管理XHR承诺

Question

所以我一直在考虑将XHR包装在Promise中。我遇到的问题是管理它们。有没有办法可以在Promise的 .then（）中管理请求，而不是在Promise本身内部？

var i = 0;
var requests = [];
while(i < 10) {

  mkPromise().then(function (response) {
    console.log(response) // handle fulfilled requests
  })
    .catch(function (error) {
    console.log(error)
  })
    .then(function (response) {
    console.log(requests) // manage requests here
  });

  i++
}


function mkPromise () {
  var url = 'http://example.com';

  return new Promise(function(resolve, reject) {

    // Do the usual XHR stuff
    var req = new XMLHttpRequest();
    req.open('GET', url);
    req.setRequestHeader("Content-Type", "application/json;charset=UTF-8");

    req.onload = function() {
      // This is called even on 404 etc
      // so check the status
      if (req.status == 200) {
        // Resolve the promise with the response text
        resolve(req.response);

        // Do this in the final .then() instead of here so that it's managed for errors as well without duplicating removal process
        var index = requests.indexOf(req);
        requests.splice(index,1)
      }
      else {
        // Otherwise reject with the status text
        // which will hopefully be a meaningful error
        reject(Error(req.statusText));
      }
    };

    // Handle network errors
    req.onerror = function() {
      reject(Error("Network Error"));
    };

    requests.push(req)
    // Make the request
    req.send();
  });
}