jQuery的延迟 - 我需要管道或链来实现这种模式？ [英] jQuery deferred - do I need pipes or chains to achieve this pattern?

问题描述

我想实现如下因素的情况下，使用JQuery推迟，没有多少运气。

I'm trying to implement the folowing scenario, using JQuery deferred, without much luck.

你会用哪些部分递延API，以及你将如何构建你的电话来实现以下目标：

What parts of the deferred api would you use, and how would you structure your calls to achieve the following:

1日AJAX的马蹄莲以serviceA找回ID列表

1st ajax callA to serviceA retrieve a list of Ids

等待，直到此调用返回

则n AJAX调用serviceB，每个呼叫使用使用ID由马蹄莲返回列表

then n ajax calls to serviceB, each call using a using an Id from the list returned by callA

等待，直到所有serviceB调用已经返回

wait until all serviceB calls have returned

那么最终的Ajax调用serviceC

then a final ajax call to serviceC

推荐答案

您可以做这样的（或多或少伪code）：

You could do like this (more or less pseudocode):

(function() {
    // new scope
    var data = []; // the ids coming back from serviceA

    var deferredA = callToServiceA(data); // has to add the ids to data

    deferredA.done(function() { // if callToServiceA successful...
        var deferredBs = [];

        for i in data {
            deferredBs.push(callToServiceB(...));
        }

        $.when.apply($, deferredBs).then(callToServiceC); 
    });

}());

在 callToServiceX 函数返回由 $返回的承诺对象。AJAX 。

有可能是一个干净的解决方案不是让数据在一个共享的范围，用的 决心 ，但是设置会更有点困难（​​不一定更具可读性）。

There might be a "cleaner" solution than having data in a shared scope, with resolve, but the setup would be a bit more difficult (and not necessarily more readable).

这篇关于jQuery的延迟 - 我需要管道或链来实现这种模式？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！