handler.md

Format of Handler

An event handler which is passed to the method add() can take one of the following formats.

Function

The function that is called directly.

emitter.add("event", function (e) {
    console.log("I am event handler");
});

The function takes a single argument Event object. The this inside the function is NULL.

Array

The numeric list with 2 or 3 elements:

• {Object} - thisArg
• {Function|string} - a method or a method name
• {any[]} - bound arguments

Examples:

• [object, method] is method.call(object, event)
• [object, "method"] is object.method(event)
• [object, "method", [1, 2, 3]] is object.method(1, 2, 3, event)

Method by name computed each time.

var obj = {
    method: function () {
        console.log("one");
    }
};

emitter.add([obj, "method"]);
emitter.emit(e); // "one"

obj.method = function () {
    console.log("two");
};

emitter.emit(e); // "two"

Returns value

If a handler returns FALSE it is the same as e.preventDefault() and e.stopPropagation(). See Event object.