码农干货系列【12】--Promise库Version3 - 【当耐特】
by 【当耐特】
at 2013-04-21 10:30:00
original http://www.cnblogs.com/iamzhanglei/archive/2013/04/21/3033564.html
代码：
var Promise = function () { this.thens = [] }; Promise.prototype = { resolve: function () { this._handle("done", arguments) }, reject: function () { this._handle("fail", arguments) }, _handle: function (n, t) { var o, s, f, h, r, u, e, c, i; if (this.promiseArr) { for (i = 0, u = this.promiseArr.length; i < u; i++) this.promiseArr[i].resolveCount++; if (this.resolveCount !== this.promiseArr.length && n === "done") return; } while (o = this.thens.shift()) { if (f = o.done, h = o.fail, n === "fail") { h && h.apply(null, t); break; } if (f.length) { for (r = [], i = 0, u = f.length; i < u; i++) e = f[i].apply(null, t), e instanceof Promise && (e.thens = this.thens, r.push(e)); if (c = r.length, c === 0) continue; else { for (i = 0; i < c; i++) r[i].promiseArr = r, r[i].resolveCount = 0; break; } } else { if (s = f.apply(null, t), s instanceof Promise) { s.thens = this.thens; break; } continue; } } }, then: function (n, t) { this.thens.push({ done: n, fail: t }); return this; } }
更新：
去除了when方法，统一使用then,用then的第一个参数类型区分是单task还是多task
增加reject方法，处理task失败
使用：
f1() .then(function () { console.log(arguments) return f2(); }) .then(function () { f3(); }) .then(f4) .then(f5) .then(f6) .then(f7) .then([f8, f9, f10]) .then(f11, function () { console.log("fail"); }) function f1() { var promise = new Promise(); setTimeout(function () { console.log(1); promise.resolve("from f1"); }, 1500) return promise; } function f2() { var promise = new Promise(); setTimeout(function () { console.log(2); promise.resolve(); }, 2500) return promise; } function f3() { var promise = new Promise(); setTimeout(function () { console.log(3); promise.resolve(); }, 1500) return promise; } function f4() { var promise = new Promise(); setTimeout(function () { console.log(4); promise.resolve(); }, 1500) return promise; } function f5() { var promise = new Promise(); setTimeout(function () { console.log(5); promise.resolve(); }, 1500) return promise; } function f6() { console.log(6); } function f7() { var promise = new Promise(); setTimeout(function () { console.log(7); promise.resolve(); }, 1500) return promise; } function f8() { var promise = new Promise(); setTimeout(function () { console.log(8); promise.resolve(); }, 1500) return promise; } function f9() { var promise = new Promise(); setTimeout(function () { console.log(9); promise.resolve(); }, 5500) return promise; } function f10() { var promise = new Promise(); setTimeout(function () { console.log(10); promise.reject(); }, 1500) return promise; } function f11() { var promise = new Promise(); setTimeout(function () { console.log(11); promise.resolve(); }, 1500) return promise; }
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