Merge pull request #347 from aksm/ISSUE-338b

ISSUE-338: Custom error handler needs to filter out unhelpful errors/deprecations

Author: DiegoPino

format_strawberryfield.module

@@ -367,9 +367,10 @@ 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
+ * Throws exceptions for E_USER_WARNING and E_USER_ERROR only
+ * to be caught by
  * \Drupal\format_strawberryfield\MetadataDisplayForm::ajaxPreview().
+ * All other errors are passed back to Drupal's error handler.
  *
  * @param int $error_level
  *   The level of the error raised.
@@ -384,11 +385,19 @@ function format_strawberryfield_cron() {
  *   error occurred.
  *
  * @throws \ErrorException
- *   Throw ErrorException for all errors passed from trigger_error().
+ *   Throw ErrorException for E_USER_WARNING and E_USER_ERROR only.
  *
  * @see \Drupal\format_strawberryfield\MetadataDisplayForm::ajaxPreview()
  */
 function _format_strawberryfield_metadata_preview_error_handler($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, $line);
+    switch($error_level)
+    {
+      case E_USER_WARNING:
+      case E_USER_ERROR:
+        _drupal_error_handler($error_level, $message, $filename, $line, $context);
+        throw new ErrorException($message, $error_level, 0, $filename, $line);
+      default:
+        _drupal_error_handler($error_level, $message, $filename, $line, $context);
+        break;
+    }
 }

src/Form/MetadataDisplayForm.php

@@ -286,6 +286,10 @@ public static function ajaxPreview($form, FormStateInterface $form_state) {
       $mimetype = !empty($mimetype) ? $mimetype[0]['value'] : 'text/html';
       $show_render_native = $form_state->getValue('render_native');
 
+      if ($show_render_native) {
+        set_error_handler('_format_strawberryfield_metadata_preview_error_handler');
+      }
+
       $sbf_fields = \Drupal::service('strawberryfield.utility')
         ->bearsStrawberryfield($preview_node);
 
@@ -437,6 +441,9 @@ public static function ajaxPreview($form, FormStateInterface $form_state) {
 
 	}
       }
+      if ($show_render_native) {
+        restore_error_handler();
+      }
       $response->addCommand(new OpenOffCanvasDialogCommand(t('Preview'), $output, ['width' => '50%']));
     }
     // Always refresh the Preview Element too.