对没有全局变量的多个事件使用promise回调 [英] Using promise callbacks for multiple events without global variables

问题描述

我有一个函数包含的承诺。我将使用不同的输入参数多次调用此函数。每次promise都解析后，我将解析后的值推送到存储数组中。

I have a promise wrapped in a function. I will call this function multiple times using different input parameters. Each time the promise resolves I push the resolved value into a storage array.

当我所有的被叫Promise都已解决后，我将在其他函数中使用这个存储数组。

When all my called promises have resolved I will then use this storage array in other functions.

如果有任何干净的方法来设置它而不使用global-ish变量？

If there any clean way to set this up without using "global-ish" variables?

以下代码是我能想到的唯一方法：

The code below is the only way I can think of to make this work:

// Set global-ish variables that can be referenced from multiple functions
var storageArray = [];
var numberOfPromiseCalls = 10;
var promiseCallsCount = 0;

// Setup promise wrapper
function promiseWrapper(inputParams){
  return new Promise(function(resolve, reject) {
    // awesome stuff at work here using inputParams
    resolve(desiredOutput);
  }
})

// call promise 10 times
for(i=0;i<numberOfPromiseCalls;i++){

  // actual promise call
  promiseWrapper(inputParams[i]).then(function (desiredOutput) {

    // push resolve to storage array
    storageArray.push(desiredOutput);

    // test if this resolve is the "last" resolve of all the promises we called
    promiseCallsCount++;
    if(promiseCallsCount == numberOfPromiseCalls){

      // ************************
      // call a function that can work with the final storageArray
      // ************************

    }
  })
}

我的意思是，上面的代码有效，但男人觉得很难看。存在很多歧义，你需要跟踪变量层次结构。有没有更好的方法呢？

I mean, the code above works, but man it feels ugly. There's a lot of ambiguity going on and variable hierarchy's you have to keep track of. Is there any better way of doing this?

推荐答案

我建议您使用 Promise.all 传递一系列承诺。调用然后将允许您在所有承诺得到解决后处理所有响应。

I would suggest you using of Promise.all with passing an array of your promises. Invoking then will let you to handle all response when all of the promises are resolved.

参考： https://developer.mozilla.org/en-US / docs / Web / JavaScript / Reference / Global_Objects / Promise / all

for (i=0;i<numberOfPromiseCalls;i++){
  storageArray.push(promiseWrapper(inputParams[i]));
}

Promise.all(storageArray).then(responses => {
  // responses is an array of all promises responses
});

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