How can I send request again in response interceptor?

Question

I've made an interceptor in my application that detects session loss (server sends an HTTP 419). In this case, I need to request a new session from the server, and then I would like to send the original request again automatically.
Maybe I could save the request in a request interceptor, and then send it again, but there might be a simpler solution.

Note that I have to use a specific webservice to create the session.

angular.module('myapp', [ 'ngResource' ]).factory(     'MyInterceptor',      function ($q, $rootScope) {         return function (promise) {             return promise.then(function (response) {                 // do something on success                 return response;             }, function (response) {                 if(response.status == 419){                     // session lost                     // create new session server-side                     // Session.query();                     // then send current request again                     // ???                 }                 return $q.reject(response);             });         };     }).config(function ($httpProvider) {         $httpProvider.responseInterceptors.push('MyInterceptor');     }); 

Answer 1

Here is my solution using promises for those interested. Basically you need to request a new session, and wait for the response before sending a new request corresponding to the original request (using response.config). By returning the promise $http(response.config) you ensure that the response will be treated as if it was the original request.
(syntax may not be the best as I'm new to promises)

angular.module('myapp', [ 'ngResource' ]).factory(     'MyInterceptor',      function ($q, $rootScope) {         return function (promise) {             return promise.then(function (response) {                 // do something on success                 return response;             }, function (response) {                 if(response.status == 419){                     // session lost                     var Session = $injector.get('Session');                     var $http = $injector.get('$http');                     // first create new session server-side                     var defer = $q.defer();                     var promiseSession = defer.promise;                      Session.query({},function(){                         defer.resolve();                     }, function(){                        // error                        defer.reject();                     });                            // and chain request                     var promiseUpdate = promiseSession.then(function(){                         return $http(response.config);                     });                     return promiseUpdate;                 }                 return $q.reject(response);             });         };     }).config(function ($httpProvider) {         $httpProvider.responseInterceptors.push('MyInterceptor');     }); 

Answer 2

The responseError method of httpInterceptor have to be like this:

responseError: function (response) {   // omit the retry if the request is made to a template or other url   if (response.config.apiCal === true) {     if (response.status === 419) {       var deferred = $q.defer();       // do something async: try to login.. rescue a token.. etc.       asyncFuncionToRecoverFrom419(funcion(){         // on success retry the http request         retryHttpRequest(response.config, deferred);       });       return deferred.promise;     } else {       // a template file...       return response;     }   } } 

And the magic happens here:

function retryHttpRequest(config, deferred){   function successCallback(response){     deferred.resolve(response);   }   function errorCallback(response){     deferred.reject(response);   }   var $http = $injector.get('$http');   $http(config).then(successCallback, errorCallback); }