function field_ui_menu_load in Drupal 7

Menu loader; Load a field instance based on field and bundle name.

Parameters

$field_name: The name of the field, as contained in the path.

$entity_type: The name of the entity.

$bundle_name: The name of the bundle, as contained in the path.

$bundle_pos: The position of $bundle_name in $map.

$map: The translated menu router path argument map.

Return value

The field instance array.

Related topics

File

modules/field_ui/field_ui.module, line 231

Allows administrators to attach custom fields to fieldable types.

Code

function field_ui_menu_load($field_name, $entity_type, $bundle_name, $bundle_pos, $map) {

  // Extract the actual bundle name from the translated argument map.
  // The menu router path to manage fields of an entity can be shared among
  // multiple bundles. For example:
  // - admin/structure/types/manage/%node_type/fields/%field_ui_menu
  // - admin/structure/types/manage/%comment_node_type/fields/%field_ui_menu
  // The menu system will automatically load the correct bundle depending on the
  // actual path arguments, but this menu loader function only receives the node
  // type string as $bundle_name, which is not the bundle name for comments.
  // We therefore leverage the dynamically translated $map provided by the menu
  // system to retrieve the actual bundle and bundle name for the current path.
  if ($bundle_pos > 0) {
    $bundle = $map[$bundle_pos];
    $bundle_name = field_extract_bundle($entity_type, $bundle);
  }

  // Check whether the field exists at all.
  if ($field = field_info_field($field_name)) {

    // Only return the field if a field instance exists for the given entity
    // type and bundle.
    if ($instance = field_info_instance($entity_type, $field_name, $bundle_name)) {
      return $instance;
    }
  }
  return FALSE;
}