Ytukyg

I am making a web request to the Google Places API to fetch nearby places based off a specific coordinate and thereafter run a task to fetch a photo of those places.

I am able to successfully get place details through the first task, and while the second task of retrieving the photo runs, its completion block is never entered resulting in no photo as I have observed placing breakpoints.

The urlString is correct, my apiKey works correctly since again the first task returns the right response, and I have the photo reference of the place to be able to execute the web request. Any guidance would be appreciated as I am admittedly lost - can provide more detail if needed.

Below are the network calls, which is adapted from ray wenderlich's guide.

typealias PlacesCompletion = ([Place]) -> Void

typealias PhotoCompletion = (UIImage?) -> Void



class DataProvider {

    private var photoCache: [String: UIImage] = [:]

    private var placesTask: URLSessionDataTask?

    private var session: URLSession {

        return URLSession.shared

    }



//FIRST WEB REQUEST

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=(googleApiKey)"

    let typesString = "restaurant"

    urlString += "&type=(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: [Place] = 

        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 = Place(dictionary: $0, acceptedTypes: types)

            placesArray.append(place)                



            if let reference = place.photoReference {

                //SECOND WEB REQUEST CALL

                self.fetchPhotoFromReference(reference) { image in

                    place.photo = image

                }

            }

        }

    }

    placesTask?.resume()

}







//SECOND WEB REQUEST

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&maxheight=200&photoreference=(reference)&key=(googleApiKey)"

        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()

    }

}

}

Try removing the session.download(with: url) block. In order to download the data from the url, all you need is let imageData = try? Data(contentsOf: url).

Also, you are not giving the let imageData = try? Data(contentsOf: url) time to execute. You make the call and then immediately try to use the results in the downloadedPhoto = UIImage(data: imageData) line.