81 lines
2.8 KiB
JavaScript
81 lines
2.8 KiB
JavaScript
/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim:set ts=2 sw=2 sts=2 et: */
|
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
'use strict';
|
|
|
|
module.metadata = {
|
|
"stability": "stable"
|
|
};
|
|
|
|
const { on, once, off } = require('./core');
|
|
const { method } = require('../lang/functional');
|
|
const { Class } = require('../core/heritage');
|
|
|
|
const EVENT_TYPE_PATTERN = /^on([A-Z]\w+$)/;
|
|
|
|
/**
|
|
* `EventTarget` is an exemplar for creating an objects that can be used to
|
|
* add / remove event listeners on them. Events on these objects may be emitted
|
|
* via `emit` function exported by 'event/core' module.
|
|
*/
|
|
const EventTarget = Class({
|
|
/**
|
|
* Method initializes `this` event source. It goes through properties of a
|
|
* given `options` and registers listeners for the ones that look like an
|
|
* event listeners.
|
|
*/
|
|
initialize: function initialize(options) {
|
|
options = options || {};
|
|
// Go through each property and registers event listeners for those
|
|
// that have a name matching following pattern (`onEventType`).
|
|
Object.keys(options).forEach(function onEach(key) {
|
|
let match = EVENT_TYPE_PATTERN.exec(key);
|
|
let type = match && match[1].toLowerCase();
|
|
let listener = options[key];
|
|
|
|
if (type && typeof(listener) === 'function')
|
|
this.on(type, listener);
|
|
}, this);
|
|
},
|
|
/**
|
|
* Registers an event `listener` that is called every time events of
|
|
* specified `type` are emitted.
|
|
* @param {String} type
|
|
* The type of event.
|
|
* @param {Function} listener
|
|
* The listener function that processes the event.
|
|
* @example
|
|
* worker.on('message', function (data) {
|
|
* console.log('data received: ' + data)
|
|
* })
|
|
*/
|
|
on: method(on),
|
|
/**
|
|
* Registers an event `listener` that is called once the next time an event
|
|
* of the specified `type` is emitted.
|
|
* @param {String} type
|
|
* The type of the event.
|
|
* @param {Function} listener
|
|
* The listener function that processes the event.
|
|
*/
|
|
once: method(once),
|
|
/**
|
|
* Removes an event `listener` for the given event `type`.
|
|
* @param {String} type
|
|
* The type of event.
|
|
* @param {Function} listener
|
|
* The listener function that processes the event.
|
|
*/
|
|
removeListener: function removeListener(type, listener) {
|
|
// Note: We can't just wrap `off` in `method` as we do it for other methods
|
|
// cause skipping a second or third argument will behave very differently
|
|
// than intended. This way we make sure all arguments are passed and only
|
|
// one listener is removed at most.
|
|
off(this, type, listener);
|
|
}
|
|
});
|
|
exports.EventTarget = EventTarget;
|