Issue #2754977 by dmsmidt, marcvangend, mohit_aghera, Getekid, tim.plunkett,...

Issue #2754977 by dmsmidt, marcvangend, mohit_aghera, Getekid, tim.plunkett, ndf: Enhance formErrorHandler to include children errors on RenderElements

core/lib/Drupal/Core/Form/FormErrorHandler.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\Core\Form;
 
+use Drupal\Component\Utility\NestedArray;
 use Drupal\Core\Render\Element;
 
 /**
@@ -43,21 +44,115 @@ protected function displayErrorMessages(array $form, FormStateInterface $form_st
   }
 
   /**
-   * Stores the errors of each element directly on the element.
+   * Stores errors and a list of child element errors directly on each element.
    *
-   * We must provide a way for non-form functions to check the errors for a
-   * specific element. The most common usage of this is a #pre_render callback.
+   * Grouping elements like containers, details, fieldgroups and fieldsets may
+   * need error info from their child elements to be able to accessibly show
+   * form error messages to a user. For example, a details element should be
+   * opened when child elements have errors.
    *
-   * @param array $elements
-   *   An associative array containing the structure of a form element.
+   * Grouping example:
+   * Assume you have a 'street' element somewhere in a form, which is displayed
+   * in a details element 'address'. It might be:
+   * @code
+   * $form['street'] = [
+   *   '#type' => 'textfield',
+   *   '#title' => $this->t('Street'),
+   *   '#group' => 'address',
+   *   '#required' => TRUE,
+   * ];
+   * $form['address'] = [
+   *   '#type' => 'details',
+   *   '#title' => $this->t('Address'),
+   * ];
+   * @endcode
+   *
+   * When submitting an empty street field, the generated error is available to
+   * the different render elements like so:
+   * @code
+   * // The street textfield element.
+   * $element = [
+   *   '#errors' => {Drupal\Core\StringTranslation\TranslatableMarkup},
+   *   '#children_errors' => [],
+   * ];
+   * // The address detail element.
+   * $element = [
+   *   '#errors' => null,
+   *   '#children_errors' => [
+   *      'street' => {Drupal\Core\StringTranslation\TranslatableMarkup}
+   *   ],
+   * ];
+   * @endcode
+   *
+   * The list of child element errors of an element is an associative array. A
+   * child element error is keyed with the #array_parents value of the
+   * respective element. The key is formed by imploding this value with '][' as
+   * glue. For example, a value ['contact_info', 'name'] becomes
+   * 'contact_info][name'.
+   *
+   * @param array $form
+   *   An associative array containing a reference to the complete structure of
+   *   the form.
    * @param \Drupal\Core\Form\FormStateInterface $form_state
    *   The current state of the form.
+   * @param array $elements
+   *   An associative array containing the part of the form structure that will
+   *   be processed while traversing up the tree. For recursion only; leave
+   *   empty when calling this method.
    */
-  protected function setElementErrorsFromFormState(array &$elements, FormStateInterface &$form_state) {
-    // Recurse through all children.
+  protected function setElementErrorsFromFormState(array &$form, FormStateInterface $form_state, array &$elements = []) {
+    // At the start of traversing up the form tree set the to be processed
+    // elements to the complete form structure by reference so that we can
+    // modify the original form. When processing grouped elements a reference to
+    // the complete form is needed.
+    if (empty($elements)) {
+      $elements = &$form;
+    }
+
+    // Recurse through all element children.
     foreach (Element::children($elements) as $key) {
-      if (isset($elements[$key]) && $elements[$key]) {
-        $this->setElementErrorsFromFormState($elements[$key], $form_state);
+      if (!empty($elements[$key])) {
+        // Get the child by reference so that we can update the original form.
+        $child = &$elements[$key];
+
+        // Call self to traverse up the form tree. The current element's child
+        // contains the next elements to be processed.
+        $this->setElementErrorsFromFormState($form, $form_state, $child);
+
+        $children_errors = [];
+
+        // Inherit all recorded "children errors" of the direct child.
+        if (!empty($child['#children_errors'])) {
+          $children_errors = $child['#children_errors'];
+        }
+
+        // Additionally store the errors of the direct child itself, keyed by
+        // it's parent elements structure.
+        if (!empty($child['#errors'])) {
+          $child_parents = implode('][', $child['#array_parents']);
+          $children_errors[$child_parents] = $child['#errors'];
+        }
+
+        if (!empty($elements['#children_errors'])) {
+          $elements['#children_errors'] += $children_errors;
+        }
+        else {
+          $elements['#children_errors'] = $children_errors;
+        }
+
+        // If this direct child belongs to a group populate the grouping element
+        // with the children errors.
+        if (!empty($child['#group'])) {
+          $parents = explode('][', $child['#group']);
+          $group_element = NestedArray::getValue($form, $parents);
+          if (isset($group_element['#children_errors'])) {
+            $group_element['#children_errors'] = $group_element['#children_errors'] + $children_errors;
+          }
+          else {
+            $group_element['#children_errors'] = $children_errors;
+          }
+          NestedArray::setValue($form, $parents, $group_element);
+        }
       }
     }
 

core/modules/inline_form_errors/tests/src/Unit/FormErrorHandlerTest.php

@@ -50,25 +50,30 @@ public function testDisplayErrorMessagesInline() {
 
     $form = [
       '#parents' => [],
+      '#array_parents' => [],
     ];
     $form['test1'] = [
       '#type' => 'textfield',
       '#title' => 'Test 1',
       '#parents' => ['test1'],
+      '#array_parents' => ['test1'],
       '#id' => 'edit-test1',
     ];
     $form['test2'] = [
       '#type' => 'textfield',
       '#title' => 'Test 2 & a half',
       '#parents' => ['test2'],
+      '#array_parents' => ['test2'],
       '#id' => 'edit-test2',
     ];
     $form['fieldset'] = [
       '#parents' => ['fieldset'],
+      '#array_parents' => ['fieldset'],
       'test3' => [
         '#type' => 'textfield',
         '#title' => 'Test 3',
         '#parents' => ['fieldset', 'test3'],
+        '#array_parents' => ['fieldset', 'test3'],
         '#id' => 'edit-test3',
       ],
     ];
@@ -76,18 +81,21 @@ public function testDisplayErrorMessagesInline() {
       '#type' => 'textfield',
       '#title' => 'Test 4',
       '#parents' => ['test4'],
+      '#array_parents' => ['test4'],
       '#id' => 'edit-test4',
       '#error_no_message' => TRUE,
     ];
     $form['test5'] = [
       '#type' => 'textfield',
       '#parents' => ['test5'],
+      '#array_parents' => ['test5'],
       '#id' => 'edit-test5',
     ];
     $form['test6'] = [
       '#type' => 'value',
       '#title' => 'Test 6',
       '#parents' => ['test6'],
+      '#array_parents' => ['test6'],
       '#id' => 'edit-test6',
     ];
     $form_state = new FormState();
@@ -114,11 +122,13 @@ public function testSetElementErrorsFromFormState() {
 
     $form = [
       '#parents' => [],
+      '#array_parents' => [],
     ];
     $form['test'] = [
       '#type' => 'textfield',
       '#title' => 'Test',
       '#parents' => ['test'],
+      '#array_parents' => ['test'],
       '#id' => 'edit-test',
     ];
     $form_state = new FormState();

core/tests/Drupal/Tests/Core/Form/FormErrorHandlerTest.php

@@ -41,37 +41,44 @@ public function testDisplayErrorMessages() {
 
     $form = [
       '#parents' => [],
+      '#array_parents' => [],
     ];
     $form['test1'] = [
       '#type' => 'textfield',
       '#title' => 'Test 1',
       '#parents' => ['test1'],
+      '#array_parents' => ['test1'],
       '#id' => 'edit-test1',
     ];
     $form['test2'] = [
       '#type' => 'textfield',
       '#title' => 'Test 2 & a half',
       '#parents' => ['test2'],
+      '#array_parents' => ['test2'],
       '#id' => 'edit-test2',
     ];
     $form['fieldset'] = [
       '#parents' => ['fieldset'],
+      '#array_parents' => ['fieldset'],
       'test3' => [
         '#type' => 'textfield',
         '#title' => 'Test 3',
         '#parents' => ['fieldset', 'test3'],
+        '#array_parents' => ['fieldset', 'test3'],
         '#id' => 'edit-test3',
       ],
     ];
     $form['test5'] = [
       '#type' => 'textfield',
       '#parents' => ['test5'],
+      '#array_parents' => ['test5'],
       '#id' => 'edit-test5',
     ];
     $form['test6'] = [
       '#type' => 'value',
       '#title' => 'Test 6',
       '#parents' => ['test6'],
+      '#array_parents' => ['test6'],
       '#id' => 'edit-test6',
     ];
     $form_state = new FormState();
@@ -96,17 +103,91 @@ public function testSetElementErrorsFromFormState() {
 
     $form = [
       '#parents' => [],
+      '#array_parents' => [],
     ];
     $form['test'] = [
       '#type' => 'textfield',
       '#title' => 'Test',
       '#parents' => ['test'],
+      '#array_parents' => ['test'],
       '#id' => 'edit-test',
     ];
+    $form['details'] = [
+      '#type' => 'details',
+      '#title' => 'Details grouping test',
+      '#parents' => ['details'],
+      '#array_parents' => ['details'],
+      '#id' => 'edit-details',
+    ];
+    $form['grouping_test'] = [
+      '#type' => 'textfield',
+      '#title' => 'Grouping test',
+      '#parents' => ['grouping_test'],
+      '#array_parents' => ['grouping_test'],
+      '#id' => 'edit-grouping-test',
+      '#group' => 'details',
+    ];
+    $form['grouping_test2'] = [
+      '#type' => 'textfield',
+      '#title' => 'Grouping test 2',
+      '#parents' => ['grouping_test2'],
+      '#array_parents' => ['grouping_test2'],
+      '#id' => 'edit-grouping-test2',
+      '#group' => 'details',
+    ];
+    $form['details2'] = [
+      '#type' => 'details',
+      '#title' => 'Details grouping test 2',
+      '#parents' => ['details2'],
+      '#array_parents' => ['details2'],
+      '#id' => 'edit-details2',
+    ];
+    $form['grouping_test3'] = [
+      '#type' => 'textfield',
+      '#title' => 'Grouping test 3',
+      '#parents' => ['grouping_test3'],
+      '#array_parents' => ['grouping_test3'],
+      '#id' => 'edit-grouping-test3',
+      '#group' => 'details2',
+    ];
+    $form['fieldset'] = [
+      '#type' => 'fieldset',
+      '#parents' => ['fieldset'],
+      '#array_parents' => ['fieldset'],
+      '#id' => 'edit-fieldset',
+      'nested_test' => [
+        '#type' => 'textfield',
+        '#title' => 'Nested test',
+        '#parents' => ['fieldset', 'nested_test'],
+        '#array_parents' => ['fieldset', 'nested_test'],
+        '#id' => 'edit-nested_test',
+      ],
+      'nested_test2' => [
+        '#type' => 'textfield',
+        '#title' => 'Nested test2',
+        '#parents' => ['fieldset', 'nested_test2'],
+        '#array_parents' => ['fieldset', 'nested_test2'],
+        '#id' => 'edit-nested_test2',
+      ],
+    ];
     $form_state = new FormState();
     $form_state->setErrorByName('test', 'invalid');
+    $form_state->setErrorByName('grouping_test', 'invalid');
+    $form_state->setErrorByName('grouping_test2', 'invalid');
+    $form_state->setErrorByName('fieldset][nested_test', 'invalid');
+    $form_state->setErrorByName('fieldset][nested_test2', 'invalid2');
     $form_error_handler->handleFormErrors($form, $form_state);
     $this->assertSame('invalid', $form['test']['#errors']);
+    $this->assertSame([
+      'grouping_test' => 'invalid',
+      'grouping_test2' => 'invalid',
+    ], $form['details']['#children_errors']);
+    $this->assertSame([
+      'fieldset][nested_test' => 'invalid',
+      'fieldset][nested_test2' => 'invalid2',
+    ], $form['fieldset']['#children_errors']);
+    $this->assertEmpty($form['details2']['#children_errors'], 'Children errors are empty for grouping element.');
+    $this->assertCount(5, $form['#children_errors']);
   }
 
 }