PHProjectTypeDescriptionDataSource
A protocol that you use to provide the project with type description data.
Declaration
protocol PHProjectTypeDescriptionDataSource : NSObjectProtocolOverview
An object adheres to this protocol to provide a type description for your app’s Photos project extension. You must implement this protocol to provide subtypes, a description, and footer text. You can optionally respond to the system discarding the data source by implementing extensionWillDiscardDataSource().