Cannot receive results from Square Point of Sale in a small Swift app - swift

Question

I have written a small app in Swift using Xcode 12.5 by following the information and code samples provided here ... https://github.com/square/SquarePointOfSaleSDK-iOS
The app polls a server to see if there is a charge to be made. The output from the server is in JSON format. When a charge comes in, the JSON results are providing a customer id, amount to be charged, and a note to the Square Point of Sale SDK.
Using the SCCAPIRequest example from the GitHub page ...
// Replace with your app's URL scheme.
let callbackURL = URL(string: "<#T##Your URL Scheme##String#>://")!
// Your client ID is the same as your Square Application ID.
// Note: You only need to set your client ID once, before creating your first request.
SCCAPIRequest.setApplicationID(<#T##Application ID##String#>)
do {
// Specify the amount of money to charge.
let money = try SCCMoney(amountCents: 100, currencyCode: "USD")
// Create the request.
let apiRequest =
try SCCAPIRequest(
callbackURL: callbackURL,
amount: money,
userInfoString: nil,
locationID: nil,
notes: "Coffee",
customerID: nil,
supportedTenderTypes: .all,
clearsDefaultFees: false,
returnsAutomaticallyAfterPayment: false,
disablesKeyedInCardEntry: false,
skipsReceipt: false
)
// Open Point of Sale to complete the payment.
try SCCAPIConnection.perform(apiRequest)
} catch let error as NSError {
print(error.localizedDescription)
}
The app successfully switches to Square POS, displays the amount due, and knows which customer I am wanting to charge (via customer id). I can process the payment and Square POS switches back to my app just fine.
This is where I am running in to trouble. I am also using the UIApplication delegate method example on that same page. Under the comment "Handle a successful request" ...
func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {
guard SCCAPIResponse.isSquareResponse(url) else {
return
}
do {
let response = try SCCAPIResponse(responseURL: url)
if let error = response.error {
// Handle a failed request.
print(error.localizedDescription)
} else {
// Handle a successful request.
}
} catch let error as NSError {
// Handle unexpected errors.
print(error.localizedDescription)
}
return true
}
I have added the following ...
print("Transaction successful: \(response)")
From what I understand, the response should include the transaction id, and anything that was passed along in the userInfoString. It appears that this code example isn't even firing when Square POS returns to my app. I cannot see anything in the Xcode console.
I have assigned a callback URL within Xcode using the documentation on the link above, and it's also added in the Square Developer Portal under the Point of Sale API.
What am I missing? Where should the UIApplication delegate method be placed, in AppDelegate.swift or should it reside in ViewController.swift, or somewhere else? Any insight would be greatly appreciated.

Answer 1

#ElTomato provided me with the hint that I needed to solve the problem I was having. I needed to delete SceneDelegate.swift, remove Application Scene Manifest from Info.plist, and remove some code from AppDelegate.swift
I found detailed instructions on THIS site ...
iOS 13: Swift - 'Set application root view controller programmatically' does not work
Thank you kindly for the fantastic help #ElTomato