So basically I want to make a TableList from my REST service. The REST service can be decoded by this code block:
func getAllParkeergarages(_ completion: #escaping ([Parkeergarage]) -> ()) {
if let url = URL(string: "http://localhost:8080/parkeergarages") {
URLSession.shared.dataTask(with: url) { data, response, error in
if let data = data {
do {
let res = try JSONDecoder().decode([Parkeergarage].self, from: data)
print(res)
completion(res)
return
} catch let error {
print(error)
}
}
}.resume()
}
}
By using this codeblock I can print the whole JSON in my terminal:
getAllParkeergarages { (array) in
print(array)
}
To get the data in a TableView I need to have the data in a variable. But here is where I get stuck. I tried some different methodes like:
private var data: [Parkeergarage] = getAllParkeergarages { (array) in
return array
}
but is gives me an error: 'Cannot convert value of type '()' to specified type '[Parkeergarage]'. Can someone help me get the result of the function in the variable?
you should do
private var data: [Parkeergarage] = []
in viewDidLoad
override func viewDidLoad() {
super.viewDidLoad()
getAllParkeergarages { (array) in
self.data = array
self.tableView.reloadData()
}
}
I cannot explain any more.
I have created a utility class in my Swift project that handles all the REST requests and responses. I have built a simple REST API so I can test my code. I have created a class method that needs to return an NSArray but because the API call is async I need to return from the method inside the async call. The problem is the async returns void.
If I were doing this in Node I would use JS promises but I can't figure out a solution that works in Swift.
import Foundation
class Bookshop {
class func getGenres() -> NSArray {
println("Hello inside getGenres")
let urlPath = "http://creative.coventry.ac.uk/~bookshop/v1.1/index.php/genre/list"
println(urlPath)
let url: NSURL = NSURL(string: urlPath)
let session = NSURLSession.sharedSession()
var resultsArray:NSArray!
let task = session.dataTaskWithURL(url, completionHandler: {data, response, error -> Void in
println("Task completed")
if(error) {
println(error.localizedDescription)
}
var err: NSError?
var options:NSJSONReadingOptions = NSJSONReadingOptions.MutableContainers
var jsonResult = NSJSONSerialization.JSONObjectWithData(data, options: options, error: &err) as NSDictionary
if(err != nil) {
println("JSON Error \(err!.localizedDescription)")
}
//NSLog("jsonResults %#", jsonResult)
let results: NSArray = jsonResult["genres"] as NSArray
NSLog("jsonResults %#", results)
resultsArray = results
return resultsArray // error [anyObject] is not a subType of 'Void'
})
task.resume()
//return "Hello World!"
// I want to return the NSArray...
}
}
You can pass callback, and call callback inside async call
something like:
class func getGenres(completionHandler: (genres: NSArray) -> ()) {
...
let task = session.dataTaskWithURL(url) {
data, response, error in
...
resultsArray = results
completionHandler(genres: resultsArray)
}
...
task.resume()
}
and then call this method:
override func viewDidLoad() {
Bookshop.getGenres {
genres in
println("View Controller: \(genres)")
}
}
Introduced in Swift 5.5 (iOS 15, macOS 12), we would now use the async-await pattern:
func fetchGenres() async throws -> [Genre] {
…
let (data, _) = try await URLSession.shared.dataTask(for: request)
return try JSONDecoder().decode([Genre].self, from: data)
}
And we would call it like:
let genres = try await fetchGenres()
The async-await syntax is far more concise and natural than the traditional completion handler pattern outlined in my original answer, below.
For more information, see Meet async/await in Swift.
The historic pattern is to use completion handlers closure.
For example, we would often use Result:
func fetchGenres(completion: #escaping (Result<[Genre], Error>) -> Void) {
...
URLSession.shared.dataTask(with: request) { data, _, error in
if let error = error {
DispatchQueue.main.async {
completion(.failure(error))
}
return
}
// parse response here
let results = ...
DispatchQueue.main.async {
completion(.success(results))
}
}.resume()
}
And you’d call it like so:
fetchGenres { results in
switch results {
case .failure(let error):
print(error.localizedDescription)
case .success(let genres):
// use `genres` here, e.g. update model and UI
}
}
// but don’t try to use `genres` here, as the above runs asynchronously
Note, above I’m dispatching the completion handler back to the main queue to simplify model and UI updates. Some developers take exception to this practice and either use whatever queue URLSession used or use their own queue (requiring the caller to manually synchronize the results themselves).
But that’s not material here. The key issue is the use of completion handler to specify the block of code to be run when the asynchronous request is done.
Note, above I retired the use of NSArray (we don’t use those bridged Objective-C types any more). I assume that we had a Genre type and we presumably used JSONDecoder, rather than JSONSerialization, to decode it. But this question didn’t have enough information about the underlying JSON to get into the details here, so I omitted that to avoid clouding the core issue, the use of closures as completion handlers.
Swiftz already offers Future, which is the basic building block of a Promise. A Future is a Promise that cannot fail (all terms here are based on the Scala interpretation, where a Promise is a Monad).
https://github.com/maxpow4h/swiftz/blob/master/swiftz/Future.swift
Hopefully will expand to a full Scala-style Promise eventually (I may write it myself at some point; I'm sure other PRs would be welcome; it's not that difficult with Future already in place).
In your particular case, I would probably create a Result<[Book]> (based on Alexandros Salazar's version of Result). Then your method signature would be:
class func fetchGenres() -> Future<Result<[Book]>> {
Notes
I do not recommend prefixing functions with get in Swift. It will break certain kinds of interoperability with ObjC.
I recommend parsing all the way down to a Book object before returning your results as a Future. There are several ways this system can fail, and it's much more convenient if you check for all of those things before wrapping them up into a Future. Getting to [Book] is much better for the rest of your Swift code than handing around an NSArray.
Swift 4.0
For async Request-Response you can use completion handler. See below I have modified the solution with completion handle paradigm.
func getGenres(_ completion: #escaping (NSArray) -> ()) {
let urlPath = "http://creative.coventry.ac.uk/~bookshop/v1.1/index.php/genre/list"
print(urlPath)
guard let url = URL(string: urlPath) else { return }
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
guard let data = data else { return }
do {
if let jsonResult = try JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.mutableContainers) as? NSDictionary {
let results = jsonResult["genres"] as! NSArray
print(results)
completion(results)
}
} catch {
//Catch Error here...
}
}
task.resume()
}
You can call this function as below:
getGenres { (array) in
// Do operation with array
}
Swift 3 version of #Alexey Globchastyy's answer:
class func getGenres(completionHandler: #escaping (genres: NSArray) -> ()) {
...
let task = session.dataTask(with:url) {
data, response, error in
...
resultsArray = results
completionHandler(genres: resultsArray)
}
...
task.resume()
}
Swift 5.5, async/wait-based solution
The original test URL provided by the original poster is no longer functional, so I had to change things a bit. This solution is based on a jokes API I found. That API returns a single joke, but I return it as an array of String ([String]), to keep it as consistent as possible with the original post.
class Bookshop {
class func getGenres() async -> [String] {
print("Hello inside getGenres")
let urlPath = "https://geek-jokes.sameerkumar.website/api?format=json"
print(urlPath)
let url = URL(string: urlPath)!
let session = URLSession.shared
typealias Continuation = CheckedContinuation<[String], Never>
let genres = await withCheckedContinuation { (continuation: Continuation) in
let task = session.dataTask(with: url) { data, response, error in
print("Task completed")
var result: [String] = []
defer {
continuation.resume(returning: result)
}
if let error = error {
print(error.localizedDescription)
return
}
guard let data = data else {
return
}
do {
let jsonResult = try JSONSerialization.jsonObject(with: data, options: [.mutableContainers])
print("jsonResult is \(jsonResult)")
if let joke = (jsonResult as? [String: String])?["joke"] {
result = [joke]
}
} catch {
print("JSON Error \(error.localizedDescription)")
print("data was \(String(describing: String(data: data, encoding: .utf8)))")
return
}
}
task.resume()
}
return genres
}
}
async {
let final = await Bookshop.getGenres()
print("Final is \(final)")
}
The withCheckedContinuation is how you made the Swift async function actually run in a separate task/thread.
I hope you're not still stuck on this, but the short answer is that you can't do this in Swift.
An alternative approach would be to return a callback that will provide the data you need as soon as it is ready.
There are 3 ways of creating call back functions namely:
1. Completion handler
2. Notification
3. Delegates
Completion Handler
Inside set of block is executed and returned when source is available, Handler will wait until response comes so that UI can be updated after.
Notification
Bunch of information is triggered over all the app, Listner can retrieve n make use of that info. Async way of getting info through out the project.
Delegates
Set of methods will get triggered when delegate is been called, Source must be provided via methods itself
Swift 5.5:
TL;DR: Swift 5.5 is not yet released(at the time of writing). To use swift 5.5, download swift toolchain development snapshot from here and add compiler flag -Xfrontend -enable-experimental-concurrency. Read more here
This can be achieved easily with async/await feature.
To do so, you should mark your function as async then do the operation inside withUnsafeThrowingContinuation block like following.
class Bookshop {
class func getGenres() async throws -> NSArray {
print("Hello inside getGenres")
let urlPath = "http://creative.coventry.ac.uk/~bookshop/v1.1/index.php/genre/list"
print(urlPath)
let url = URL(string: urlPath)!
let session = URLSession.shared
return try await withUnsafeThrowingContinuation { continuation in
let task = session.dataTask(with: url, completionHandler: {data, response, error -> Void in
print("Task completed")
if(error != nil) {
print(error!.localizedDescription)
continuation.resume(throwing: error!)
return
}
do {
let jsonResult = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? [String: Any]
let results: NSArray = jsonResult!["genres"] as! NSArray
continuation.resume(returning: results)
} catch {
continuation.resume(throwing: error)
}
})
task.resume()
}
}
}
And you can call this function like
#asyncHandler
func check() {
do {
let genres = try await Bookshop.getGenres()
print("Result: \(genres)")
} catch {
print("Error: \(error)")
}
}
Keep in mind that, when calling Bookshop.getGenres method, the caller method should be either async or marked as #asyncHandler
self.urlSession.dataTask(with: request, completionHandler: { (data, response, error) in
self.endNetworkActivity()
var responseError: Error? = error
// handle http response status
if let httpResponse = response as? HTTPURLResponse {
if httpResponse.statusCode > 299 , httpResponse.statusCode != 422 {
responseError = NSError.errorForHTTPStatus(httpResponse.statusCode)
}
}
var apiResponse: Response
if let _ = responseError {
apiResponse = Response(request, response as? HTTPURLResponse, responseError!)
self.logError(apiResponse.error!, request: request)
// Handle if access token is invalid
if let nsError: NSError = responseError as NSError? , nsError.code == 401 {
DispatchQueue.main.async {
apiResponse = Response(request, response as? HTTPURLResponse, data!)
let message = apiResponse.message()
// Unautorized access
// User logout
return
}
}
else if let nsError: NSError = responseError as NSError? , nsError.code == 503 {
DispatchQueue.main.async {
apiResponse = Response(request, response as? HTTPURLResponse, data!)
let message = apiResponse.message()
// Down time
// Server is currently down due to some maintenance
return
}
}
} else {
apiResponse = Response(request, response as? HTTPURLResponse, data!)
self.logResponse(data!, forRequest: request)
}
self.removeRequestedURL(request.url!)
DispatchQueue.main.async(execute: { () -> Void in
completionHandler(apiResponse)
})
}).resume()
There are mainly 3 ways of achieving callback in swift
Closures/Completion handler
Delegates
Notifications
Observers can also be used to get notified once the async task has been completed.
There are some very generic requirements that would like every good API Manager to satisfy:
will implement a protocol-oriented API Client.
APIClient Initial Interface
protocol APIClient {
func send(_ request: APIRequest,
completion: #escaping (APIResponse?, Error?) -> Void)
}
protocol APIRequest: Encodable {
var resourceName: String { get }
}
protocol APIResponse: Decodable {
}
Now Please check complete api structure
// ******* This is API Call Class *****
public typealias ResultCallback<Value> = (Result<Value, Error>) -> Void
/// Implementation of a generic-based API client
public class APIClient {
private let baseEndpointUrl = URL(string: "irl")!
private let session = URLSession(configuration: .default)
public init() {
}
/// Sends a request to servers, calling the completion method when finished
public func send<T: APIRequest>(_ request: T, completion: #escaping ResultCallback<DataContainer<T.Response>>) {
let endpoint = self.endpoint(for: request)
let task = session.dataTask(with: URLRequest(url: endpoint)) { data, response, error in
if let data = data {
do {
// Decode the top level response, and look up the decoded response to see
// if it's a success or a failure
let apiResponse = try JSONDecoder().decode(APIResponse<T.Response>.self, from: data)
if let dataContainer = apiResponse.data {
completion(.success(dataContainer))
} else if let message = apiResponse.message {
completion(.failure(APIError.server(message: message)))
} else {
completion(.failure(APIError.decoding))
}
} catch {
completion(.failure(error))
}
} else if let error = error {
completion(.failure(error))
}
}
task.resume()
}
/// Encodes a URL based on the given request
/// Everything needed for a public request to api servers is encoded directly in this URL
private func endpoint<T: APIRequest>(for request: T) -> URL {
guard let baseUrl = URL(string: request.resourceName, relativeTo: baseEndpointUrl) else {
fatalError("Bad resourceName: \(request.resourceName)")
}
var components = URLComponents(url: baseUrl, resolvingAgainstBaseURL: true)!
// Common query items needed for all api requests
let timestamp = "\(Date().timeIntervalSince1970)"
let hash = "\(timestamp)"
let commonQueryItems = [
URLQueryItem(name: "ts", value: timestamp),
URLQueryItem(name: "hash", value: hash),
URLQueryItem(name: "apikey", value: "")
]
// Custom query items needed for this specific request
let customQueryItems: [URLQueryItem]
do {
customQueryItems = try URLQueryItemEncoder.encode(request)
} catch {
fatalError("Wrong parameters: \(error)")
}
components.queryItems = commonQueryItems + customQueryItems
// Construct the final URL with all the previous data
return components.url!
}
}
// ****** API Request Encodable Protocol *****
public protocol APIRequest: Encodable {
/// Response (will be wrapped with a DataContainer)
associatedtype Response: Decodable
/// Endpoint for this request (the last part of the URL)
var resourceName: String { get }
}
// ****** This Results type Data Container Struct ******
public struct DataContainer<Results: Decodable>: Decodable {
public let offset: Int
public let limit: Int
public let total: Int
public let count: Int
public let results: Results
}
// ***** API Errro Enum ****
public enum APIError: Error {
case encoding
case decoding
case server(message: String)
}
// ****** API Response Struct ******
public struct APIResponse<Response: Decodable>: Decodable {
/// Whether it was ok or not
public let status: String?
/// Message that usually gives more information about some error
public let message: String?
/// Requested data
public let data: DataContainer<Response>?
}
// ***** URL Query Encoder OR JSON Encoder *****
enum URLQueryItemEncoder {
static func encode<T: Encodable>(_ encodable: T) throws -> [URLQueryItem] {
let parametersData = try JSONEncoder().encode(encodable)
let parameters = try JSONDecoder().decode([String: HTTPParam].self, from: parametersData)
return parameters.map { URLQueryItem(name: $0, value: $1.description) }
}
}
// ****** HTTP Pamater Conversion Enum *****
enum HTTPParam: CustomStringConvertible, Decodable {
case string(String)
case bool(Bool)
case int(Int)
case double(Double)
init(from decoder: Decoder) throws {
let container = try decoder.singleValueContainer()
if let string = try? container.decode(String.self) {
self = .string(string)
} else if let bool = try? container.decode(Bool.self) {
self = .bool(bool)
} else if let int = try? container.decode(Int.self) {
self = .int(int)
} else if let double = try? container.decode(Double.self) {
self = .double(double)
} else {
throw APIError.decoding
}
}
var description: String {
switch self {
case .string(let string):
return string
case .bool(let bool):
return String(describing: bool)
case .int(let int):
return String(describing: int)
case .double(let double):
return String(describing: double)
}
}
}
/// **** This is your API Request Endpoint Method in Struct *****
public struct GetCharacters: APIRequest {
public typealias Response = [MyCharacter]
public var resourceName: String {
return "characters"
}
// Parameters
public let name: String?
public let nameStartsWith: String?
public let limit: Int?
public let offset: Int?
// Note that nil parameters will not be used
public init(name: String? = nil,
nameStartsWith: String? = nil,
limit: Int? = nil,
offset: Int? = nil) {
self.name = name
self.nameStartsWith = nameStartsWith
self.limit = limit
self.offset = offset
}
}
// *** This is Model for Above Api endpoint method ****
public struct MyCharacter: Decodable {
public let id: Int
public let name: String?
public let description: String?
}
// ***** These below line you used to call any api call in your controller or view model ****
func viewDidLoad() {
let apiClient = APIClient()
// A simple request with no parameters
apiClient.send(GetCharacters()) { response in
response.map { dataContainer in
print(dataContainer.results)
}
}
}
This is a small use case that might be helpful:-
func testUrlSession(urlStr:String, completionHandler: #escaping ((String) -> Void)) {
let url = URL(string: urlStr)!
let task = URLSession.shared.dataTask(with: url){(data, response, error) in
guard let data = data else { return }
if let strContent = String(data: data, encoding: .utf8) {
completionHandler(strContent)
}
}
task.resume()
}
While calling the function:-
testUrlSession(urlStr: "YOUR-URL") { (value) in
print("Your string value ::- \(value)")
}
I have such array in from api:
[{
data = "";
datetime = "23.07.2020 12:09";
id = 340593;
status = "My current task is";
},...]
I have created such struct:
struct RemarksModel {
let id:Int
let status,datetime:String
let data:String?
}
And here I make request:
AF.request(URLRequest(url:Pathes.init(endpoint: "notepad/\(noteModel?.id ?? 0)/documentation").resourseUrl),
interceptor: CallInterceptor.init(method:HTTPMethod.get)).responseJSON(completionHandler: { (response) in
print(response.description)
switch response.result{
case .success(let array):
let remarksData = array as? [RemarksModel]
let json = response.data as? [RemarksModel]
print(json?.count)
// if remarksData?.count ?? 1 > 0{
// self.remarksArray += remarksData!
// self.tableView.reloadData()
// }
case .failure(let error):
print(error.localizedDescription)
}
})
the problem is that I can't convert this array to array of my model objects. when I try to add all received data to array my app crashes because my array is nil, despite of json in logs. Maybe I have to use another way of converting received json array to objects array?
You can use directly .responseDecodable function instead of .responseData or .responseJSON after confirming RemarksModel to Codable (or just Decodable) protocol
.responseDecodable(of: [RemarksModel].self, queue: .main, decoder: JSONDecoder()) { (response) in
switch response.result {
case let .success(data):
// success
print(data)
case let .failure(error):
// error
print(error.localizedDescription)
}
}
You can add Codable protocol to RemarksModel and use .responseData instead of .responseJSON
.responseData { response in
switch response.result {
case let .success(data):
do {
let result = try JSONDecoder().decode([RemarksModel].self, from: data)
// success
} catch {
print("decoding error:\n\(error)")
// error
}
case let .failure(error):
// error
}
}
I would like to return an array (arr) from method (with async call). I implement the completionHandler in the method, but I can't use my method to get my array : Cast from '(#escaping ((Array<Any>) -> Void)) -> ()' to unrelated type '[[String : Any]]' always fails
How can I fix this ?
Here is my code :
func dataWithURL(completion: #escaping ((_ result:Array<Any>) -> Void)) {
let urlString = "https://api.unsplash.com/photos/?client_id=71ad401443f49f22556bb6a31c09d62429323491356d2e829b23f8958fd108c4"
let url = URL(string: urlString)!
let urlRequest = URLRequest(url: url)
let config = URLSessionConfiguration.default
let session = URLSession(configuration: config)
var arr = [[String:String]]()
let task = session.dataTask(with: urlRequest, completionHandler: { (data, response, error) in
// do stuff with response, data & error here
if let statusesArray = try? JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [[String: Any]] {
for item in statusesArray! {
let photos = item["urls"] as? [String: Any]
let photo = photos?["small"] as? String
let myDictionary = [
"name": "test",
"imageURL": photo]
arr.append(myDictionary as! [String : String])
}
print(arr)
completion(arr)
}
})
task.resume()
}
And when I want to get my array :
lazy var photos: [Photo] = {
var photos = [Photo]()
// HERE THE ERROR APPEARS
guard let data = self.dataWithURL as? [[String: Any]] else { return photos }
for info in data {
let photo = Photo(info: info)
photos.append(photo)
}
return photos
}()
dataWithURL takes in a callback (completion handler), therefore you can only access the results in the callback.
self.dataWithURL { result in
//do stuff with the result
}
However the problem with the code above is that you are expecting dataWithURL to return the results which it doesn't. It returns void.
Another problem is that you are trying to use the results of dataWithURL for a property. The call to access the lazy var photos would yield no result (at least on first invocation) because the call dataWithURL is async (returns immediately).
You seem to be also xcode_Dev having asked this question yesterday.
I wrote a comment to that question:
You cannot return something from a function (or computed variable) which contains an asynchronous task
This is still true.
dataWithURL is an asynchronous function, it does not return anything but you have to pass a closure which is called on return.
First of all, the array is clearly [[String:String]] (array of dictionaries with string keys and string values) so it's pretty silly to use the much more unspecified type [Any]
func dataWithURL(completion: #escaping ([[String:String]]) -> Void) {
In Swift 3 specify only the type in the declaration without underscores and parameter labels.
You have to call the function this way:
dataWithURL { result in
for item in result { // the compiler knows the type
print(item["name"], item["imageURL"])
}
}
Once again: There is no return value of dataWithURL. The closure is called later.
I am a beginner in swift and I have come across a case where I need to run AlamoFire GET request in a loop. But As far as i know , the Alamofire Get request is an Asynchronous call and calling it in loop will create a number of threads.
The requirement is :
I have an array of URLs
The array has to be traversed in a loop
URL on each index has to be called through AlamoFire GET request
The received data through the request will be added to an array of
data
After the last data is saved in the array, a
CollectionView.reload call should be called
Pseudo code is as follows:
for bookmarkURL in bookmarks
Alamofire.request(.GET, bookmarkURL ).responseJSON
{ response in switch response.result {
case .Success(let JSON):
x[i] = JSON as! [String : AnyObject] // saving data
case .Failure(let error):
print("the error for \(self.bookmarkURL) is \(error) ")
}
i++
if i == bookmarks.count{
collectionView.reload()
break}
}
can anyone tell me how should I do it in sequence?
Make bookmarks array as class property.
Add a class property index to store index value (Int) while traversing the bookmarks array
Add a function to make API call and call it recursively.
Here is the code:
func getData() {
var x = [[String: AnyObject]]()
Alamofire.request(.GET, bookmarks[index]).responseJSON { response in
switch response.result {
case .Success(let JSON):
x[self.index] = JSON as! [String : AnyObject] // saving data
self.index = self.index + 1
if self.index < self.bookmarks.count {
self.getData()
}else {
self.collectionView.reloadData()
}
case .Failure(let error):
print("the error for \(self.bookmarks[self.index]) is \(error) ")
if self.index < self.bookmarks.count {
self.getData()
}else {
self.collectionView.reloadData()
}
}
}
}
In this way your request will be made only when previous is completed thus making it sequentially instead of parallel and you can also reload the collectionView only after the last request is completed.
If you want to reload your collection view only after receiving whole the data, you can use dispatch_group like,
let group = dispatch_group_create() // create a group.
dispatch_group_enter(group) // enter the group just before create the request
dispatch_group_leave(group)//leave the group on completion closure
dispatch_group_notify(group, group) {
//reload your collection view
}
Full code
for bookmarkURL in bookmarks {
dispatch_group_enter(group)
Alamofire.request(.GET, bookmarkURL ).responseJSON { response in
switch response.result {
case .Success(let JSON):
x[i] = JSON as! [String : AnyObject] // saving data
case .Failure(let error):
print("the error for \(self.bookmarkURL) is \(error) ")
}
dispatch_group_leave(group)
}
}
dispatch_group_notify(group, group) {
collectionView.reload()
}
Note: if your bookmarks array is too large, better not to do it in a loop.
For that you can use following code
func loadBookmarkAtIndex(index: Int) {
if index >= bookmarks.count {
collectionView.reload()
return
}
let bookmarkURL = bookmarks[index]
Alamofire.request(.GET, bookmarkURL ).responseJSON { response in
switch response.result {
case .Success(let JSON):
x[index] = JSON as! [String : AnyObject] // saving data
case .Failure(let error):
print("the error for \(bookmarkURL) is \(error) ")
}
self.loadBookmarkAtIndex(index+1)
}
}
And call self.loadBookmarkAtIndex(0) from where you are initiating the data retrieve.
I think you should reload item of collection view each time you get the response from the sever regarding to the response received.
Here is the solution:
let x : NSMutableArray = NSMutableArray.init(capacity: bookmarks.count)
for var i in 0 ..< x.count {
Alamofire.request(.GET, bookmarkURL ).responseJSON
{ response in switch response.result {
case .Success(let JSON):
x.insertObject(JSON as! [String : AnyObject], atIndex:i)
// x[i] = // saving data
// <reload relative item cell of collectionView>
case .Failure(let error):
print("the error for \(self.bookmarkURL) is \(error) ")
}
i+=1
}
Hope above code will help you.