how to ignore cached response using Alamofire?

Question

Using Alamofire with configurations like this, leading to error -999 request cancelled

let configuration = URLSessionConfiguration.default
    configuration.timeoutIntervalForRequest = 20
    configuration.requestCachePolicy = .reloadIgnoringLocalCacheData
    var sessionManager = Alamofire.SessionManager(configuration: configuration)
    sessionManager.request(url,
                              method: methodType,
                              parameters: resource.parameters,
                              headers: resource.headers)

However when i use it like this, directly it works fine, but it caches the responses ..

Alamofire.request(url,
                          method: methodType,
                          parameters: resource.parameters,
                          headers: resource.headers)

I need to ignore the cached data, and using the first is not working .

Possible duplicate of [How to disable caching in Alamofire](https://stackoverflow.com/questions/32199494/how-to-disable-caching-in-alamofire) — Rishab, Sep 03 '19 at 10:55
I don't think caching is your real problem here. I think you should look into why your first code is returning -999 error. What happens if you remove `timeoutIntervalForRequest` and `requestCachePolicy`? — Rishab, Sep 03 '19 at 11:14

Varun Malhotra · Accepted Answer · 2019-09-03T10:59:57.517

1

Not sure why you are getting this error, but there are a number of ways to solve this error.

1.You can add timestamp to your API url so so that you would never get a cached response.

extension Date {
    func toMillis() -> Int64! {
        return Int64(self.timeIntervalSince1970 * 1000)
    }
} 

let currentTimeStamp = Date().toMillis()!
let url = "https://example.com?timestamp=\(currentTimeStamp)"

You can do something like:

var req = URLRequest(url: URL(string: "<URL>")!)
req.httpMethod = "GET"
req.setValue("application/json", forHTTPHeaderField: "Content-Type")
req.setValue("<Auth KEY>", forHTTPHeaderField:"Authorization" )
req.cachePolicy = NSURLRequest.CachePolicy.reloadIgnoringCacheData

 Alamofire.request(req).validate().responseJSON { response in ...

taken from

edited Sep 03 '19 at 10:59

answered Sep 03 '19 at 10:53

Varun Malhotra

1,202
3
15
28

Sorry about the formatting, the code wasn't getting formatted properly – Varun Malhotra Sep 03 '19 at 10:54
the 2nd way, can u give an example on the 1st way – Mohmmad S Sep 03 '19 at 10:56
give me a minute – Varun Malhotra Sep 03 '19 at 10:57
shouldn't my api be supporting a parameter like that ? – Mohmmad S Sep 03 '19 at 11:02
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/198876/discussion-between-varun-malhotra-and-mohmmad-s). – Varun Malhotra Sep 03 '19 at 11:03

score 1 · Answer 2 · answered Sep 03 '19 at 19:23

There are many ways to accomplish this (examples use Alamofire 5):

Use an ephemeral URLSessionConfiguration:

let configuration = URLSessionConfiguration.ephemeral
configuration.headers = .default
let session = Session(configuration: configuration)

Use a URLSessionConfiguration without a URLCache instance:

let configuration = URLSessionConfiguration.af.default
configuration.urlCache = nil
let session = Session(configuration: configuration)

Set an issued URLRequest's cachePolicy to reloadIgnoringLocalCacheData, which should prevent the storing of its response:

var request = URLRequest(...)
request.cachePolicy = .reloadIgnoringLocalCacheData
session.request(request).response...

Use Alamofire 5's CachedResponseHandler API to prevent caching on a per request basis:

session.request(...).cacheResponse(using: ResponseCacher.doNotCache).response...

score 0 · Answer 3 · answered Sep 03 '19 at 11:27

0

-> Did you try removing cacheResponse before requesting again? https://stackoverflow.com/a/47869125/9298652

-> Or try setting NSURLConnectionDelegate's willCacheResponse method to nil to prevent responses from caching.

answered Sep 03 '19 at 11:27

Amyth

383
3
9

how to ignore cached response using Alamofire?

3 Answers3