AngularJS Promises - 模拟http承诺

Question

当我知道请求在服务器端失败时,我想知道如何模拟promise $ http.这是我的代码:

if ( !ng.isString(email) ) {
    var promise = $q.defer().promise;
    $q.reject();

    return promise;
}

return $http( {
         method : "PUT",
         url : "//localhost/update" ,
         data : { data: email } 
})

// Success handler
.success(response){ return response})

// Error handler
.error(errorMsg){ return errorMsg});

Answer 1

您可以使用resolve和reject来控制数据流:

假设您有这样的服务:

var app = angular.module("mymodule.services", []);

app.factory("HttpRequest", ['$q', '$http', function(q, http) {
  var deferredData = q.defer();

  http.get('http://your-server.local/data.json').success(function(data) {
    //success, resolve your promise here
    deferredData.resolve(data);
  }).error(function(err) {
    //error, use reject here
    deferredData.reject(err);
  });

  return {
    get: function() {
      return deferredData.promise;
    }
  };
}]);

然后可以使用该服务:

var app = angular.module("mymodule.controllers", ['mymodule.services']);

app.controller("MyCtrl", ['HttpRequest', '$scope', function(res, scope) {
  //the "then"-method of promises takes two functions as arguments, a success and an erro callback
  res.get().then(function(data) {
    //first one is the success callback
    scope.data = data;
  },
  function(err) {
    scope.err = err; 
  }); 
}]);

您可以在第二个回调中处理错误.

Answer 2

好的,我可以弄清楚如何模拟$ http对象返回的相同承诺.感谢大家的回答.我可以把它们都考虑进去.这是我的解决方案:

if ( !ng.isString(email) ) {

    // We need to create a promise like the one returned by the 
    // $http object (with the success and error methods)
    // to stay consistent.
    var promise = $q.reject("error with email");

    // Defining success and error method for callbacks. 
    // but it should never be called since the promise 
    // is already rejected.
    promise.success = function(fn){
       promise.then(function(response){
          fn(response)
       }, null);
          return promise
    };

    promise.error = function(fn){
       promise.then(null, function(response){
          fn(response)
       });
       return promise;
    };

    return promise;
}

return $http( {
         method : "PUT",
         url : "//localhost/update" ,
         data : { data: email } 
})

// Success handler
.success(response){ return response})

// Error handler
.error(errorMsg){ return errorMsg});