javascript - 有没有办法从 Jquery Deferred/Promise 到 When-JS Promise

Question

我想在 jquery ajax 调用返回的 promise 之外使用 When-JS 功能。有转换方案吗？

编辑 1

https://github.com/cujojs/when/blob/master/docs/api.md#api

Answer 1

是的，Promises/A+ promises 就像 When promises 具有这种设计的功能，它们是为了吸收 jQuery thenables 而构建的。

为了将任何外部 thenable(如 jQuery promise)转换为 when promise，只需将其包装在 when 中即可。 :

when($.get(...)).then(...

when(x) - get a trusted promise for x. If x is a foreign thenable, a returns a promise that follows x.

thenables 如何被同化 在 the Promises/A+ 中有详细说明。规范:

The promise resolution procedure is an abstract operation taking as input a promise and a value, which we denote as [[Resolve]](promise, x). If x is a thenable, it attempts to make promise adopt the state of x, under the assumption that x behaves at least somewhat like a promise. Otherwise, it fulfills promise with the value x.