2daba54b_Plugin_API_usPlugin__redefinable_methods__Explanation
[Method Signature] doAction($type) [Explanation] 
When a plugin wants to allow user interaction, it can allow actions through action.php. This is the script that Nucleus uses itself to handle new comments and karma votes. Called with the correct parameters, the doAction-method from a plugin can be called. The $type contains an optional message type. Extra variables from the request can be accessed from within the doAction method. By default, this method returns a string No Such Action which will trigger an error message. More info on doAction.
Plugin API
Explanation