Network calls

Network API Calls

Step 1¶

Make structure to conform with codable data type

Step 2¶

Make asynchronous network calls with specific URL

Step 3¶

Add header files and authorization to the network request being created and sent over from apple default URLSession

guard let url = URL(string: Constants.baseURL.rawValue + Constants.image.rawValue + value) else { return  }

        // ImageResponse(name: "Billy", url: "https://i.redd.it/vxyig96zgfh61.png", type: "png", width: 400, height: 400)
        // Creating URL Request
        var request = URLRequest(url: url)
        request.httpMethod = "GET"

        // Setting API Key
        request.setValue(Constants.apiKey.rawValue, forHTTPHeaderField: Constants.apiHeader.rawValue)

        let task = URLSession.shared.dataTask(with: request) { (data, response, error) in
            guard error == nil else { return }


            guard let httpResponse = (response as? HTTPURLResponse)?.statusCode, httpResponse == HTTPStatusCode.statusSuccess.rawValue else {
                let httpCode = (response as? HTTPURLResponse )?.statusCode
                print("Error in retrieving data from API", +httpCode!)
                if httpCode == HTTPStatusCode.statusUnauthorized.rawValue {
                    print(Connection.statusUnauthorized.rawValue)
                }
                DispatchQueue.main.async {
                    // TODO: Create a small popup alert stating error in retrieving data so the user is informed with the process.
                }
                return
            }


            guard let data = data else { return }
            do {
                imgResponse = try JSONDecoder().decode(ImageResponse.self, from: data)
                guard let imgResponse = imgResponse else {
                    return
                }
                print(imgResponse.name)
                print(imgResponse.url)
//                return imgResponse
                DispatchQueue.main.async {
                    completionHandler(imgResponse)
//                    return imgResponse
                }
            } catch let error {
                print("Error in retrieving data" + error.localizedDescription)
            }


        }

        // Resume Asynchronous network call
        task.resume()

URL Components¶

public func createSignUpURL(matching clientID: String = "clientID") -> URL {
    var components = URLComponents()
    components.scheme = "https"
    components.host = "qa1.qa.drive.com"
    components.path = "/#/sync"
    components.queryItems = [
    URLQueryItem(name: "client_id", value: clientID)
    ]
    let finalURL = components.string?.removingPercentEncoding ?? "https://qa1.qa.drive.com/#/sync?client_id=clientID"

    return URL(string: finalURL)!
}

https://developer.apple.com/documentation/foundation/urlcomponents

https://www.swiftbysundell.com/articles/constructing-urls-in-swift/

https://www.avanderlee.com/swift/url-components/

Checks¶

Checking if URL is valid form

// Swift 5
func verifyUrl (urlString: String?) -> Bool {
    if let urlString = urlString {
        if let url = NSURL(string: urlString) {
            return UIApplication.shared.canOpenURL(url as URL)
        }
    }
    return false
}

https://stackoverflow.com/questions/28079123/how-to-check-validity-of-url-in-swift

guard let url = URL(string: "http://www.google.com") else {
  return //be safe
}

if #available(iOS 10.0, *) {
    UIApplication.shared.open(url, options: [:], completionHandler: nil)
} else {
    UIApplication.shared.openURL(url)
}

https://stackoverflow.com/questions/39546856/how-to-open-an-url-in-swift https://developer.apple.com/documentation/uikit/uiapplication/1648685-open