运行请求,直到响应是$ q

时间:2015-11-05 09:50:27

标签: javascript angularjs promise q deferred

我有这个说明我的问题:

http://plnkr.co/edit/tsBy2K0xv6bboBlZRM8c

$scope.start = function() {

  runThisUntil("Ok");
  //here I would like to do this:
  //runThisUntil("Ok").then(function () {
  //doSomeStuff()  
  //});

}

$scope.clear = function() {
  $scope.responses = [];
}

function runThisUntil(criteria) {

  runThis(criteria);



}

function runThis(criteria) {
  run().then(function (response) {
    if (response == criteria) {
      $scope.responses.push("Done");
    } else {
      $scope.responses.push("Wait");
      runThisUntil(criteria);
    }
  });
}


var okWhen = 10;
var start = 0;
function run() {

  var deferred = $q.defer();
  $timeout(function () {
    if (start !== okWhen) {
    start += 1;
    deferred.resolve("Bad");
  } else {
    deferred.resolve("Ok")
    start = 0;
  }
  }, 100);


  return deferred.promise;


}
}

我试图在这里模拟的是循环形式,我向一个http服务器发出请求,该服务器分批工作并响应"还有更多工作"直到"工作完成"。

当我尝试使用promises执行此操作时,我最终使用$ q创建了新的延期承诺,因此我等待解决的初始承诺永远不会得到解决,因为请求被重复,我通过执行相同的函数来执行如果没有完成,请再次参加。

- 编辑 我想我可以用$ scope。$ broadcast()完成它,但我想尽可能使用$ q来解决这个问题,如果可能的话不要听事件。

1 个答案:

答案 0 :(得分:0)

更新:

var app = angular.module('myApp', []);

angular.module('myApp').controller('TestCtrl', ["$timeout", "$interval", "$scope", "$q", function TestCtrl($timeout, $interval, $scope, $q) {

  activate();

  $scope.responses = [];

  function activate() {

    $scope.start = function() {

      runThisUntil("Ok").then(function() {
        $scope.responses.push("Pushed final");;
      });
    }

    $scope.clear = function() {
      $scope.responses = [];
    }

    function runThisUntil(criteria) {

      return runThis(criteria);
    }

    function runThis(criteria) {
      return run().then(function (response) {
        $scope.responses.push("Done");
      }, function () {
        $scope.responses.push("Wait");
        return runThis(criteria);
      });
    }


    var okWhen = 10;
    var start = 0;
    function run() {

      var deferred = $q.defer();
      $timeout(function () {
        if (start !== okWhen) {
        start += 1;
        deferred.reject("Bad");
      } else {
        deferred.resolve("Ok")
        start = 0;
      }
      }, 100);

      return deferred.promise;
    }

  }


}]);

http://plnkr.co/edit/MYn6otWMmxHFDd41jBpI?p=preview