Use a "text_format" element when a string of type "text/html" is requested

Author: Dominic Tubach

src/Form/AbstractJsonFormsForm.php

@@ -25,6 +25,7 @@
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\json_forms\Form\Util\FieldNameUtil;
 use Drupal\json_forms\Form\Util\FormCallbackExecutor;
+use Drupal\json_forms\Form\Util\FormValidationUtil;
 use Drupal\json_forms\Form\Validation\FormValidationMapperInterface;
 use Drupal\json_forms\Form\Validation\FormValidatorInterface;
 use Drupal\json_forms\JsonForms\Definition\DefinitionFactory;
@@ -137,16 +138,28 @@ protected function buildJsonFormsForm(
    * @param \Drupal\Core\Form\FormStateInterface $formState
    */
   public function validateForm(array &$form, FormStateInterface $formState): void {
+    parent::validateForm($form, $formState);
+    FormCallbackExecutor::executePreSchemaValidationCallbacks($formState);
+
     if ($formState->isSubmitted() || $formState->isValidationEnforced()) {
       if (TRUE === $formState->get('$limitValidationUsed')) {
         // We cannot use Drupal validation errors if the form uses limited
         // validation. They might contain errors that with the submitted data
         // would be ignored. (Avoiding Drupal validation is not possible on form
         // submit.)
+        $keepFormErrorElementKeys = FormValidationUtil::getKeepFormErrorElementKeys($formState);
+        $keepFormErrors = array_map(
+          fn (array $elementKey) => $formState->getError(['#parents' => $elementKey]),
+          $keepFormErrorElementKeys
+        );
         $formState->clearErrors();
+        foreach ($keepFormErrorElementKeys as $index => $elementKey) {
+          if (NULL !== $keepFormErrors[$index]) {
+            $element = ['#parents' => $elementKey];
+            $formState->setError($element, $keepFormErrors[$index]);
+          }
+        }
       }
-      parent::validateForm($form, $formState);
-      FormCallbackExecutor::executePreSchemaValidationCallbacks($formState);
       $validationResult = $this->formValidator->validate(
         // @phpstan-ignore-next-line
         $formState->get('jsonSchema'),

src/Form/Control/Callbacks/HtmlCallbacks.php

@@ -0,0 +1,40 @@
+<?php
+
+/*
+ * Copyright (C) 2022 SYSTOPIA GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace Drupal\json_forms\Form\Control\Callbacks;
+
+use Drupal\Core\Form\FormStateInterface;
+
+final class HtmlCallbacks {
+
+  /**
+   * Converts the value set by the "text_format" form element at the given key.
+   * This method is called after Drupal validation.
+   *
+   * @phpstan-param array<int|string> $elementKey
+   */
+  public static function convertValue(FormStateInterface $formState, string $callbackKey, array $elementKey): void {
+    /** @var array{value: string, format: string} $value */
+    $value = $formState->getValue($elementKey);
+    $formState->setValue($elementKey, $value['value'] ?? NULL);
+  }
+
+}

src/Form/Control/HtmlArrayFactory.php

@@ -0,0 +1,89 @@
+<?php
+
+/*
+ * Copyright (C) 2025 SYSTOPIA GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace Drupal\json_forms\Form\Control;
+
+use Assert\Assertion;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\json_forms\Form\AbstractConcreteFormArrayFactory;
+use Drupal\json_forms\Form\Control\Callbacks\HtmlCallbacks;
+use Drupal\json_forms\Form\Control\Callbacks\StringValueCallback;
+use Drupal\json_forms\Form\Control\Util\BasicFormPropertiesFactory;
+use Drupal\json_forms\Form\FormArrayFactoryInterface;
+use Drupal\json_forms\Form\Util\FormCallbackRegistrator;
+use Drupal\json_forms\Form\Util\FormValidationUtil;
+use Drupal\json_forms\JsonForms\Definition\Control\ControlDefinition;
+use Drupal\json_forms\JsonForms\Definition\Control\StringControlDefinition;
+use Drupal\json_forms\JsonForms\Definition\DefinitionInterface;
+
+class HtmlArrayFactory extends AbstractConcreteFormArrayFactory {
+
+  public static function getPriority(): int {
+    return StringArrayFactory::getPriority() + 1;
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  public function createFormArray(
+    DefinitionInterface $definition,
+    FormStateInterface $formState,
+    FormArrayFactoryInterface $formArrayFactory
+  ): array {
+    Assertion::isInstanceOf($definition, ControlDefinition::class);
+    /** @var \Drupal\json_forms\JsonForms\Definition\Control\ControlDefinition $definition */
+    $definition = StringControlDefinition::fromDefinition($definition);
+    /** @var \Drupal\json_forms\JsonForms\Definition\Control\StringControlDefinition $definition */
+
+    $form = [
+      '#type' => 'text_format',
+      '#value_callback' => StringValueCallback::class . '::convert',
+    ] + BasicFormPropertiesFactory::createFieldProperties($definition, $formState);
+
+    if (NULL !== $definition->getMaxLength()) {
+      $form['#maxlength'] = $definition->getMaxLength();
+    }
+
+    if (NULL !== $definition->getPattern()) {
+      $form['#pattern'] = $definition->getPattern();
+    }
+
+    /** @var list<int|string> $elementKey */
+    $elementKey = $form['#parents'];
+    FormValidationUtil::addFormErrorMapping($formState, $elementKey, array_merge($elementKey, ['value']));
+    FormValidationUtil::addKeepFormErrorElementKey($formState, array_merge($elementKey, ['format']));
+
+    FormCallbackRegistrator::registerPreSchemaValidationCallback(
+      $formState,
+      $definition->getFullScope(),
+      [HtmlCallbacks::class, 'convertValue'],
+      $form['#parents'],
+    );
+
+    return $form;
+  }
+
+  public function supportsDefinition(DefinitionInterface $definition): bool {
+    return $definition instanceof ControlDefinition && 'string' === $definition->getType()
+      && 'text/html' === $definition->getContentMediaType();
+  }
+
+}

src/Form/Util/FormValidationUtil.php

@@ -0,0 +1,83 @@
+<?php
+
+/*
+ * Copyright (C) 2025 SYSTOPIA GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace Drupal\json_forms\Form\Util;
+
+use Drupal\Core\Form\FormStateInterface;
+
+final class FormValidationUtil {
+
+  /**
+   * Allows to use a different form element to add a validation error than the
+   * JSON schema validation would use. Useful when a Drupal form element makes
+   * use of sub-elements, e.g. "text_format" uses the sub-elements "value" and
+   * "format" where "value" contains the value validated by the JSON schema. So
+   * validation errors detected by the JSON schema validator should be added to
+   * the "value" element.
+   *
+   * @param list<int|string> $key
+   *   Value of the "#parents" attribute.
+   * @param list<int|string> $targetKey
+   *   Value of the "#parents" attribute an error should be added to.
+   */
+  public static function addFormErrorMapping(FormStateInterface $formState, array $key, array $targetKey): void {
+    $formState->set(['formErrorMapping', implode('/', $key)], $targetKey);
+  }
+
+  /**
+   * @param list<int|string> $key
+   *
+   * @return list<int|string>
+   *   The element key ("#parents" attribute) an error for the element with the
+   *   given key should be added to. If no mapping is defined, the given key is
+   *   returned.
+   */
+  public static function getFormErrorMapping(FormStateInterface $formState, array $key): array {
+    // @phpstan-ignore return.type
+    return $formState->get(['formErrorMapping', implode('/', $key)]) ?? $key;
+  }
+
+  /**
+   * Allows to keep Drupal validation errors when the "$limitValidation" keyword
+   * is used. Normally, all Drupal validation errors are cleared when
+   * "$limitValidation" is used. This can be used to keep errors for fields that
+   * cannot be validated by the JSON schema, e.g. the "format" sub-element of a
+   * "text_format" element.
+   *
+   * @param list<int|string> $key
+   *   The form element key ("#parents" attribute) for which to keep Drupal
+   *   validation errors.
+   */
+  public static function addKeepFormErrorElementKey(FormStateInterface $formState, array $key): void {
+    $formState->set(['keepFormErrorElements', implode('/', $key)], $key);
+  }
+
+  /**
+   * @return list<list<int|string>>
+   *   List of element keys ("#parents" attribute) for which to keep Drupal
+   *   validation errors.
+   */
+  public static function getKeepFormErrorElementKeys(FormStateInterface $formState): array {
+    // @phpstan-ignore argument.type, return.type
+    return array_values($formState->get('keepFormErrorElements') ?? []);
+  }
+
+}

src/Form/Validation/FormValidationMapper.php

@@ -24,6 +24,7 @@
 use Assert\Assertion;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\json_forms\Form\Util\FieldNameUtil;
+use Drupal\json_forms\Form\Util\FormValidationUtil;
 use Drupal\json_forms\Form\Util\FormValueAccessor;
 use Opis\JsonSchema\JsonPointer;
 
@@ -40,8 +41,13 @@ public function mapErrors(ValidationResult $validationResult, FormStateInterface
     foreach ($validationResult->getLeafErrorMessages() as $pointer => $messages) {
       $pointer = JsonPointer::parse($pointer);
       Assertion::notNull($pointer);
-      // @phpstan-ignore-next-line
-      $element = ['#parents' => FieldNameUtil::toFormParents($pointer->absolutePath())];
+      $element = [
+        '#parents' => FormValidationUtil::getFormErrorMapping(
+          $formState,
+          // @phpstan-ignore argument.type
+          FieldNameUtil::toFormParents($pointer->absolutePath())
+        ),
+      ];
       $formState->setError($element, implode("\n", $messages));
     }
   }

src/JsonForms/Definition/Control/ControlDefinition.php

@@ -123,6 +123,10 @@ public function getConst() {
     return NULL;
   }
 
+  public function getContentMediaType(): ?string {
+    return $this->propertySchema->contentMediaType ?? NULL;
+  }
+
   public function getControlFormat(): ?string {
     return $this->controlSchema->options->format ?? NULL;
   }