The receiver's delegate or nil if it doesn't have a delegate.
@property (nonatomic, weak) id<FBSDKAppGroupJoinDialogDelegate> delegate;
The ID for group.
@property (nonatomic, copy) NSString *groupID;
Convenience method to build up an app group dialog with content and a delegate.
The ID for the group.
The receiver's delegate.
A Boolean value that indicates whether the receiver can initiate an app group dialog.
May return NO if the appropriate Facebook app is not installed and is required or an access token is required but not available. This method does not validate the content on the receiver, so this can be checked before building up the content.
Begins the app group dialog from the receiver.
Validates the content on the receiver.
If an error occurs, upon return contains an NSError object that describes the problem.
validateWithError:(NSError *__autoreleasing *)errorRef;