如何从基于回调的 API 创建 AngularJS 承诺 [英] How to create a AngularJS promise from a callback-based API

问题描述

wifiservice.js:

wifiservice.js:

angular.module('app.WifiServices', [])
    .factory('WifiService', function(){
        var unique_array = angular.fromJson('[]');

        function win_wifi(e){
        alert("Success");
        }

        function fail_wifi(e){
        alert("Error");
        }

        function connectWifi(wifi_ssid){
          WifiWizard.connectNetwork(wifi_ssid, win_wifi, fail_wifi);
        }

        function listHandler(a){

      var network_array = [];
      for(var i=0; i<a.length; i++){
        network_array.push("SSID: " + a[i].SSID + " Signal: " + a[i].level);
      }

      unique_array = network_array.filter(function(elem, pos) {
        return network_array.indexOf(elem) == pos;
      });

      // alert("Wifi List Ready!");
    }

    function getScanResult(){
      WifiWizard.getScanResults(listHandler, failNetwork);
    }

    function successNetwork(e){
      window.setTimeout(function(){
        getScanResult();
      }, 3000);
    }

    function failNetwork(e){
      alert("Network Failure: " + e);
    }

    window.setTimeout(function(){
      WifiWizard.startScan(successNetwork, failNetwork);
    }, 1000);

        return {
          list: function(){
            return unique_array;
          },

          connectionToWifi: function(name){
            connectWifi(name);
          }
        };
    });

我的整个控制器:

app.controller('WifiController', ['$scope', 'WifiService', function($scope, WifiService) {

 $scope.wifiList = [];

 window.setTimeout(function() {
  $scope.wifiList = WifiService.list();
  // alert($scope.wifiList);
  $scope.$apply();
 }, 5000);

 $scope.getList = function() {
  $scope.wifiList = WifiService.list();
  return $scope.wifiList;
 }

 $scope.connectWifi = function(name) {
  WifiService.connectionToWifi(name);
 }

 $scope.checkin = function() {
  $scope.getList()
  .then(function(result) {
     console.log(result);
 });
}

}]);

我想要做的是调用 $scope.getList()，它返回周围 wifi SSID 的列表，然后在 $scope.checkin() 中我想处理这些数据.

What I am trying to do is, to call the $scope.getList(), which returns a list of the surrounding wifi SSIDs, then within $scope.checkin() I would like to process those data.

由于扫描需要一些时间，我必须等待 getList 函数完成，这就是我尝试使用 .then 的原因，但它给了我标题上的错误信息.有什么想法吗?

Since scanning needs some time I have to wait the getList function to finish, thats Why I am trying to use .then, but it gives me the error says on the title. Any ideas?

推荐答案

好吧，我想出了一些不同的东西:

Well, I came up with something different:

var unique_array = [];
  $scope.wifiList = [];
  $ionicLoading.show({
    template: "Scanning surrounding AP's..."
  });

 window.setTimeout(function() {
  $scope.wifiList = WifiService.list();
  // alert($scope.wifiList);
  while ($scope.wifiList == []) {
    console.log('Scanning...');
  }
  $scope.$apply();
  $ionicLoading.hide();
 }, 5000);

我意识到，一旦我加载了视图，扫描就会开始.因此，我添加了一个 IonicLoader 来强制用户等待，并且在扫描完成之前无法按下任何按钮.因此，任何功能都不应相互等待.在代码方面不太正确，但它可以满足我的需求.

What I realize is that the scanning starts once I load the view. So, I added an IonicLoader to force the user to wait, and not be able to press any buttons till the scan is finished. So no function shall wait one another. Not quite code-wise correct, but it does what I need.

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