Poll: Syntax for returning event handlers with args

[picklelo]

We have a couple solutions for issue #876

Currently the class attribute State.event_handler is of type EventHandler while the object attribute self.event_handler is the raw function that the event handler wraps.

When returning event handlers from other event handlers to add to the queue we have a couple of options.

Option 1:

• Within event handlers, self. refers to the function, and State. refers to the EventHandler object.
• To call a function within an event handler, do self.other_handler()
• When returning event handlers to State.other_handler(arg)

class State(pc.State):
    """The app state."""

    def fn_no_arg(self):
       ...

    def fn_multi_arg(self, arg1, arg2):
       ...

    def f1(self):
        # Call the function using `self.`
        self.fn_no_arg()
        # Return event handler using `State.`
        return State.fn_no_arg
        # This is valid also.
        return State.fn_no_arg()

    def f2(self):
        self.fn_multi_arg(1, 2)
        return State.fn_multi_arg(1, 2)

Option 2:

• Within event handlers, only use self. never State.
• To call a function within an event handler, do self.other_handler()
• When returning event handlers with args, use a lambda

class State(pc.State):
    """The app state."""

    def fn_no_arg(self):
       ...

    def fn_multi_arg(self, arg1, arg2):
       ...

    def f1(self):
        # Call the function using `self.`
        self.fn_no_arg()
        # Return event handler using `self.`
        return self.fn_no_arg
        # This is valid also.
        return lambda: self.fn_no_arg()

    def f2(self):
        self.fn_multi_arg(1, 2)
        # For arguments, return a lambda.
        return lambda: self.fn_multi_arg(1, 2)

[picklelo]

Thanks for the feedback! Since Option 1 is already implemented, we will update the docs for that first. Later we can add Option 2 if people want.