在服务中处理$http响应

我最近发布了一篇关于我在SO面临的问题的详细描述。由于我无法发送一个实际的$http请求，所以我使用timeout来模拟异步行为。在@Gloopy的帮助下，从我的模型到视图的数据绑定工作正常

现在，当我使用$http而不是$timeout(在本地测试)时，我可以看到异步请求是成功的，数据在我的服务中被json响应填充。但是，我的观点并没有更新。

在这里更新Plunkr

当前回答

我真的不喜欢这样一个事实，因为“承诺”的做事方式，使用$http的服务的消费者必须“知道”如何解包响应。

我只是想调用一些东西并得到数据，类似于旧的$scope。items = Data.getData();方法，现在已弃用。

我尝试了一段时间，没有想出一个完美的解决方案，但这是我最好的办法(Plunker)。它可能对某人有用。

app.factory('myService', function($http) {
  var _data;  // cache data rather than promise
  var myService = {};

  myService.getData = function(obj) { 
    if(!_data) {
      $http.get('test.json').then(function(result){
        _data = result.data;
        console.log(_data);  // prove that it executes once
        angular.extend(obj, _data);
      }); 
    } else {  
      angular.extend(obj, _data);
    }
  };

  return myService;
});

然后控制器:

app.controller('MainCtrl', function( myService,$scope) {
  $scope.clearData = function() {
    $scope.data = Object.create(null);
  };
  $scope.getData = function() {
    $scope.clearData();  // also important: need to prepare input to getData as an object
    myService.getData($scope.data); // **important bit** pass in object you want to augment
  };
});

我已经发现了一些缺陷

You have to pass in the object which you want the data added to, which isn't an intuitive or common pattern in Angular getData can only accept the obj parameter in the form of an object (although it could also accept an array), which won't be a problem for many applications, but it's a sore limitation You have to prepare the input object $scope.data with = {} to make it an object (essentially what $scope.clearData() does above), or = [] for an array, or it won't work (we're already having to assume something about what data is coming). I tried to do this preparation step IN getData, but no luck.

尽管如此，它提供了一种模式，可以删除控制器的“promise unwrap”样板文件，当您想在多个地方使用从$http获得的某些数据，同时保持其DRY时，这种模式可能很有用。

2014-09-24 17:43:16

其他回答

Tosh shimayama有一个解决方案，但你可以简化很多，如果你使用$http返回承诺，承诺可以返回一个值:

app.factory('myService', function($http, $q) {
  myService.async = function() {
    return $http.get('test.json')
    .then(function (response) {
      var data = reponse.data;
      console.log(data);
      return data;
    });
  };

  return myService;
});

app.controller('MainCtrl', function( myService,$scope) {
  $scope.asyncData = myService.async();
  $scope.$watch('asyncData', function(asyncData) {
    if(angular.isDefined(asyncData)) {
      // Do something with the returned data, angular handle promises fine, you don't have to reassign the value to the scope if you just want to use it with angular directives
    }
  });

});

coffeescript中的一个小演示:http://plunker.no.de/edit/ksnErx?live=preview

你的活塞更新了我的方法:http://plnkr.co/edit/mwSZGK?p=preview

2012-09-20 08:43:54

这里有一个Plunk，可以做你想要的:http://plnkr.co/edit/TTlbSv?p=preview

其思想是直接使用承诺及其“then”函数来操作和访问异步返回的响应。

app.factory('myService', function($http) {
  var myService = {
    async: function() {
      // $http returns a promise, which has a then function, which also returns a promise
      var promise = $http.get('test.json').then(function (response) {
        // The then function here is an opportunity to modify the response
        console.log(response);
        // The return value gets picked up by the then in the controller.
        return response.data;
      });
      // Return the promise to the controller
      return promise;
    }
  };
  return myService;
});

app.controller('MainCtrl', function( myService,$scope) {
  // Call the async method and then do stuff with what is returned inside our own then function
  myService.async().then(function(d) {
    $scope.data = d;
  });
});

这里有一个稍微复杂一点的版本，它缓存了请求，所以您只在第一次发出请求(http://plnkr.co/edit/2yH1F4IMZlMS8QsV9rHv?p=preview):

app.factory('myService', function($http) {
  var promise;
  var myService = {
    async: function() {
      if ( !promise ) {
        // $http returns a promise, which has a then function, which also returns a promise
        promise = $http.get('test.json').then(function (response) {
          // The then function here is an opportunity to modify the response
          console.log(response);
          // The return value gets picked up by the then in the controller.
          return response.data;
        });
      }
      // Return the promise to the controller
      return promise;
    }
  };
  return myService;
});

app.controller('MainCtrl', function( myService,$scope) {
  $scope.clearData = function() {
    $scope.data = {};
  };
  $scope.getData = function() {
    // Call the async method and then do stuff with what is returned inside our own then function
    myService.async().then(function(d) {
      $scope.data = d;
    });
  };
});

2012-09-20 13:19:10

请尝试下面的代码

你可以分离控制器(PageCtrl)和服务(dataService)

'use strict'; (function () { angular.module('myApp') .controller('pageContl', ['$scope', 'dataService', PageContl]) .service('dataService', ['$q', '$http', DataService]); function DataService($q, $http){ this.$q = $q; this.$http = $http; //... blob blob } DataService.prototype = { getSearchData: function () { var deferred = this.$q.defer(); //initiating promise this.$http({ method: 'POST',//GET url: 'test.json', headers: { 'Content-Type': 'application/json' } }).then(function(result) { deferred.resolve(result.data); },function (error) { deferred.reject(error); }); return deferred.promise; }, getABCDATA: function () { } }; function PageContl($scope, dataService) { this.$scope = $scope; this.dataService = dataService; //injecting service Dependency in ctrl this.pageData = {}; //or []; } PageContl.prototype = { searchData: function () { var self = this; //we can't access 'this' of parent fn from callback or inner function, that's why assigning in temp variable this.dataService.getSearchData().then(function (data) { self.searchData = data; }); } } }());

2016-11-23 01:37:41

简单点。这很简单

在您服务期间退货承诺(在您服务期间无需使用) 在你的控制器中使用then

演示。http://plnkr.co/edit/cbdG5p?p=preview

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

app.factory('myService', function($http) {
  return {
    async: function() {
      return $http.get('test.json');  //1. this returns promise
    }
  };
});

app.controller('MainCtrl', function( myService,$scope) {
  myService.async().then(function(d) { //2. so you can use .then()
    $scope.data = d;
  });
});

2013-12-20 21:34:25