Make REST API call in Swift

Question

I\'m trying to use Swift to make a GET call to a REST API, and have tried to follow numerous tutorials, but can\'t figure it out. Either because I cannot figure out how to

Answer 1

Swift 5

API call method

//Send Request with ResultType
    func fetch(requestURL:URL,requestType:String,parameter:[String:AnyObject]?,completion:@escaping (Result) -> () ){
        //Check internet connection as per your convenience
        //Check URL whitespace validation as per your convenience
        //Show Hud
        var urlRequest = URLRequest.init(url: requestURL)
        urlRequest.cachePolicy = .reloadIgnoringLocalCacheData
        urlRequest.timeoutInterval = 60
        urlRequest.httpMethod = String(describing: requestType)
        urlRequest.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
        urlRequest.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Accept")
        
        //Post URL parameters set as URL body
        if let params = parameter{
            do{
                let parameterData = try JSONSerialization.data(withJSONObject:params, options:.prettyPrinted)
                urlRequest.httpBody = parameterData
            }catch{
               //Hide hude and return error
                completion(.failure(error))
            }
        }
        //URL Task to get data
        URLSession.shared.dataTask(with: requestURL) { (data, response, error) in
            //Hide Hud
            //fail completion for Error
            if let objError = error{
                completion(.failure(objError))
            }
            //Validate for blank data and URL response status code
            if let objData = data,let objURLResponse = response as? HTTPURLResponse{
                //We have data validate for JSON and convert in JSON
                do{
                    let objResposeJSON = try JSONSerialization.jsonObject(with: objData, options: .mutableContainers)
                    //Check for valid status code 200 else fail with error
                    if objURLResponse.statusCode == 200{
                        completion(.success(objResposeJSON))
                    }
                }catch{
                    completion(.failure(error))
                }
            }
        }.resume()
    }

Use of API call method

func useOfAPIRequest(){
        if let baseGETURL = URL(string:"https://postman-echo.com/get?foo1=bar1&foo2=bar2"){
            self.fetch(requestURL: baseGETURL, requestType: "GET", parameter: nil) { (result) in
                      switch result{
                      case .success(let response) :
                        print("Hello World \(response)")
                      case .failure(let error) :
                        print("Hello World \(error)")
                          
                      }
                  }
        }
      
    }