Getting started with the iOS SDK

curl https://api.stripe.com/v1/terminal/connection_tokens \
  -u 
sk_test_4eC39HqLyjWDarjtT1zdp7dc
: \
  -X "POST"

post '/connection_token' do
  token = # ... Create or retrieve the ConnectionToken
  {secret: token.secret}.to_json
end

import StripeTerminal

// Example API client class for communicating with your backend
class APIClient: ConnectionTokenProvider {

    // For simplicity, this example class is a singleton
    static let shared = APIClient()

    // Fetches a ConnectionToken from your backend
    func fetchConnectionToken(_ completion: @escaping ConnectionTokenCompletionBlock) {
        let config = URLSessionConfiguration.default
        let session = URLSession(configuration: config)
        guard let url = URL(string: "https://{YOUR BACKEND URL}/connection_token") else {
            fatalError("Invalid backend URL")
        }
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        let task = session.dataTask(with: request) { (data, response, error) in
            if let data = data {
                do {
                    // Warning: casting using `as? [String: String]` looks simpler, but isn't safe:
                    let json = try JSONSerialization.jsonObject(with: data, options: []) as? [String: Any]
                    if let secret = json?["secret"] as? String {
                        completion(secret, nil)
                    }
                    else {
                        let error = NSError(domain: "com.stripe-terminal-ios.example",
                                            code: 2000,
                                            userInfo: [NSLocalizedDescriptionKey: "Missing `secret` in ConnectionToken JSON response"])
                        completion(nil, error)
                    }
                }
                catch {
                    completion(nil, error)
                }
            }
            else {
                let error = NSError(domain: "com.stripe-terminal-ios.example",
                                    code: 1000,
                                    userInfo: [NSLocalizedDescriptionKey: "No data in response from ConnectionToken endpoint"])
                completion(nil, error)
            }
        }
        task.resume()
    }
}

import UIKit
import StripeTerminal

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
        Terminal.setTokenProvider(APIClient.shared)
        // ...
        return true
    }

    // ...

}

import UIKit
import StripeTerminal

class ReaderDiscoveryViewController: UIViewController, DiscoveryDelegate {

    var discoverCancelable: Cancelable?

    // ...

    // Action for a "Discover Readers" button
    func discoverReadersAction() {
        let config = DiscoveryConfiguration(
          discoveryMethod: .bluetoothScan,
          simulated: true
        )

        self.discoverCancelable = Terminal.shared.discoverReaders(config, delegate: self) { error in
            if let error = error {
                print("discoverReaders failed: \(error)")
            } else {
                print("discoverReaders succeeded")
            }
        })
    }

    // ...

    // MARK: DiscoveryDelegate

    // This delegate method can get called multiple times throughout the discovery process.
    // You might want to update a UITableView and display all available readers.
    // Here, we're automatically connecting to the first reader we discover.
    func terminal(_ terminal: Terminal, didUpdateDiscoveredReaders readers: [Reader]) {

        // Select the first reader we discover
        guard let selectedReader = readers.first else { return }

        // Only connect if we aren't currently connected.
        guard terminal.connectionStatus == .notConnected else { return }

        Terminal.shared.connectReader(selectedReader) { reader, error in
            if let reader = reader {
                print("Successfully connected to reader: \(reader)")
            } else if let error = error {
                print("connectReader failed: \(error)")
            }
        })
    }
}