Settings.swift

//function that presents STPPaymentMethodsViewController
  func handlePaymentMethodsButtonTapped() {
        // Setup customer context
        let customerKeyProvider = StripeCustomerSessionManager()
        let customerContext = STPCustomerContext(keyProvider: customerKeyProvider)
        
        // Setup payment methods view controller
        let paymentMethodsViewController = STPPaymentMethodsViewController(configuration: STPPaymentConfiguration.shared(), theme: STPTheme.default(), customerContext: customerContext, delegate: self)
        
        // Present payment methods view controller
        let navigationController = UINavigationController(rootViewController: paymentMethodsViewController)
        present(navigationController, animated: true) //crashes here - doesn't crash when i comment out this line but then obviously doesn't present the vc either
        
  }

//delegate functions - not sure if necessary here
  func paymentMethodsViewController(_ paymentMethodsViewController: STPPaymentMethodsViewController, didFailToLoadWithError error: Error) {
        // Dismiss payment methods view controller
        dismiss(animated: true)
        
        // Present error to user...
    }
    
    func paymentMethodsViewControllerDidCancel(_ paymentMethodsViewController: STPPaymentMethodsViewController) {
        // Dismiss payment methods view controller
        dismiss(animated: true)
    }
    
    func paymentMethodsViewControllerDidFinish(_ paymentMethodsViewController: STPPaymentMethodsViewController) {
        // Dismiss payment methods view controller
        dismiss(animated: true)
        
        SwiftSpinner.show("Updating Payment Methods")
        APIManager.getWallet(success: { (w) in
            SwiftSpinner.hide()
            print("current wallet = ")
            print(w)
            print(w.defaultCard?.brandName)
            
            self.wallet = w
            self.tableView.reloadData()
            
        }, error: { (errorMessage) in
            // Handle error.
            SwiftSpinner.hide()
            
            let alertView = UIAlertController(title: "Error Fetching Payment Details", message: errorMessage, preferredStyle: .alert)
            alertView.addAction(UIAlertAction(title: "Dismiss", style: .default, handler: nil))
            self.present(alertView, animated: true, completion: nil)
            

            
        }, forceRefresh: true)
        
        
    }
    
    func paymentMethodsViewController(_ paymentMethodsViewController: STPPaymentMethodsViewController, didSelect paymentMethod: STPPaymentMethod) {
        // Save selected payment meth
        
        
    }