public function deleteExistingObject(NodeInterface $node, Context $context, $dirtyAllowed = false)
 {
     /* @var $node FieldInstanceNode */
     $existing = field_info_instance($node->getEntityType(), $node->getName(), $node->getBundle());
     if (!$existing) {
         $context->logWarning(sprintf("%s: does not exists", $node->getPath()));
         return false;
     }
     field_delete_instance($existing);
 }
 public function synchronize(NodeInterface $node, Context $context, $dirtyAllowed = false)
 {
     /* @var $node ViewNode */
     $entityType = $node->getEntityType();
     $bundle = $node->getBundle();
     $name = $node->getName();
     // First populate the variable that will be used during the
     // hook_entity_info_alter() call to populate the view modes
     $viewModes = variable_get(USYNC_VAR_VIEW_MODE, []);
     $viewModes[$entityType][$name] = $name;
     variable_set(USYNC_VAR_VIEW_MODE, $viewModes);
     // First grab a list of everything that can be displayed in view
     // modes with both extra fields and real fields
     $instances = field_info_instances($entityType, $bundle);
     $bundleSettings = field_bundle_settings($entityType, $bundle);
     $extra = $this->getExtraFieldsDisplay($entityType, $bundle);
     $weight = 0;
     $displayExtra = [];
     $displayField = [];
     // Then deal with fields and such
     foreach ($node->getValue() as $propertyName => $formatter) {
         if (isset($instances[$propertyName])) {
             $display = array();
             // We are working with a field
             if (!is_array($formatter)) {
                 if (true === $formatter || 'default' === $formatter) {
                     $formatter = array();
                 } else {
                     if (false === $formatter || null === $formatter || 'delete' === $formatter) {
                         continue;
                     } else {
                         if (!is_string($formatter)) {
                             $context->logWarning(sprintf("%s: %s invalid value for formatter", $node->getPath(), $propertyName));
                             $formatter = array();
                         } else {
                             $display['type'] = $formatter;
                         }
                     }
                 }
             } else {
                 $display = $formatter;
             }
             // Merge default and save
             $displayField[$propertyName] = drupal_array_merge_deep($this->getFieldDefault($node, $entityType, $bundle, $propertyName, $context), $display, array('weight' => $weight++));
         } else {
             if (isset($extra[$propertyName])) {
                 // We are working with and extra field
                 if (!is_array($formatter)) {
                     if (true === $formatter || 'default' === $formatter) {
                         $formatter = array();
                     } else {
                         if (false === $formatter || null === $formatter || 'delete' === $formatter) {
                             continue;
                         } else {
                             $context->logWarning(sprintf("%s: %s extra fields can only be delete or default", $node->getPath(), $propertyName));
                         }
                     }
                 }
                 // Merge default and save
                 $displayExtra[$propertyName] = ['visible' => true, 'weight' => $weight++];
             } else {
                 $context->logError(sprintf("%s: %s property is nor a field nor an extra field", $node->getPath(), $propertyName));
             }
         }
     }
     // Iterate over the fields and update each instance: we don't
     // need to do it with the $displayExtra property since it is
     // already the correctly formatted variable
     foreach ($displayField as $fieldName => $display) {
         $instances[$fieldName]['display'][$name] = $display;
     }
     // Remove non configured fields and extra fields from display
     foreach ($instances as $fieldName => $instance) {
         if (!isset($displayField[$fieldName])) {
             $instance['display'][$name] = array('type' => 'hidden');
         }
         if ($dirtyAllowed) {
             $data = $instance;
             unset($data['id'], $data['field_id'], $data['field_name'], $data['entity_type'], $data['bundle'], $data['deleted']);
             db_update('field_config_instance')->condition('id', $instance['id'])->fields(['data' => serialize($data)])->execute();
         } else {
             field_update_instance($instance);
         }
     }
     foreach (array_keys($extra) as $propertyName) {
         if (isset($displayExtra[$propertyName])) {
             $bundleSettings['extra_fields']['display'][$propertyName][$name] = $displayExtra[$propertyName];
         } else {
             $bundleSettings['extra_fields']['display'][$propertyName][$name] = ['visible' => false, 'weight' => $weight++];
         }
     }
     $bundleSettings['view_modes'][$name] = ['label' => $name, 'custom_settings' => true];
     if ($dirtyAllowed) {
         // Hopefully nothing about display is really cached into the
         // internal field cache class, except the raw display array
         // into each instance, but nothing will use that except this
         // specific view mode implementation, we are going to delay
         // a few cache clear calls at the very end of the processing.
         // From field_bundle_settings().
         variable_set('field_bundle_settings_' . $entityType . '__' . $bundle, $bundleSettings);
     } else {
         field_bundle_settings($entityType, $bundle, $bundleSettings);
     }
     if ($dirtyAllowed) {
         // From field_update_instance()
         cache_clear_all('*', 'cache_field', true);
         // From field_info_cache_clear()
         drupal_static_reset('field_view_mode_settings');
         // We need to clear cache in order for later view modes to
         // load the right instance and prevent them for overriding
         // what we actually did here
         entity_info_cache_clear();
         _field_info_field_cache()->flush();
     }
 }