Core class used to implement the Navigation Menu widget.

Sets up a new Navigation Menu widget instance.

Outputs the settings form for the Navigation Menu widget.

Handles updating settings for the current Navigation Menu widget instance.

Outputs the content for the current Navigation Menu widget instance.

Sets the list of global cache groups.

Resets cache keys.

Fetches result from an oEmbed provider for a specific format and complete provider URL

Parses a json response body.

Parses an XML response body.