result = None if self.task.on_open: result = self.task.on_open(self, params) if result is None and self.on_open: result = self.on_open(self, params) if result is None: result = self.execute_open(params)
It checks if the task has an
on_open event handler. If the
event handler is declared in the task server module, it is executed.
on_open event handler of the task is not declared or the result
of the event handler returns
None, the method checks whether the item has an
event handler. If it is declared in the item server module, it is executed.
If the result returned by the item event handler is
execute_open method of the item is called that generates SQL query,
execute it and returns the result