Angular JS $httpProvider interceptor -- run with no response body? - javascript

I'm using interceptors to keep a running count of all $http requests; incrementing whenever a request starts, and decrementing whenever a response comes back. The point of doing this is to allow me to show a busy spinner when any response has not yet come back without having to write the same code over and over again.
The code doing the heavy lifting is here (I've truncated the other interceptors which aren't really relevant here):
$httpProvider.interceptors.push(['$q', '$injector', function($q, $injector)
{
return {
'request': function(config)
{
httpMonitorServiceProvider.activeHttpCalls++;
return config;
},
'response': function(data)
{
httpMonitorServiceProvider.activeHttpCalls--;
return data;
}
}
}
This code works great for the most part, but some of the REST endpoints I have just return an HTTP OK status code without a response body (for POSTed "save" calls and the like where there's no need to return anything). When there's no response body the response interceptor never seems to be hit, so the counter never goes back down. If I modify the endpoints to return {} it does work.
Is there a way to intercept the responses that have no body? I can modify the REST endpoints but I consider it less than ideal to have to return empty objects everywhere to hack around this issue.

Related

AngularJs: how to hold all the $http request if its thrown unauthorised request error refresh token and resume all the request

i have developed single page application in angularjs. i have implemented the refresh token mechanism. refresh token suppose to refresh every 30 minutes. I am trying to handle refresh token in responseError of interceptor. I m trying to hold request if it returns 401 unauthorised error. Is there any mechanism to hold all the request once it return 401 error then refresh token and resume all request with new token.
Is it right way to handle the refresh token, here is sample code
$provide.factory('httpTokenInterceptor', function ($q, $injector, $cookies) {
return {
// On request sending
request: function (config) {
config.headers = config.headers || {};
// get this data from $cookies
var globals = $cookies.getObject('globals') || {};
//console.log(globals);
if (globals.authData)
config.headers.Authorization = 'Bearer ' + globals.authData.access_token;
return config;
},
// On response failure
responseError: function (rejection) {
console.log('AuthTokenHttpInterceptor responseError');
console.log(rejection);
if (rejection.status === 401) {
//hold current and all pending request
var aService = $injector.get('authenticationService');
aService.getRefreshToken().then(function(response) {
//need to resume all the request here
deferred.resolve(response);
});
return deferred.promise;
}
return $q.reject(rejection);
}
};
});
In short, you don't want to hold up any of your HTTP calls like that.
Your solution will go and refresh your token after one of your HTTP calls already failed. Also, just to be clear, your code is adding Authorization header even on HTTP calls that are getting resources like HTML templates. If you don't want to do this, then you should restrict that as well.
For one solution, check out this link. It doesn't use any particular library for handling JWT tokens, but you will have to create a wrapper around this implementation to use it wherever you need to do a HTTP call.
My suggestion (and personal preference when handling JWT tokens) is using the angular-jwt library. It's really easy to set up and you can check it out here.
There more complex libraries like auth0, which can do a lot of other stuff, and can be used in conjuction with angular-jwt library. Check out this link to see how to handle token refreshing both prior to a HTTP call and on page refresh.
Hope this helps.
You can hold requests and resume them using AngularJS Interceptors.
authInterceptor.$inject = ['$q', '$rootScope'];
function authInterceptor($q, $rootScope) {
return {
request: function(config) {
var deferred = $q.defer();
$rootScope.$watch('continue', function(value) {
if(value === true)
deferred.resolve(config);
});
return deferred.promise;
}
};
}
In the above example all of the requests hold until $rootScope.continue becomes true. Otherwise they will wait forever.

How should AngularJS handle 403 error in $http.post due to outdated XSRF token?

An AngularJS version 1.4.8 app is getting an unhandled 403 error when its login form sends data to a backend REST authentication service after the user's browser has been left open for many (16 in this case) hours. Upon deeper analysis, the root cause is that the client AngularJS app has outdated cookies for XSRF-TOKEN and JSESSIONID, which causes the backend Spring Security to reject the request to the public /login1 service because Spring thinks the request is cross site request forgery.
The problem can be resolved manually if the user closes all browser windows and then re-opens a new browser window before making the request again. But this is not an acceptable user experience. I have read the AngularJS documentation at this link, and I see that I can add an errorCallback function, but how specifically should i re-write the function to handle the 403 error?
Here is the original this.logForm() method in the authorization service, which you can see does not handle 403 errors:
this.logForm = function(isValid) {
if (isValid) {
var usercredentials = {type:"resultmessage", name: this.credentials.username, encpwd: this.credentials.password };
$http.post('/login1', usercredentials)
.then(
function(response, $cookies) {
if(response.data.content=='login1success'){// do some stuff
} else {// do other stuff
}
}
);
}
};
Here is my very rough attempt at a revised version of the this.logForm() method attempting to handle a 403 error following the example in the AngularJS documentation:
this.logForm = function(isValid) {
if (isValid) {
var usercredentials = {type:"resultmessage", name: this.credentials.username, encpwd: this.credentials.password };
$http({ method: 'POST', url: '/login1', usercredentials })
.then(
function successCallback(response, $cookies) {
// this callback will be called asynchronously when the response is available
if(response.data.content=='login1success'){// do some stuff
} else {// do other stuff
}
},
function errorCallback(response, status) {// is status a valid parameter to place here to get the error code?
// called asynchronously if an error occurs or server returns response with an error status.
if(status == 403){
this.clearCookies();
// try to call this POST method again, but how? And how avoid infinite loop?
}
}
);
}
};
What specific changes need to be made to the code above to handle the 403 error due to server-perceived XSRF-TOKEN and JSESSIONID issues? And how can the post be called a second time after deleting the cookies without leading to an infinite loop in the case where deleting the cookies does not resolve the 403 error?
I am also looking into global approaches to error handling, but there is a combination of public and secure backend REST services, which would need to be handled separately, leading to complexity. This login form is the first point of user entry, and I want to handle it separately before looking at global approaches which would retain a separate handling of the login form using methods developed in reply to this OP.
You could restructure your http calls to auto retry, and use promises in your controllers (or whatever)
var httpPostRetry = function(url, usercredentials) {
var promise = new Promise(function(resolve, reject) {
var retries = 0;
var postRetry = function(url, usercredentials) {
if (retries < 3) {
$http({ method: 'POST', url: '/login1', usercredentials })
.then(function(result) {
resolve(result);
}).catch(function(result) {
retries ++;
postRetry(url, usercredentials);
});
} else {
reject(result);
}
};
}.bind(this));
return promise;
}
and then you would call
httpPostRetry(bla, bla).then(function(result) {
// one of the 3 tries must of succeeded
}).catch(function(result) {
// tried 3 times and failed each time
});
To handle specific http errors you can broadcast that specific error and handle that case in a specific controller. Or use a service to encapsulate the status and have some other part of your code handle the UI flow for that error.
$rootScope.$broadcast('unauthorized http error', { somedata: {} });
Does this help?
Have a look at the angular-http-auth module and how things are done there. I think one key element you would want to use is a http interceptor.
For purposes of global error handling, authentication, or any kind of
synchronous or asynchronous pre-processing of request or
postprocessing of responses, it is desirable to be able to intercept
requests before they are handed to the server and responses before
they are handed over to the application code that initiated these
requests. The interceptors leverage the promise APIs to fulfill this
need for both synchronous and asynchronous pre-processing.
After playing around with interceptors you can look at the angular-http-auth http buffer and the way they handle rejected requests there. If their interceptor receives a responseError, they add the config object - which basically stores all information about your request - to a buffer, and then any time they want they can manipulate elements in that buffer. You could easily adept their code to manipulate the config's xsrfHeaderName, xsrfCookieName, or parameters on your behalf when you receive a 403.
I hope that helps a little.

AngularJS include API key in a get request

I am trying to get information from a fantasy data API using AngularJS. I am using $resource to perform my get request in my controller, but I haven't been able to figure out how to correctly include the API key. Do I need to include it as a header? Thanks.
nflApp.controller('mainController', ['$scope','$resource','$routeParams', function($scope, $resource, $routeParams) {
$scope.fantasyAPI = $resource("https://api.fantasydata.net/nfl/v2/JSON/DailyFantasyPlayers/2015-DEC-28", { callback: "JSON_CALLBACK" }, { get: { method: "JSONP"}});
console.log($scope.fantasyAPI);
}]);
Below is the http request info from the site.
You should set a header with the API key, AngularJS will send them with every request in the following case:
$http.defaults.headers.common["Ocp-Apim-Subscription-Key"] = key;
When adding '.common' you are telling angular to send this in every request so you do not need to add it to every resource that hits the API.
A easy way to do that is by creating your own interceptors from $httpProvider at "config" fase.
To do that, just write something like:
mymodule.config(['$httpProvider', function($httpProvider){
$httpProvider.interceptors.push(function ($q) {
return {
'request': function (config) {
config.headers['Ocp-Apim-Subscription-Key'] = SomeUserClass.AuthToken();
return config;
},
'response': function (response) {
return response;
}
};
});
});
You need to modify request header in JSONP. Unfortunately it is not possible. As the browser is responsible for header creation and you just can't manipulate that when using JSONP method.
how to change the headers for angularjs $http.jsonp
Set Headers with jQuery.ajax and JSONP?
From that link - https://johnnywey.wordpress.com/2012/05/20/jsonp-how-does-it-work/
Why NOT To Use JSONP?
Deciding against using JSONP is directly related to how it works. First of all, the only HTTP method you can use is GET since that is the only method script tags support. This immediately eliminates the use of JSONP as an option to interact with nice RESTful APIs that use other HTTP verbs to do fun stuff like CRUD. And while we’re on the subject of GET, note that using anything other than URL parameters to communicate with the server API (e.g. sending some JSON over) is also not possible. (You could encode JSON as a URL parameter, but shame on you for even thinking that.)
If they only work with header manipulation you will need to do that call from your server side.

Angular HTTP within a HTTP Interceptor

I need to append the necessary HMAC headers to a request. This should not be very difficult however I am starting to get frustrated. What is wrong with the following code. The actual http call I am doing works; I have run this call myself and it returns the necessary data. It does not work inside the interceptor.
I merely want to get the current implementation working before I add whitelist or blacklist and other customizable data for this interceptor. This is not a question about hmac however but with promises.
The error in this interceptor is with the entire promise line starting at $http(...). When i remove this block and use it as is (minus promise execution) it works fine. As soon as i uncomment the line it gets stuck in a loop and crashes chrome. Everywhere I have read says this is how it is done, but this clearly does not work.
function requestInterceptor(config){
var $http = $injector.get('$http');
var deferred = $q.defer();
$http.get(hmacApiEndpoint, {cache: true}).then(function(data){
console.log('HMAC - Success', data)
deferred.resolve(config)
}, function(config){
console.log('HMAC - Error', config)
deferred.resolve(config)
})
return deferred.promise;
}
return {
request: requestInterceptor
};
Does this have something to do with the fact that angulars $http promise is a different implementation than that of '$q'?
It doesn't look like you are actually amending the config with the newly obtainted HMAC.
Also, you'd need to protect against your requestInterceptor intercepting the call to obtain the HMAC, thus resulting in an infinite loop.
And lastly, you don't need deferred here - just return the promise produced by $http (or $http.then()):
function requestInterceptor(config){
var $http = $injector.get('$http');
// just return, if this is a call to get HMAC
if (config.url === hmacApiEndpoint) return config;
return $http.get(hmacApiEndpoint, {cache: true})
.then(function(response){
console.log('HMAC - Success', response.data)
// not sure where the HMAC needs to go
config.headers.Authorization = response.data;
return config;
})
.catch(function(){
return $q.reject("failed to obtain HMAC");
});
}
return {
request: requestInterceptor
};

angular - $http first call is super slow

A controller has $http that calls an api backend on Flask. I have some basic authentication and crossdomain is set. The first time it enters the cpuListCtrl controller the $http calls takes cca. ~14sec. The next time i visited the controller in angular it takes just 23ms. But every time i press the browsers refresh, back to ~14sec. Direct api call from browser also takes just 23ms. So my question is my does it takes so long, did i miss something, or where specific should i look?
EDIT: updated the code to reflect recent changes:
var app = angular.module('RecycleApp', ['ngRoute', 'appControllers']);
app.config(['$httpProvider', function($httpProvider) {
$httpProvider.defaults.useXDomain = true;
delete $httpProvider.defaults.headers.common['X-Requested-With'];
}
]);
app.config(['$routeProvider', function($routeProvider){
$routeProvider
.when("/cpu", {
templateUrl:'static/js/partials/cpu.html',
controller:'cpuCtrl'
})
}]);
var appControllers = angular.module('appControllers', []);
appControllers.controller('cpuCtrl', ['$scope','$http',
function($scope,$http){
$http({
url: 'http://SOME_IP/api/v1/cpus',
method: 'POST',
data: JSON.stringify({"latitude":46.1948436, "longitude":15.2000873}),
headers: {"Content-Type":"application/json"}
})
.success(function(data,status,headers,config){
console.log(data.list);
$scope.cpus = data.list;
})
.error(function(data,status,headers,config){
console.log("something went wrong.");
})
}]);
Server side:
#app.route('/api/v1/cpus', methods=["GET"])
#cross_origin(origins='*', headers=("Content-Type"))
def get_cpu_list():
result = session.query(RecycleReUseCenter)\
.options(load_only("Id", "CpuName"))\
.all()
return list_json(result)
#app.route("/api/v1/cpus", methods=["POST"])
#cross_origin(origins='*', headers=("Content-Type"))
def get_cpu_list_with_locations():
content = request.get_json(force=True)
given_latitude = content['latitude']
given_longitude = content['longitude']
result = RecycleReUseCenter.get_all_with_distance(given_latitude, given_longitude)
return list_json(result)
Do you know for sure when does the http call starts? The angular app may be stuck somewhere else, and getting to the http call only in the last second. For example - in the config you are using a "token" where do you get it from? in many angular app this is fetched from some oauth service, in a seperete call. Your slow call won't start until http is configured. After token is there, the next calls would be faster since we got the token already.
To limit some guessing you can use a proxy tool like charles - or deflect.io chrome extension to watch all the out going http calls and figure this out
I have recently had the same problem, and found that the delay oddly enough actually seems to be on the Flask end, but only happens when using an Angular app running in Chrome. This answer from the python stackexchange forum is the best one I have seen - https://stackoverflow.com/a/25835028/1521331 - it provides a 'solution' of sorts, if not an explanation for this mystery!
I was having the same problem, and none of the above worked for me. Here's what did:
Slow Requests on Local Flask Server
Effectively, certain browsers will attempt to access IPv6 sockets before IPv4. After commenting out the offending lines in /etc/hosts and restarting apache the problem was fixed.

Categories