I need to be able to start the authentication process in this sample without pressing the button provided by default.
The action I want to run is the -(void)buttonPressed method, but if I try to invoke it manually the plugin crashes. It's invoked automatically by pressing that button but it would be nice to be able to just press enter.
This should all be obvious after a single glance in the plugin source code you linked!
While it shouldn't crash (after a quick look into the class code), you probably do not supply the appropriate sender when sending buttonPressed: from your code. The method is defined as
- (void)buttonPressed:(SFButtonType)inButtonType
Which clearly shows the button that was pressed is given as sender. So in your code when calling buttonPressed:
do for example like:
["referenceRToClass" buttonPressed:SFButtonTypeOK];