I try to use Alamofire.SessionManager for retry request and offline manager, and I get problem with catch offile mode.
If I use request like this:
Alamofire.SessionManager.default.request("www.google.pl").responseData(queue: queue) { (data) in
print(data)
}
When is no internet connection, data doesn't print (response Data handler doesn't call) and if it is connected, work perfectly.
Related
I am attempting to subscribe to a websocket feed using Swift. Per the new Coinbase Pro API documentation for their websocket feed:
To begin receiving feed messages, you must first send a subscribe message to the server indicating which channels and products to receive. This message is mandatory — you will be disconnected if no subscribe has been received within 5 seconds.
The first thing I did was add Starscream to the project to make connecting to websockets easier to implement. I followed the steps on the README and added the delegate methods appropriately.
Next, I successfully sent an HTTP GET request (I get a 200 code in response) by creating a URLSession object and calling dataTask(with: ) after setting up a request, like so:
let session = URLSession.shared
guard let url = URL(string: "https://api.pro.coinbase.com/users/self/verify") else {
print("Could not create URL.")
return
}
var request = URLRequest(url: url)
request.httpMethod = "GET"
let body: [String: Any] = ["type": "subscribe",
"channels": [["name": "heartbeat"],
["product_ids": ["BTC-USD"]]]]
let data = try! JSONSerialization.data(withJSONObject: body,
options: JSONSerialization.WritingOptions.sortedKeys)
request.httpBody = data
let task = session.dataTask(with: request) { (data, response, error) in
// Check for errors, clean up data, etc.
}
task.resume
Everything appears to be linked up correctly, but I am still not receiving the "subscription" messages from the websocket feed. What am I missing?
I'm using swiftHTTP for requesting to my server and when my internet connection is slow, it goes to response part! I've set the example code below:
HTTP.GET("myURL") { response in
let myResponse = response.data // it comes here after the timeout
if response.statusCode == 200 {
//some code
} else {
do {
let jsonError = try JSON(data: myResponse) // in this line it goes to catch because there is no data in myresponse
} catch{
//alert for not having connection
}
}
Why does it call the response function if there's no response?
My server also says, that no request was sent.
It doesn't "go to response", it tries to make the HTTP request as expected and regardless of success or error it's completion handler is called.
The response object that is returned is an object that contains all of the information you need to determine what happened with the request.
So it will contain a timeout status code (HTTP 408), possibly an error message. If it did not respond at all, your app would not be able to handle these cases.
Say for example your user taps on their profile icon in the app and this sends a request to get the users profile, but it timed out. Do you want the user sat waiting, looking at a blank profile screen? It's much better to catch the error and handle it gracefully. In this case you could present a message to the user telling them that something went wrong and close the empty profile screen
Your response handler will also be called from swiftHTTP, if there's no or a very bad connection.To solve this problem, either check if there is an internet connection or check if the data is nil:
HTTP.GET("myURL") { response in
let myResponse = response.data // it comes here after the timeout
if response.statusCode == 200 || response.data == nil {
//some code
} else {
do {
let jsonError = try JSON(data: myResponse) // in this line it goes to catch because there is no data in myresponse
} catch{
//alert for not having connection
}
}
The important part here is the check if response.data == nil.
When I send first request and then again I send a second request, Alamofire cancels the first request and gives error as -999 Canceled on it.
What is the way to solve so that both request get processed?
So what I want to do is, user clicks on a button one request is sent, and before that request has completed user clicks on the button again. This behaviour cancels the earlier request, rather what I want it do is, when the button is clicked and the request is sent, it should check whether the previous request is completed or still running. If it is completed then the request should process normally but if the previous request is not completed it should wait for the request to complete and once that is completed this request should be sent
self.alamoFireManager.request(request )
.responseJSON { response in
print(response.request) // original URL request
print(response.response) // URL response
print(response.data) // server data
print(response.result) // result of response serialization
guard response.result.error == nil else {
// got an error in getting the data, need to handle it
print("error calling GET on page")
print(response.result.error!)
print("Failure")
if( response.result.error?.code == -999 )
{
print("Previous Query is still Executing")
return
}
I'm using Alamofire with Swift kind of this way:
Alamofire.request(.GET, urlString)
.authenticate(usingCredential: credential)
.response {
(request, responseJSON, data, error) in [..and so on]
Now I wonder how I can execute some code in case the server is e.g. completely down. Something like a failed block in ObjC.
I know that I can call something like this to get an error code:
if let response = responseJSON {
var statusCode = response.statusCode
println("-->statusCode: \(statusCode)")
}
But in the case that I can't reach the server, the .response closure won't execute, so there is no error message.
How is this handled?
If you can't reach the server, you will receive a NSURLErrorDomain error via the error variable in the closure.
I have a method which handles a Apple Push Notification Service remote notification. When this method is executed, I want it to call my server and do a HTTP POST request using the Alamofire library. I want to execute another method that will handle the response of the POST request.
The problem for me is that I am using an existing API to fetch a profile from the server in this POST request. So I need to use this existing API and figure out when this profile fetch is specifically triggered from the remote notification.
Since Alamofire requests are done in a background queue, how would I go about doing an execution of a method after receiving the profile back from the server?
What would be a good option to solving this issue?
Thank you!
Since Alamofire requests are done in a background queue, how would I go about doing an execution of a method after receiving the profile back from the server?
Response handling is built in to Alamofire. You can do something like this (adapted from the docs):
Alamofire.request(.POST, "http://httpbin.org/get", parameters: ["foo": "bar"])
.response { (request, response, data, error) in
println(request)
println(response)
println(error)
}
Note the .response method call, which adds a completion handler to the request object; the completion handler is invoked by Alamofire when the request completes (or fails).
It wasn't clear from your question formulation what problem you were trying to solve. But you've clarified your intent in the question comments above.
As I understand the problem now, you're got some code that updates a profile on the server and handles the server's response. The code is called in two contexts, one initiated by a manual request from the user, another initiated by a push notification. In the first case, you don't want to generate an alert after you process the response from the server, but in the second case you do.
You do indeed have a closure that you can use to handle the different behavior even though the difference happens in the asynchronous part of the process. Here's a sketch (not actual working code) of how that might look:
func updateProfile(parameters: [String:String], showAlert: Bool) {
Alamofire.request(.POST, "http://myserver.com/profile", parameters: parameters)
.response { (request, response, data, error) in
if (error == nil) {
processProfileResponse(response)
if showAlert {
showProfileWasUpdatedAlert()
}
}
}
}
Note the showAlert parameter passed in to the updateProfile method. If you pass in true, it calls the showProfileWasUpdatedAlert method to show your alert after receiving the server's response. Note that this boolean value is "captured" by the closure that handles the Alamofire response because the closure was defined inside the updateProfile function.
This, IMHO, is a better approach than declaring an app global inside your AppDelegate.
Here you go
func AlamofireRequest(method: Alamofire.Method, URLString: URLStringConvertible, parameters: [String : AnyObject]?, encoding: ParameterEncoding, headers: [String : String]?) -> Alamofire.Result<String>? {
var finishFlag = 0
var AlamofireResult: Alamofire.Result<String>? = nil
Alamofire.request(method, URLString, parameters: parameters, encoding: encoding, headers: headers)
.responseString { (_, _, result) -> Void in
if result.isSuccess {
finishFlag = 1
AlamofireResult = result
}
else {
finishFlag = -1
}
}
while finishFlag == 0 {
NSRunLoop.currentRunLoop().runMode(NSDefaultRunLoopMode, beforeDate: NSDate.distantFuture())
}
return AlamofireResult
}