handle_event()

Syntax

handle_event(event, function, ...args)

Provides a handler for an event identified by the ‘event’ argument. If the event doesn’t exist yet, it will be created. All loaded apps globally can trigger that event, when they call corresponding signal_event(event, ...). Callback can be defined as a function name, function value (or a lambda function), along with optional extra arguments that will be passed to it when the event is triggered. All custom events expect a function that takes one free argument, passed by the event trigger. If extra arguments are provided, they will be appended to the argument list of the callback function.

Returns true if subscription to the event was successful, or false if it failed (for instance wrong scope for built-in event, or incorrect number of parameters for the event).

If a callback is specified as null, the given app (or player app instance )stops handling that event.

foo(a) -> print(a);
handle_event('boohoo', 'foo');

bar(a, b, c) -> print([a, b, c]);
handle_event('boohoo', 'bar', 2, 3) // using b = 2, c = 3, a - passed by the caller

handle_event('tick', _() -> foo('tick happened')); // built-in event

handle_event('tick', null);  // nah, ima good, kthxbai

In case you want to pass an event handler that is not defined in your module, please read the tips on “Passing function references to other modules of your application” section in the call(...) section.