function overlay_set_mode

Sets the overlay mode and adds proper JavaScript and styles to the page.

Note that since setting the overlay mode triggers a variety of behaviors (including hooks being invoked), it can only be done once per page request. Therefore, the first call to this function which passes along a value of the $mode parameter controls the overlay mode that will be used.

Parameters

$mode: To set the mode, pass in one of the following values:

• 'parent': This is used in the context of a parent window (a regular browser window). If set, JavaScript is added so that administrative links in the parent window will open in an overlay.
• 'child': This is used in the context of the child overlay window (the page actually appearing within the overlay iframe). If set, JavaScript and CSS are added so that Drupal behaves nicely from within the overlay.
• 'none': This is used to avoid adding any overlay-related code to the page at all. Modules can set this to explicitly prevent the overlay from being used. For example, since the overlay module itself sets the mode to 'parent' or 'child' in the overlay event subscriber when certain conditions are met, other modules which want to override that behavior can do so by setting the mode to 'none' earlier in the page request - e.g., in their own event subscribers, if they have a higher priority.

This parameter is optional, and if omitted, the current mode will be returned with no action taken.

Return value

The current mode, if any has been set, or NULL if no mode has been set.

See also

\Drupal\overlay\EventSubscriber\OverlaySubscriber::onRequest()

File

drupal/core/modules/overlay/overlay.module, line 546

Displays the Drupal administration interface in an overlay.

Code

function overlay_set_mode($mode = NULL) {
  global $base_path;
  $overlay_mode =& drupal_static(__FUNCTION__);

  // Make sure external resources are not included more than once. Also return
  // the current mode, if no mode was specified.
  if (isset($overlay_mode) || !isset($mode)) {
    return $overlay_mode;
  }
  $overlay_mode = $mode;
  switch ($overlay_mode) {
    case 'parent':
      drupal_add_library('overlay', 'drupal.overlay.parent');

      // Allow modules to act upon overlay events.
      module_invoke_all('overlay_parent_initialize');
      break;
    case 'child':
      drupal_add_library('overlay', 'drupal.overlay.child');

      // Allow modules to act upon overlay events.
      module_invoke_all('overlay_child_initialize');
      break;
  }
  return $overlay_mode;
}