[MEDIUM] Strava API - Access & Refresh token - iOS 13, Swift 5 - Step 2

ViewController.swift

import UIKit
import AuthenticationServices

class ViewController: UIViewController {
    
    private var authSession: ASWebAuthenticationSession?
    
    private let clientId: String = "11111"
    private let urlScheme: String = "youUrlScheme"
    private let fallbackUrl: String = "yourFallbackUrl.com"
    
    @IBAction private func connectToStrava(_ sender: UIButton) {
        presentStravaAuthentication()
    }
    
    private func presentStravaAuthentication() {
        let url: String = "https://www.strava.com/oauth/mobile/authorize?client_id=\(clientId)&redirect_uri=\(urlScheme)%3A%2F%2F\(fallbackUrl)&response_type=code&approval_prompt=auto&scope=read"
        guard let authenticationUrl = URL(string: url) else { return }
        
        authSession = ASWebAuthenticationSession(url: authenticationUrl, callbackURLScheme: "\(urlScheme)://") { url, error in
            if let error = error {
                print(error)
            } else {
                if let url = url {
                    print(url)
                }
            }
        }

        authSession?.presentationContextProvider = self
        authSession?.start()
    }
    
}