Trying to cache with Alamofire with no results - swift

Question

I'm trying to use Alamofire Cache, so my desired behavior would be to load the first time from web and next times if data is present on cache return it without make more requests...after I'll think about expiration...
My code returns always response nil...any suggestions on this? Thanks
let config = NSURLSessionConfiguration.defaultSessionConfiguration()
config.URLCache = NSURLCache.sharedURLCache()
config.requestCachePolicy = NSURLRequestCachePolicy.ReturnCacheDataElseLoad
let manager = Alamofire.Manager(configuration: config)
manager.request(.GET, url, parameters: parameters, encoding: .URL, headers: ["Token":LocalStorage.read("token") as! String, "Version":"2"]).responseJSON { (response) in
if let json = response.result.value
{
if response.response?.statusCode == 200
{
completionHandler(parser.parseSwifty(JSON(json)), nil)
}
else
{
completionHandler(nil, serverErrorMessage)
}
}
else
{
completionHandler(nil, networkErrorMessage)
}
}

Answer 1

So...I resolved this issue:
in my NetworkHelper I added a computed property like so:
static let manager: Manager = {
let memoryCapacity = 100 * 1024 * 1024; // 100 MB
let diskCapacity = 100 * 1024 * 1024; // 100 MB
let cache = NSURLCache(memoryCapacity: memoryCapacity, diskCapacity: diskCapacity, diskPath: "shared_cache")
let configuration: NSURLSessionConfiguration = NSURLSessionConfiguration.defaultSessionConfiguration()
configuration.HTTPAdditionalHeaders = ["Token":LocalStorage.read("token") as! String, "Version":"2"]
configuration.requestCachePolicy = .ReturnCacheDataElseLoad // this is the default
configuration.URLCache = cache
return Manager(configuration: configuration)
}()
and when I have to retrieve some data:
self.manager.request(.GET, url, parameters: parameters, encoding: .URL)
.response { (request, response, data, error) in
debugPrint(request)
debugPrint(response)
debugPrint(error)
}.responseJSON......
I also write a func to preload some data like this:
static func preloadGetRequest(url : String, parameters: Dictionary<String, String>?)
{
self.manager.request(.GET, url, parameters: parameters, encoding: .URL)
.response { (request, response, data, error) in
debugPrint(request)
debugPrint(response)
debugPrint(error)
}
}
Try and let me know :)

Answer 2

It seems the correct way is to create Session Manager early on before calling the request or else the request would always returns nil.
var sessionManager: SessionManager!
override func viewDidLoad() {
let configuration = URLSessionConfiguration.default
configuration.requestCachePolicy = .returnCacheDataElseLoad
sessionManager = SessionManager(configuration: configuration)
}
//later on
#objc private func refreshWeatherData(_ sender: Any) {
// Fetch Weather Data
sessionManager.request("https://jsonplaceholder.typicode.com/posts")
.response { (data) in
self.refreshControl?.endRefreshing()
if let data = data.data {
let json = try? JSON(data: data)
}
}
}
or create a URLRequest with caching policy like so
#objc private func refreshWeatherData(_ sender: Any) {
// Fetch Weather Data
let request = URLRequest(url: URL(string: "https://jsonplaceholder.typicode.com/posts")!, cachePolicy: .returnCacheDataElseLoad, timeoutInterval: 100)
Alamofire.request(request)
.response { (data) in
self.refreshControl?.endRefreshing()
if let data = data.data {
let json = try? JSON(data: data)
}
}
}