website/static/bower_components/lunr.js/lib/event_emitter.js

83 lines
2.2 KiB
JavaScript

/*!
* lunr.EventEmitter
* Copyright (C) @YEAR Oliver Nightingale
*/
/**
* lunr.EventEmitter is an event emitter for lunr. It manages adding and removing event handlers and triggering events and their handlers.
*
* @constructor
*/
lunr.EventEmitter = function () {
this.events = {}
}
/**
* Binds a handler function to a specific event(s).
*
* Can bind a single function to many different events in one call.
*
* @param {String} [eventName] The name(s) of events to bind this function to.
* @param {Function} fn The function to call when an event is fired.
* @memberOf EventEmitter
*/
lunr.EventEmitter.prototype.addListener = function () {
var args = Array.prototype.slice.call(arguments),
fn = args.pop(),
names = args
if (typeof fn !== "function") throw new TypeError ("last argument must be a function")
names.forEach(function (name) {
if (!this.hasHandler(name)) this.events[name] = []
this.events[name].push(fn)
}, this)
}
/**
* Removes a handler function from a specific event.
*
* @param {String} eventName The name of the event to remove this function from.
* @param {Function} fn The function to remove from an event.
* @memberOf EventEmitter
*/
lunr.EventEmitter.prototype.removeListener = function (name, fn) {
if (!this.hasHandler(name)) return
var fnIndex = this.events[name].indexOf(fn)
this.events[name].splice(fnIndex, 1)
if (!this.events[name].length) delete this.events[name]
}
/**
* Calls all functions bound to the given event.
*
* Additional data can be passed to the event handler as arguments to `emit`
* after the event name.
*
* @param {String} eventName The name of the event to emit.
* @memberOf EventEmitter
*/
lunr.EventEmitter.prototype.emit = function (name) {
if (!this.hasHandler(name)) return
var args = Array.prototype.slice.call(arguments, 1)
this.events[name].forEach(function (fn) {
fn.apply(undefined, args)
})
}
/**
* Checks whether a handler has ever been stored against an event.
*
* @param {String} eventName The name of the event to check.
* @private
* @memberOf EventEmitter
*/
lunr.EventEmitter.prototype.hasHandler = function (name) {
return name in this.events
}