var eventEmitter = {
functionList: {},
oneFunctionList: {},
on: function (type, fn) {
if (!Array.isArray(this.functionList[type])) {
this.functionList[type] = [];
}
this.functionList[type].push(fn);
},
one: function (type, fn) {
if (!Array.isArray(this.oneFunctionList[type])) {
this.oneFunctionList[type] = [];
}
this.oneFunctionList[type].push(fn);
},
remove: function (type) {
this.functionList[type] = [];
this.oneFunctionList[type] = [];
},
fire: function (type) {
if (this.functionList.hasOwnProperty(type)) {
this.functionList[type].forEach(fn => {
fn.apply(null, [].slice.call(arguments, 1));
});
} else if (this.oneFunctionList.hasOwnProperty(type)) {
this.oneFunctionList[type].forEach((fn, index) => {
fn.apply(null, [].slice.call(arguments, 1));
this.oneFunctionList[type].splice(index, 1);
} else {
console.log(‘no listeners‘);
}
}
}
实现一个eventEmitter
原文：https://www.cnblogs.com/dragon-cat/p/9490679.html
