| ; | |
| /* | |
| global window, | |
| document, | |
| app | |
| */ | |
| (function() { | |
| // check if the app itself is defined at all | |
| if (! app) { | |
| return console.error('[modules/events] app.js has not been loaded yet'); | |
| } | |
| // create the module object | |
| var eventModule = { | |
| events: {} | |
| }; | |
| /** | |
| * on function. | |
| * adds a callback to an event stack | |
| * | |
| * @param {string} type the event to subscribe to | |
| * @param {function} callback the event callback to subscribe | |
| * | |
| * @return void | |
| */ | |
| eventModule.on = function(type, callback) { | |
| // if there is no callback registered for this event yet, create an array for this event | |
| if (! this.events.hasOwnProperty(type)) { | |
| this.events[ type ] = []; | |
| } | |
| // push the event callback to the handler stack | |
| this.events[ type ].push(callback); | |
| }; | |
| /** | |
| * off function. | |
| * removes a callback from an event stack | |
| * | |
| * @param {string} type the event to unsubscribe from | |
| * @param {function} callback the event callback to unsubscribe | |
| * | |
| * @return {boolean} whether the callback was removed or not | |
| */ | |
| eventModule.off = function(type, callback) { | |
| // if the event does not exist, return false | |
| if (! type in this.events) { | |
| return false; | |
| } | |
| // if no callback to unsubscribe was given, remove all callbacks | |
| if (typeof callback === 'undefined') { | |
| return delete this.events[ type ]; | |
| } | |
| // iterate over handlers, remove the callback in question | |
| this.events[ type ] = this.events[ type ].filter( | |
| function(item) { | |
| if (item !== callback) { | |
| return item; | |
| } | |
| } | |
| ); | |
| return true; | |
| }; | |
| /** | |
| * emit function. | |
| * calls all registered callbacks for an event | |
| * | |
| * @param {string} type the event to trigger callbacks for | |
| * @param {*} [data] optional data to hand over to the callbacks | |
| * @param {*} [context] optional context to hand over to the callbacks, | |
| * defaults to window | |
| * | |
| * @return {boolean} whether the event has been fired | |
| */ | |
| eventModule.emit = function(type, data, context) { | |
| // use an empty object if no data given | |
| data = data || {}; | |
| // use window as the context if no context given | |
| context = context || window; | |
| // the event does not exist. | |
| if (! this.events.hasOwnProperty(type)) { | |
| return false; | |
| } | |
| // iterate over all callbacks, run them as expected | |
| for (var i = 0; i < this.events[ type ].length; i++) { | |
| this.events[ type ][ i ].call(context, type, data); | |
| } | |
| return true; | |
| }; | |
| /** | |
| * getEvents function. | |
| * returns all registered events. | |
| * | |
| * @return {Array} the list of events | |
| */ | |
| eventModule.getEvents = function () { | |
| var events = []; | |
| for (var event in this.events) { | |
| if (! this.events.hasOwnProperty(event)) continue; | |
| events.push(event); | |
| } | |
| return events; | |
| }; | |
| // register the module in the app | |
| app.registerModule('events', eventModule, function() { | |
| // register event endpoints | |
| app.mountModuleEndpoint('on', 'events', 'on'); | |
| app.mountModuleEndpoint('off', 'events', 'off'); | |
| app.mountModuleEndpoint('emit', 'events', 'emit'); | |
| }); | |
| // return the module | |
| return eventModule; | |
| })(); | |