等待所有承诺解决 [英] Wait for all promises to resolve

问题描述

所以我有一种情况，我有多个未知长度的承诺链.我希望在处理完所有 CHAINS 后运行一些操作.这甚至可能吗?下面是一个例子:

So I have a situation where I have multiple promise chains of an unknown length. I want some action to run when all the CHAINS have been processed. Is that even possible? Here is an example:

app.controller('MainCtrl', function($scope, $q, $timeout) {
    var one = $q.defer();
    var two = $q.defer();
    var three = $q.defer();

    var all = $q.all([one.promise, two.promise, three.promise]);
    all.then(allSuccess);

    function success(data) {
        console.log(data);
        return data + "Chained";
    }

    function allSuccess(){
        console.log("ALL PROMISES RESOLVED")
    }

    one.promise.then(success).then(success);
    two.promise.then(success);
    three.promise.then(success).then(success).then(success);

    $timeout(function () {
        one.resolve("one done");
    }, Math.random() * 1000);

    $timeout(function () {
        two.resolve("two done");
    }, Math.random() * 1000);

    $timeout(function () {
        three.resolve("three done");
    }, Math.random() * 1000);
});

在这个例子中，我为承诺一、二和三设置了一个 $q.all() ，这些承诺将在某个随机时间得到解决.然后我将 promise 添加到 1 和 3 的末尾.我希望 all 在所有链都被解析后解析.这是我运行此代码时的输出:

In this example, I set up a $q.all() for promises one, two, and three which will get resolved at some random time. I then add promises onto the ends of one and three. I want the all to resolve when all the chains have been resolved. Here is the output when I run this code:

one done 
one doneChained
two done
three done
ALL PROMISES RESOLVED
three doneChained
three doneChainedChained 

有没有办法等待链解决?

Is there a way to wait for the chains to resolve?

推荐答案

我希望在解决所有链后解决所有问题.

I want the all to resolve when all the chains have been resolved.

当然，那么只需将每个链的承诺传递到 all() 而不是最初的承诺:

Sure, then just pass the promise of each chain into the all() instead of the initial promises:

$q.all([one.promise, two.promise, three.promise]).then(function() {
    console.log("ALL INITIAL PROMISES RESOLVED");
});

var onechain   = one.promise.then(success).then(success),
    twochain   = two.promise.then(success),
    threechain = three.promise.then(success).then(success).then(success);

$q.all([onechain, twochain, threechain]).then(function() {
    console.log("ALL PROMISES RESOLVED");
});

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