Swift - Multiple URL Request - Code To Refactor and To Reuse - swift

Question

I'm new to Swift and I am trying to refactor my URL Post requests. I have multiple URL POST requests inside the same View Controller like this. Everything works fine but it seems to me that there is a lot of repetitive code that could be reused. Particularly, I don't know how to pass/handle different Data Models that should be used in parseRequest1 and parseRequest2. I also read that there should be only one session used for URL requests within the same project. Any help would be greatly appreciate it!
func request1() {
let parameters = [...//some parameters to send]
guard let url = URL(string: "https//www.....") else {return}
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
guard let parametersToSend = try? JSONSerialization.data(withJSONObject: parameters, options: [])
else {
print("Error")
return
}
request.httpBody = parametersToSend
let session = URLSession.shared
session.dataTask(with: request) { (data, response, error) in
if let safeData = data {
self.parseRequest1(data: safeData)
}
}.resume()
}
func parseRequest1(data: Data){
let decoder = JSONDecoder()
do{
let decodedData = try decoder.decode(DataModelForRequest1.self, from: data)
DispatchQueue.main.async {
self.performAction1(request1Result)
}
} catch {
print(error)
}
}
Then I have another URL request request2 which is almost identical except the parameters, and model to be used for decoding and action inside parseRequest2.
func request2() {
let parameters = [...//some parameters to send]
guard let url = URL(string: "https//www.....") else {return}
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
guard let parametersToSend = try? JSONSerialization.data(withJSONObject: parameters, options: [])
else {
print("Error")
return
}
request.httpBody = parametersToSend
let session = URLSession.shared
session.dataTask(with: request) { (data, response, error) in
if let safeData = data {
self.parseRequest2(data: safeData)
}
}.resume()
}
func parseRequest2(data: Data){
let decoder = JSONDecoder()
do{
let decodedData = try decoder.decode(DataModelForRequest2.self, from: data)
DispatchQueue.main.async {
self.performAction2(request2Result)
}
} catch {
print(error)
}
}

Answer 1

The only differences seem to be:
request parameters
type of model returned
the action you do after the response is received
This means that we can write this as one single method taking the above three values as parameters:
func request<T: Codable>(modelType: T.Type, parameters: [String: Any], completion: (T) -> Void) {
func parseResponse(data: Data){
let decoder = JSONDecoder()
do{
let decodedData = try decoder.decode(T.self, from: data)
DispatchQueue.main.async {
completion(decodedData)
}
} catch {
print(error)
}
}
guard let url = URL(string: "https//www.....") else {return}
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
guard let parametersToSend = try? JSONSerialization.data(withJSONObject: parameters, options: [])
else {
print("Error")
return
}
request.httpBody = parametersToSend
let session = URLSession.shared
session.dataTask(with: request) { (data, response, error) in
if let safeData = data {
parseResponse(data: safeData)
}
}.resume()
}
You can then call this method with the appropriate parameters as per your needs.