AngularJS using an interceptor to handle $http 404s - promise not defined error

Question

I have an Angular app, for which I want to handle 404s form an API end point. The key components are like so:

// app.js

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

myApp.config( function ($httpProvider, $interpolateProvider, $routeProvider) {
  $httpProvider.interceptors.push('httpRequestInterceptor');

  $routeProvider
    ...
    .when('/project/:projectId', {
        templateUrl : 'partials/project_detail.tmpl.html',
        controller: 'ProjectDetailCtrl',
        resolve: {
            project: function ($route, ConcernService) {
                return ConcernService.get('projects/', $route.current.params.projectId);
            },
        }
    });
});


// interceptors.js

myApp.factory('httpRequestInterceptor', function ($q, $location) {
  return {
    response: function(response){
      return promise.then(
        function success(response) {
          return response;
        },
        function error(response) {
          if(response.status === 404){
            $location.path('/404');
            return $q.reject(response);
          }
          else{
            return $q.reject(response); 
          }
        }
      );
    }
  };
});


// services.js

myApp.factory('ConcernService', function ($http, $q) {

var ConcernService = {
    ...
    get: function (items_url, objId) {
        var defer = $q.defer();
        $http({method: 'GET', 
            url: api_url + items_url + objId}).
            success(function (data, status, headers, config) {
                defer.resolve(data);
            }).error(function (data, status, headers, config) {
                // when API not found, status == 404 
                console.log('ConcernService.get status',status);
                defer.reject(status);
            });
        console.log('ConcernService.get promise',defer.promise);
        return defer.promise;
    },
}
});

The issue is I am getting an error of ReferenceError: promise is not defined at response. Is this because the ConcernService defers the promise? How should I deal with this?

Answer 1

So, my solution which works, using the new interceptor syntax is as follows:

// interceptors.js

.factory('httpRequestInterceptor', function ($q, $location) {
    return {
        'responseError': function(rejection) {
            // do something on error
            if(rejection.status === 404){
                $location.path('/404/');                    
            }
            return $q.reject(rejection);
         }
     };
});


// app.js

myApp.config( function ($httpProvider, $interpolateProvider, $routeProvider) {
    $httpProvider.interceptors.push('httpRequestInterceptor');

    $routeProvider
    ...
    .when('/404/:projectId', {
        templateUrl : 'partials/404.tmpl.html',
        controller: '404Ctrl',
        resolve: {
            project: function ($route) {
                // return a dummy project, with only id populated
                return {id: $route.current.params.projectId};
            }
        }
    });
});


// 404.tmpl.html

...

<h1>Oh No! 404.</h1> 
<p>Project with ID {{ project.id }} does not exist.</p>

This is a simplified version, but demonstrates how I used the interceptor pattern to solve my issue.

Comments are welcome.

Answer 2

I think the structure of you interceptor might be off. I posted an answer with a sample interceptor here (Handle HTTP 302 response from proxy in angularjs) that you might find useful. It works for me on a daily basis.