Prevent redirect response with Alamofire in Swift - swift

Question

I'm looking for example code how to prevent redirect response (status code 3xx) when request web api. I'm using Swift with Alamofire 1.2.
I have tried:
delegate.taskWillPerformHTTPRedirection = { (session: NSURLSession!, task: NSURLSessionTask!, response: NSHTTPURLResponse!, request: NSURLRequest!) in
return nil
}
but not work
I've also tried: https://github.com/Alamofire/Alamofire/pull/350/files and have changed my own code to:
var acc = self.txtAccount.text
var pwd = self.txtPassword.text
var url : String = "http://10.1.0.2:8081/wordpress/wp-json/users/me"
let delegate = Alamofire.Manager.sharedInstance.delegate
delegate.taskWillPerformHTTPRedirection = { (session: NSURLSession!, task: NSURLSessionTask!, response: NSHTTPURLResponse!, request: NSURLRequest!) in
var request = NSMutableURLRequest(URL: NSURL(string: url)!)
request.HTTPMethod = "GET"
var credential = "\(acc):\(pwd)"
var authData = credential.dataUsingEncoding(NSUTF8StringEncoding)
var encodedAuthData = authData?.base64EncodedStringWithOptions(nil)
var authValue = "Basic \(encodedAuthData!)"
request.setValue(authValue, forHTTPHeaderField: "Authorization")
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.setValue("application/json", forHTTPHeaderField: "Accept")
return request
}
//I've implemented URLRequestConvertible 'Router'. it also have call the same above url
Alamofire.request(Router.Authorize(acc, pwd))
.response({(request, response, data, error) in
println(request)
})
But it's not worked and seem like turned to infinite loop. I tested on Charles.

Answer 1

Alternative (code snippet) solution using AlamoFire 2.4 (Xcode7). In my case, I always expect a redirect. (I am unpacking a shortened link.) If the completion in the request.response call runs, that is an error to me.
func printRedirectUrl() {
// taskWillPerformHTTPRedirectionWithCompletion: ((NSURLSession, NSURLSessionTask, NSHTTPURLResponse, NSURLRequest, NSURLRequest? -> Void) -> Void)?
Alamofire.Manager.sharedInstance.delegate.taskWillPerformHTTPRedirectionWithCompletion = { session, task, response, request, completion in
// request.URL has the redirected URL inside of it, no need to parse the body
print("REDIRECT Request: \(request)")
if let url = request.URL {
print("Extracted URL: \(url)")
}
Alamofire.Manager.sharedInstance.delegate.taskWillPerformHTTPRedirection = nil // Restore redirect abilities
return
}
// We expect a redirect, so the completion of this call should never execute
let url = NSURL(string: "https://google.com")
let request = Alamofire.request(.GET, url!)
request.response { request, response, data, error in
print("Logic Error, response should NOT have been called for request: \(request)")
Alamofire.Manager.sharedInstance.delegate.taskWillPerformHTTPRedirection = nil // Restore redirect abilities - just in case
}
}
REDIRECT Request: { URL: https://www.google.com/ }
Extracted URL: https://www.google.com/

Answer 2

In Swift 4,
let delegate = Alamofire.SessionManager.default.delegate
delegate.taskWillPerformHTTPRedirection = { (session, task, response, request) -> URLRequest? in
// print("REDIRECT Request: \(request)")
return nil
}

Answer 3

Hello its actually pretty simple
Alamofire has a redirector that will
Example
let request = AF.request("https://google.com",method: .post,parameters: parameters)
.cURLDescription { description in
debugPrint(description)
}
let redirector = Redirector(behavior: .doNotFollow)
request.redirect(using: redirector)
with that it wont redirect
its also in the docs in the advanced usage section

Answer 4

It looks like returning nil can possibly cause a deadlock. Instead, try to create a new NSURLRequest with the same original URL. See #jhersh's notes in a previous Alamofire PR along with the comments and implementation in his tests.
How to Stop a Redirect
func disallowRedirect() {
let URL = "http://google.com/"
let delegate = Alamofire.Manager.sharedInstance.delegate
delegate.taskWillPerformHTTPRedirection = { session, task, response, request in
return NSURLRequest(URL: NSURL(string: URL)!)
}
let request = Alamofire.request(.GET, URL)
request.response { request, response, data, error in
println("Request: \(request)")
println("Response: \(response)")
println("Data: \(NSString(data: data as! NSData, encoding: NSUTF8StringEncoding))")
println("Error: \(error)")
}
}
disallowRedirect()
The fact that you cannot pass nil into the NSURLSessionTaskDelegate method's completionHandler looks like a bug. I'm going to file a radar for this and I'll post a link to the bug report once I'm finished.

Answer 5

I don't know if your version of Alamofire has a support for public delegate. Last time I checked delegate was private. I am using the changes made by #jhersh. You can check his additions and how to use delegate by followin github pr. https://github.com/Alamofire/Alamofire/issues/314