function NewPromise (fn) {
this.state = 'pending'
this.fulfillList = []
this.rejectList = []
fn(this.resolve.bind(this), this.reject.bind(this))
// 成功执行成功的队列
}
NewPromise.prototype.resolve = function (data) {
this.state = 'fulfilled'
var args = [].slice.call(arguments)
setTimeout(function() {
this.fulfillList.forEach(function ( itemFn, key, arr) {
itemFn.apply(null, args)
arr.shift()
})
}.bind(this), 0)
} //失败 执行失败的队列
NewPromise.prototype.reject = function (data) {
this.state = 'rejected'
var args2 = [].slice.call(arguments)
setTimeout(function() {
this.rejectList.forEach(function ( itemFn, key, arr) {
itemFn.apply(null, args2)
arr.shift()
})
}.bind(this), 0)
}
//成功的回调函数
NewPromise.prototype.done = function (handle) {
if(typeof handle === 'function') {
this.fulfillList.push(handle)
} else {
throw new Error('回调出错')
return this
}
}
// 失败的回调函数
NewPromise.prototype.fail = function (handle) {
if(typeof handle === 'function') {
this.rejectList.push(handle)
} else {
throw new Error('回调出错')
return this
}
}
NewPromise.prototype.then = function (fulfiil, reject) {
this.done( fulfill ) || function () {}
.fail(reject) || function () {}
return this
}
NewPromise.prototype.always = function (handle) {
this.done(handle) || function () {}
.fail(handle) || function () {}
return this
}
var prm = NewPromise(function (resolve, reject) {
setTimeout(function () {
resolve('成功的参数')
reject('失败的参数')
}, 1000)
})
prm.then(function (data) {
console.log(data)
}).fail(function (data) {
console.log(data)
})
