1. A computer-implemented method for invoking event handlers, the computer-implemented method comprising performing computer-implemented operations for: detecting an operation on application data associated with application metadata; in response to detecting the operation on the application data, determining if the application metadata comprises data describing one or more event handlers associated with the operation on the application data; and in response to determining that the application metadata comprises the data describing the one or more event handlers, identifying the one or more event handlers and invoking the one or more event handlers.