Converting Swift ios Networking to use Alamofire

Question

I got a source code from a github page written in swift and implementing GoogleMaps. I now want to refactor the codes to use Alamofire and SwiftyJSON so that I can improve the code but I got confused because through my learning of swift I used Alamofire and swiftyJSON for every networking process so I am confused currently. the code below

typealias PlacesCompletion = ([GooglePlace]) -> Void
typealias PhotoCompletion = (UIImage?) -> Void


    class GoogleDataProvider {
        private var photoCache: [String: UIImage] = [:]
        private var placesTask: URLSessionDataTask?
        private var session: URLSession {
            return URLSession.shared
        }

        let appDelegate = UIApplication.shared.delegate as! AppDelegate

        func fetchPlacesNearCoordinate(_ coordinate: CLLocationCoordinate2D, radius: Double, types:[String], completion: @escaping PlacesCompletion) -> Void {
            var urlString = "https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=\(coordinate.latitude),\(coordinate.longitude)&radius=\(radius)&rankby=prominence&sensor=true&key=\(appDelegate.APP_ID)"

            let typesString = types.count > 0 ? types.joined(separator: "|") : "food"
            urlString += "&types=\(typesString)"
            urlString = urlString.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed) ?? urlString

            guard let url = URL(string: urlString) else {
                completion([])
                return
            }

            if let task = placesTask, task.taskIdentifier > 0 && task.state == .running {
                task.cancel()
            }

            DispatchQueue.main.async {
                UIApplication.shared.isNetworkActivityIndicatorVisible = true
            }

            placesTask = session.dataTask(with: url) { data, response, error in
                var placesArray: [GooglePlace] = []
                defer {
                    DispatchQueue.main.async {
                        UIApplication.shared.isNetworkActivityIndicatorVisible = false
                        completion(placesArray)
                    }
                }
                guard let data = data,
                    let json = try? JSON(data: data, options: .mutableContainers),
                    let results = json["results"].arrayObject as? [[String: Any]] else {
                        return
                }
                results.forEach {
                    let place = GooglePlace(dictionary: $0, acceptedTypes: types)
                    placesArray.append(place)
                    if let reference = place.photoReference {
                        self.fetchPhotoFromReference(reference) { image in
                            place.photo = image
                        }
                    }
                }
            }
            placesTask?.resume()
        }


        func fetchPhotoFromReference(_ reference: String, completion: @escaping PhotoCompletion) -> Void {
            if let photo = photoCache[reference] {
                completion(photo)
            } else {
                let urlString = "https://maps.googleapis.com/maps/api/place/photo?maxwidth=200&photoreference=\(reference)&key=\(appDelegate.APP_ID)"
                guard let url = URL(string: urlString) else {
                    completion(nil)
                    return
                }

                DispatchQueue.main.async {
                    UIApplication.shared.isNetworkActivityIndicatorVisible = true
                }

                session.downloadTask(with: url) { url, response, error in
                    var downloadedPhoto: UIImage? = nil
                    defer {
                        DispatchQueue.main.async {
                            UIApplication.shared.isNetworkActivityIndicatorVisible = false
                            completion(downloadedPhoto)
                        }
                    }
                    guard let url = url else {
                        return
                    }
                    guard let imageData = try? Data(contentsOf: url) else {
                        return
                    }
                    downloadedPhoto = UIImage(data: imageData)
                    self.photoCache[reference] = downloadedPhoto
                    }
                    .resume()
            }
        }
    }

any help to refactor the codes to use Alamofire and swiftyJSON would be appreciated.

Answer 1

Both Alamofire and SwiftyJSON have pretty decent instructions, and there are plenty of examples online to look for. However, this would be a decent starting point - you need to replace your session.dataTask and session.downloadTask with Alamofire methods. For example, instead of:

session.downloadTask(with: url) { url, response, error in
                var downloadedPhoto: UIImage? = nil
                defer {
                    DispatchQueue.main.async {
                        UIApplication.shared.isNetworkActivityIndicatorVisible = false
                        completion(downloadedPhoto)
                    }
                }
                guard let url = url else {
                    return
                }
                guard let imageData = try? Data(contentsOf: url) else {
                    return
                }
                downloadedPhoto = UIImage(data: imageData)
                self.photoCache[reference] = downloadedPhoto
                }
                .resume()

use this skeleton and implement your models and logic:

Alamofire
    .request(url)
    .responseJSON { dataResponse in
        switch dataResponse.result {
        case .success:
            guard let json = JSON(dataResponse.data) else {
                return
            }

            // Continue parsing
        case .failure(let error):
            // Handle error
            print("\(error)")
        }
    }