Short : Is there any way to modify the backed NSURLRequest (headers, body, or other) of the Request object after it has been created ?
Long : I have a custom Manager with startRequestsImmediately set to false. If my access token is currently being refreshed, all requests are waiting for refresh to finish, then they are resume.
Of course, I need to modify theirs HTTP headers to update access token before resuming them.
I can't just track directly NSURLRequests then recreating Requests object because I need to keep all completion closure previously set for those requests.
Is anyone find a way to do that ?
Thanks for your help.
You can use a RequestAdapter. Example:
class MyAdapter: RequestAdapter {
func adapt(_ urlRequest: URLRequest) throws -> URLRequest {
var urlRequest = urlRequest
urlRequest.setValue("Bar", forHTTPHeaderField: "X-Foo")
return urlRequest
}
}
// Then...
let manager = SessionManager()
manager.adapter = MyAdapter()
manager.request("https://httpbin.org/get")
Related
The server returning a json file that is:
{"ctrl":{"code":400,"text":"Not valid Access token","ts":"2020-03-05T11:54:01.547Z"}}
Code:
public func startDownload(url: URL, pathURL: URL) {
let accessToken: String! = "Bearer \(Constants.access_token)"
self.dirURL = pathURL
var request = URLRequest(url: url)
guard let token = accessToken else { return }
request.addValue(token, forHTTPHeaderField: "Authorization")
downloadTask = backgroundSession.downloadTask(with: request)
downloadTask.resume()
}
FYI: access token is valid, it is working with Postman.
You're going to have a problem because, unfortunatelly, there's no good solution to this issue. Authorization is one of the Reserved HTTP Headers and setting it either in URLRequest header, or in URLSessionConfiguration.httpAdditionalHeaders may simply not work:
If you set a value for one of these reserved headers, the system may ignore the value you set, or overwrite it with its own value, or simply not send it.
One might expect you could provide this token in URLSessionTaskDelegate method urlSession(_:task:didReceive:completionHandler:) which handles authentication challenges, but in there you need to provide a URLCredential object, and sadly it doesn't have a constructor that takes a Bearer token, so that's a no-go.
So basically, short of writing your own URLProtocol implementation, your best bet would be to send the token in some additional, custom, header field and have the server grab it from there (if you have control over server code). Source
The backend APIs I'm working with require a token to be sent with every request against the HTTP header key Authorization in this format - Token xxxxxxxxxx.
Right now, I'm doing the following.
var getRequest = URLRequest(url: url)
getRequest.addValue("Token xxxxxxxx", forHTTPHeaderField: "Authorization")
This works sometimes and some other times, the header field Authorization is stripped when the request is sent out. I checked this using Charles proxy.
Apple's documentation states the following.
An NSURLSession object is designed to handle various aspects of the
HTTP protocol for you. As a result, you should not modify the
following headers: Authorization, Connection, Host, WWW-Authenticate
As a solution to this, many suggest using the didReceiveAuthenticationChallenge delegate method for URLSession.
Here, you need to pass a URLSession.AuthChallengeDisposition instance to tell how you want to respond to the challenge and a URLCredential instance to pass the credentials to respond to the authenticate challenge.
I do not know how to and if I can create a URLCredential instance that will add Token xxxxxxxx for the header field Authorization.
Can somebody more knowledgeable please help me how to go about solving this?
PS - All code mentioned in this question is in Swift 3.
This question asks something similar to what I have. But, the answers given there don't work for me. And, some of the questions asked under the questions regarding Apple not allowing headers for Authorization to be added have gone unanswered.
Edit:
Posting relevant code.
var getRequest = URLRequest(url: url)
getRequest.httpMethod = "GET"
getRequest.addValue("application/json", forHTTPHeaderField: "Content-Type")
getRequest.addValue("application/json", forHTTPHeaderField: "Accept")
let token = DataProvider.sharedInstance.token
getRequest.addValue("Token \(token)", forHTTPHeaderField: "Authorization")
let getTask = URLSession.shared.dataTask(with: getRequest) { (data, response, error) in
if let data = data {
print("--------GET REQUEST RESPONSE START--------")
print("CODE: \((response as? HTTPURLResponse)?.statusCode ?? 0)")
print("Response Data:")
print(String(data: data, encoding: .utf8) ?? "")
print("--------GET REQUEST RESPONSE END--------")
}
}
getTask.resume()
Here, I can confirm that the header field for 'Authorization' is getting added to the request's header dictionary.
But, when I check what request hits the server, the header field for 'Authorization' is missing. Any thoughts?
I ran into this exact same issue and discovered that my lack of a trailing slash, /, was the problem.
The server was sending back a 301 Redirect response. URLSession automatically follows the redirect, but will also drop the Authorization header. This is likely due to Authorization's "special status". According to URLSessionConfiguration's documentation:
An URLSession object is designed to handle various aspects of the HTTP protocol for you. As a result, you should not modify the following headers:
Authorization
Connection
Host
WWW-Authenticate
If the Authorization header is required, implement urlSession(_:task:willPerformHTTPRedirection:newRequest:completionHandler:) from URLSessionTaskDelegate. That method is passed the new request on redirect, allowing you to add back the header.
e.g.
class APIClient: URLSessionTaskDelegate {
let session: URLSession!
initializeSession() {
// Create a new session with APIClient as the delegate
session = URLSession(configuration: URLSessionConfiguration.default,
delegate: self,
delegateQueue: nil)
}
// Perform the request
func fetchRecords(handler: () => void) {
var request = URLRequest(url: URL(string: "http://127.0.0.1:8000/api/employee/records")!)
request.setValue(retrieveToken(), forHTTPHeaderField: "Authorization")
session.dataTask(with: request, completionHandler: handler).resume()
}
// Implement URLSessionTaskDelegate's HTTP Redirection method
func urlSession(_ session: URLSession, task: URLSessionTask, willPerformHTTPRedirection response: HTTPURLResponse, newRequest request: URLRequest, completionHandler: #escaping (URLRequest?) -> Void) {
// Create a mutable copy of the new request, add the header, call completionHandler
var newRequest = request
newRequest.addValue(retrieveToken(), forHTTPHeaderField: "Authorization")
completionHandler(newRequest)
}
}
IMPORTANT NOTE!
It's a bad idea to blindly trust a redirect. You should ensure that the URL you're being redirected to is the same domain as the original request. I've left that out of my code example for brevity.
I am trying in the Request Adapter of Alamofire to add a GET parameter. However in the request adapter I am only able to add HTTPHeader fields.
Currently my request adapter looks like:
// MARK: - RequestAdapter
func adapt(_ urlRequest: URLRequest) throws -> URLRequest {
if let url = urlRequest.url, url.lastPathComponent.hasPrefix(baseURLString) {
var urlRequest = urlRequest
// Want to inject param here
// e.g. urlRequest.addParam(param: "session", value: sessionToken")
return urlRequest
}
return urlRequest
}
I have a Router configured for the Paths but since I want my AuthHandler to be responsible to all Authentication related stuff I want to inject my sessionToken. This makes sure, together with RequestRetrier that any HTTP 401 related error is dealt with.
What is the best way to change the urlRequest?
Can you try
let params: Parameters = ["session": sessionToken]
return URLEncoding.default.encode(urlRequest, with: params)
(or)
return URLEncoding.queryString.encode(urlRequest, with: params)
Thanks
Sriram
I'm using the following code to test a behavior in NSURLCache. I initialize an API instance in AppDelegate. I configure the manager according to Alamofire's documentation, I configure the shared cache, and I assign dataTaskWillCacheResponse to make sure that the response will indeed be cached.
Then I call makeRequest which checks if a cached response exists (which it shouldn't on the first launch) and then I use my manager to make a request using the same URL so that the request is equivalent throughout the test.
My breakpoint at dataTaskWillCacheResponse is hit, I continue, the responseJSON block is executed and is Successful so I performTests using the request.
First, I check if the response is cached. It is: good!
Second, (and this is the problem) I remove the cached response for that request and then check if it exists. It does: bad!
Third, I check if removing all cached responses will remove that response. It does: good! But it's odd that that worked and the previous attempt at just removing the single response didn't...
Here's the code:
import Alamofire
class API: Manager.SessionDelegate {
var manager: Manager!
override init() {
super.init()
manager = Manager(session: urlSession(), delegate: self)
configureCache(memoryCapacityMB: 5, diskCapacityMB: 25)
manager.delegate.dataTaskWillCacheResponse = { urlSession, dataTask, cachedResponse in
// Placing a breakpoint here confirms that the response is going to be cached
return cachedResponse
}
}
private func urlSession() -> NSURLSession {
let configuration = NSURLSessionConfiguration.defaultSessionConfiguration()
return NSURLSession(configuration: configuration, delegate: self, delegateQueue: nil)
}
private func configureCache(memoryCapacityMB memory: Int, diskCapacityMB disk: Int) {
let memoryCapacity = memory * 1024 * 1024
let diskCapacity = disk * 1024 * 1024
let sharedCache = NSURLCache(memoryCapacity: memoryCapacity, diskCapacity: diskCapacity, diskPath: nil)
NSURLCache.setSharedURLCache(sharedCache)
}
// MARK: Request
func makeRequest() {
// The response should be nil on the first launch since nothing has been cached
let request = NSURLRequest(URL: NSURL(string: "http://jsonplaceholder.typicode.com/posts")!)
let response = NSURLCache.sharedURLCache().cachedResponseForRequest(request)
print(response)
manager.request(.GET, request.URLString).responseJSON { response in
switch response.result {
case .Success:
self.performTests(with: response.request!)
case .Failure:
break
}
}
}
func performTests(with request: NSURLRequest) {
// Should exist
var response = NSURLCache.sharedURLCache().cachedResponseForRequest(request)
print(response)
// And it does: good!
// Remove the cached resopnse and check if it exists
NSURLCache.sharedURLCache().removeCachedResponseForRequest(request)
response = NSURLCache.sharedURLCache().cachedResponseForRequest(request)
print(response)
// And it does: bad!
// Try removing all cached responses and check if it exists
NSURLCache.sharedURLCache().removeAllCachedResponses()
response = NSURLCache.sharedURLCache().cachedResponseForRequest(request)
print(response)
// And it doesn't: good! But odd...
}
}
So how does one remove the cached response of a single request then? And is this unintended behavior? Or is NSURLCache behaving correctly and I'm just missing something? Thanks ahead of time for taking a look!
My recollection is that most URL cache changes are not synchronous. They only actually happen after you return to the run loop and allow various asynchronous callbacks to occur.
Try running the rest of the code asynchronously after a delay of 3-5 seconds and see if the request has been removed.
If that doesn't fix the problem, file a bug.
I have built an app that includes a WKWebView, and the website that the web view loads supports multiple languages. How can I change the Accept-Language header in a WKWebView, or other HTTP headers for that matter?
I've got it working in a way, but only get requests will have the custom header. As jbelkins answered in the linked so from Gabriel Cartiers comment to your question, you will have to manipulate the request and load it anew.
I've got it working for GET-Requests like this:
(it's in xamarin 0> c#, but i think you will get the idea)
i've created a private field
private bool _headerIsSet
which i check every time a request is made in the deligate method:
[Foundation.Export("webView:decidePolicyForNavigationAction:decisionHandler:")]
public void DecidePolicy(WKWebView webView, WKNavigationAction navigationAction, Action<WKNavigationActionPolicy> decisionHandler)
{
var request = navigationAction.Request;
// check if the header is set and if not, create a muteable copy of the original request
if (!_headerIsSet && request is NSMuteableUrlRequest muteableRequest);
{
// define your custom header name and value
var keys = new object[] {headerKeyString};
var values = new object[] {headerValueString};
var headerDict = NSDictionary.FromObjectsAndKeys(values, keys);
// set the headers of the new request to the created dict
muteableRequest.Headers = headerDict;
_headerIsSet = true;
// attempt to load the newly created request
webView.LoadRequest(muteableRequest);
// abort the old one
decisionHandler(WKNavigationActionPolicy.Cancel);
// exit this whole method
return;
}
else
{
_headerIsSet = false;
decisionHandler(WKNavigationActionPolicy.Allow);
}
}
As i said, this only works for GET-Requests. Somehow, POST-Requests don't contain the body data of the original request (request.Body and request.BodyStream are null), so the muteableRequest (which is a muteable copy of the original request) won't contain the body data of the original request.
I hope this will help you or others that approach the same problem.
Edit: For your needs, set "Accept-Language" as the key
Simply can set needed language ISO 639-1 code in URL request like below, so that we can get user preferred or locale language response from server side.
Swift 4 & above
var request = URLRequest(url: URL(string: "YourUrlStr"))
request.setValue("en", forHTTPHeaderField: "Accept-Language")
wkWebView.load(request)
Objective-C
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:YourUrlStr]];
[request setValue:#"en" forHTTPHeaderField:#"Accept-Language"];
[wkWebView loadRequest:urlRequest];
WKWebView supports localization out of the box. You will not be required set the 'Accept-Language' header field.
For some reason if you are required to, this is how it can be done.
Create a 'URLRequest' an instance of URL initialized with the desired website
var request = URLRequest(url: url)
Maintain a mapping of locales required and set the 'Accept-Language' header field accordingly
request.setValue("de-de", forHTTPHeaderField: "Accept-Language")
Load the 'URLRequest' using an instance of 'WKWebView'
webview.load(request)
Similarly any header field can be changed