AngularJS 成功后回调即使发生错误也会触发

Question

为什么当响应为 500 时会在这里触发成功回调？

$scope.submit = function() {
    var user = $scope.user;
    // provide username and password to obtain a token which will be used for api calls
    $http.post('/authenticate', user).
        success(function(data, status, headers, config) {
            $window.sessionStorage.token = data.token;
            $location.path('/');
        }).
        error(function(data, status, headers, config) {
            $scope.errors = data.errors;
            $scope.message = 'Invalid JSON format, see guidelines for correct format';
            $scope.uploadError = true;
            console.log('ERROR TRUE');
        });
};

拦截器:

angular.module('uploadApp')
       .factory('authInterceptor',

function ($rootScope, $q, $window, $location) {
  return {
    request: function (config) {
      config.headers = config.headers || {};
      if ($window.sessionStorage.token) {
        config.headers.Authorization = 'Bearer ' + $window.sessionStorage.token;
      }
      return config;
    },
    response: function (response) {
      return response || $q.when(response);
    },
    responseError: function(response) {
      if (response.status === 401) {
         $location.path('/login');

      }
      return response || $q.when(response);
    }
  };
});

Answer 1

Angular $q promise 的工作方式是，需要不处理错误才能继续沿着错误路径前进 - 否则它假设您已经纠正了问题或处理了错误。因此，最简单的方法是抛出来自错误路径的响应，直到到达您真正想要处理它的位置。

angular.module('uploadApp')
   .factory('authInterceptor',

function ($rootScope, $q, $window, $location) {
  return {
    request: function (config) {
      config.headers = config.headers || {};
      if ($window.sessionStorage.token) {
        config.headers.Authorization = 'Bearer ' +
            $window.sessionStorage.token;
      }
      return config;
   },
   response: function (response) {
     return response || $q.when(response);
   },
   responseError: function(response) {
     if (response.status === 401) {
       $location.path('/login');
     }
     // instead of returning, you should throw, 
     // and when you throw you don't need to wrap, as it will
     // handle it for you.
     //return response || $q.when(response);
     throw response;
   }
  };
});

$q 将确保抛出的对象被包装在 Promise 调用链中。请注意，每当您在 $q promise 中返回时，它都会假设您已经处理了任何问题，除非您抛出而不是返回。这允许您在调用链下游的解析器中出现错误，然后将其视为错误。

如果抛出不是您的风格，您可以推迟一个新的 promise 并返回它，然后拒绝它 - 但这比使用当前的调用链效率低得多。