ISSUE-274: Report render array output error in Metadata Display preview

format_strawberryfield.module

@@ -364,3 +364,31 @@ function format_strawberryfield_cron() {
 
 }
 
+/**
+ * Provides custom PHP error handling when processing ajax previews.
+ *
+ * Converts trigger_error() to WARNING so that an exceptions can be thrown
+ * and caught by
+ * \Drupal\format_strawberryfield\MetadataDisplayForm::ajaxPreview().
+ *
+ * @param int $error_level
+ * The level of the error raised.
+ * @param string $message
+ * The error message.
+ * @param string $filename
+ * (optional) The filename that the error was raised in.
+ * @param string $line
+ * (optional) The line number the error was raised at.
+ * @param array $context
+ * (optional) An array that points to the active symbol table at the point the
+ * error occurred.
+ *
+ * @throws \ErrorException
+ * Throw ErrorException for all errors passed from trigger_error().
+ *
+ * @see \Drupal\format_strawberryfield\MetadataDisplayForm::ajaxPreview()
+ */
+function _format_strawberryfield_metadata_preview_error_handler($error_level, $message, $filename = NULL, $line = NULL, $context = NULL) {
+ _drupal_error_handler(E_WARNING, $message, $filename, $line, $context);
+ throw new ErrorException($message, $error_level, 0, $filename, $line);
+}

src/Entity/MetadataDisplayEntity.php

@@ -4,6 +4,8 @@
 
 use Drupal\Core\Cache\Cache;
 use Twig\Node\ModuleNode;
+use Twig\Node\BodyNode;
+use Twig\Node\Node;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Field\BaseFieldDefinition;
 use Drupal\Core\Entity\ContentEntityBase;
@@ -402,6 +404,7 @@ public function renderNative(array $context) {
  $twigtemplate,
  $context
  );
+
  return $rendered;
  }
 
@@ -429,29 +432,35 @@ public function getTwigVariablesUsed() {
  * @param \Twig\Node\ModuleNode $nodes
  * A Twig Module Nodes object.
  *
+ * @param \Twig\Node\BodyNode $nodes
+ * A Twig Module Nodes object.
+ *
+ * @param \Twig\Node\Node $nodes
+ * A Twig Module Nodes object.
+ *
  * @return array
  * A list of used $variables by this template.
  */
- private function getTwigVariableNames(ModuleNode $nodes): array {
+ private function getTwigVariableNames(ModuleNode|Node|BodyNode $nodes): array {
  $variables = [];
  foreach ($nodes as $node) {
- if ($node instanceof \Twig_Node_Expression_Name) {
+ if ($node instanceof \Twig\Node\Expression\NameExpression) {
  $name = $node->getAttribute('name');
  $variables[$name] = $name;
  }
- elseif ($node instanceof \Twig_Node_Expression_Constant && $nodes instanceof \Twig_Node_Expression_GetAttr) {
+ elseif ($node instanceof \Twig\Node\Expression\ConstantExpression && $nodes instanceof \Twig\Node\Expression\GetAttrExpression) {
  $value = $node->getAttribute('value');
  if (!empty($value) && is_string($value)) {
  $variables[$value] = $value;
  }
  }
- elseif ($node instanceof \Twig_Node_Expression_GetAttr) {
+ elseif ($node instanceof \Twig\Node\Expression\GetAttrExpression) {
  $path = implode('.', $this->getTwigVariableNames($node));
  if (!empty($path)) {
  $variables[$path] = $path;
  }
  }
- elseif ($node instanceof \Twig_Node) {
+ elseif ($node instanceof \Twig\Node\Node) {
  $variables += $this->getTwigVariableNames($node);
  }
  }

src/Form/MetadataDisplayForm.php

@@ -178,11 +178,13 @@ public function save(array $form, FormStateInterface $form_state) {
  * AJAX callback.
  */
  public static function ajaxPreview($form, FormStateInterface $form_state) {
+ set_error_handler('_format_strawberryfield_metadata_preview_error_handler');
  $response = new AjaxResponse();
 
  /** @var \Drupal\format_strawberryfield\MetadataDisplayInterface $entity */
  $entity = $form_state->getFormObject()->getEntity();
 
+ $used_vars = $entity->getTwigVariablesUsed();
  // Attach the library necessary for using the OpenOffCanvasDialogCommand and
  // set the attachments for this Ajax response.
  $form['#attached']['library'][] = 'core/drupal.dialog.off_canvas';
@@ -252,6 +254,31 @@ public static function ajaxPreview($form, FormStateInterface $form_state) {
  'mode' => 'application/json',
  ],
  ];
+ sort($used_vars);
+ $json_keys = array_keys($jsondata);
+ $data_json = array_map(function($key) {
+ return 'data.' . $key;
+ }, $json_keys);
+ $unused_vars = array_diff($data_json,$used_vars);
+ sort($unused_vars);
+ $used_rows = array_map(function($used) {
+ return [$used];
+ }, $used_vars);
+ $unused_rows = array_map(function($unused) {
+ return [$unused];
+ }, $unused_vars);
+ $var_table = [
+ '#type' => 'table',
+ '#header' => [t('Used Variables')],
+ '#rows' => $used_rows,
+ '#empty' => t('No content has been found.'),
+ ];
+ $json_table = [
+ '#type' => 'table',
+ '#header' => [t('Unused JSON keys')],
+ '#rows' => $unused_rows,
+ '#empty' => t('No content has been found.'),
+ ];
 
  // Try to Ensure we're using the twig from user's input instead of the entity's
  // default.
@@ -337,6 +364,22 @@ public static function ajaxPreview($form, FormStateInterface $form_state) {
  ],
  ];
  }
+ $output['twig_vars'] = [
+ '#type' => 'details',
+ '#open' => FALSE,
+ '#title' => 'Twig Variables',
+ 'render' => [
+ 'table' => $var_table
+ ],
+ ];
+ $output['json_unused'] = [
+ '#type' => 'details',
+ '#open' => FALSE,
+ '#title' => 'Unused JSON keys',
+ 'render' => [
+ 'table' => $json_table
+ ],
+ ];
  } catch (\Exception $exception) {
  // Make the Message easier to read for the end user
  if ($exception instanceof TwigError) {
@@ -354,7 +397,25 @@ public static function ajaxPreview($form, FormStateInterface $form_state) {
  '#markup' => $message,
  ]
  ];
+ $output['twig_vars'] = [
+ '#type' => 'details',
+ '#open' => FALSE,
+ '#title' => 'Twig Variables',
+ 'render' => [
+ 'table' => $var_table
+ ],
+ ];
+ $output['json_unused'] = [
+ '#type' => 'details',
+ '#open' => FALSE,
+ '#title' => 'Unused JSON keys',
+ 'render' => [
+ 'table' => $json_table
+ ],
+ ];
  }
+ restore_error_handler();
+ restore_exception_handler();
  $response->addCommand(new OpenOffCanvasDialogCommand(t('Preview'), $output, ['width' => '50%']));
  }
  // Always refresh the Preview Element too.