupal.org/node/3011154.', E_USER_DEPRECATED);
+  /** @var \Drupal\Core\Template\TwigExtension $extension */
+  $extension = \Drupal::service('twig.extension');
+
+  return call_user_func_array([$extension, 'withoutFilter'], func_get_args());
 }