advanced-auth 2.md

Advanced User Authentication

In order for the iOS SDK to control the Spotify app, they will need to authorize your app. The functionality to do this is built in and can be implemented directly inside of your AppDelegate.swift:

Implement Session Delegate

In order to handle auth, we need to add a SPTSessionManagerDelegate inside of your AppDelegate.swift:

class AppDelegate: UIResponder, UIApplicationDelegate, SPTSessionManagerDelegate {
  ...

This will require us to implement the following three methods:

func sessionManager(manager: SPTSessionManager, didInitiate session: SPTSession) {
  print("success", session)
}
func sessionManager(manager: SPTSessionManager, didFailWith error: Error) {
  print("fail", error)
}
func sessionManager(manager: SPTSessionManager, didRenew session: SPTSession) {
  print("renewed", session)
}

Instantiate SPTConfiguration

At a class-level, we can define our Client ID, Redirect URI and instantiate the SDK:

let SpotifyClientID = "[your spotify client id here]"
let SpotifyRedirectURL = URL(string: "spotify-ios-quick-start://spotify-login-callback")!

lazy var configuration = SPTConfiguration(
  clientID: SpotifyClientID,
  redirectURL: SpotifyRedirectURL
)

Setup Token Swap

The authentication process provides a refresh_token, which can be stored locally inside of your app. This can be used, along with your Client ID, Client Secret and Redirect URL, to obtain an access_token that is valid for 60 minutes.

However, as we strongly discourage the use of Client Secrets in your iOS app code, we have written two well-documented web server examples that can do this for you:

• Glitch
• One-click deploy with Heroku

Once you have set them up, and have the tokenSwapURL and tokenRefreshURL we can set this up in our AppDelegate.swift in a class-level closure:

lazy var sessionManager: SPTSessionManager = {
  if let tokenSwapURL = URL(string: "https://[my token swap app domain]/api/token"),
     let tokenRefreshURL = URL(string: "https://[my token swap app domain]/api/refresh_token") {
    self.configuration.tokenSwapURL = tokenSwapURL
    self.configuration.tokenRefreshURL = tokenRefreshURL
    self.configuration.playURI = ""
  }
  let manager = SPTSessionManager(configuration: self.configuration, delegate: self)
  return manager
}()

Configure Initial Music

iOS requires us to define a playURI (as shown in the last step) in order to play music to wake up the Spotify main application. This is an iOS-specific requirement. There's two values self.configuration.playURI accepts:

An empty value: If empty, it will resume playback of user's last track. Example:

self.configuration.playURI = ""

A valid Spotify URI: Otherwise, provide a Spotify URI. Example:

self.configuration.playURI = "spotify:track:20I6sIOMTCkB6w7ryavxtO"

Invoke Auth Modal

With SPTConfiguration and SPTSessionManager both configured, we can invoke the authorization screen:

let requestedScopes: SPTScope = [.appRemoteControl]
self.sessionManager.initiateSession(with: requestedScopes, options: .default)

Configure Auth Callback

Once a user successfully returns to your application, we'll need to notify sessionManager about it by implementing the following method:

func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {
  self.sessionManager.application(app, open: url, options: options)
  return true
}

Now, when a user authorizes they should return to your application with the sessionManager(manager: SPTSessionManager, didInitiate session: SPTSession) method being successfully invoked.