Strange JSON API response SWIFT - ios

Question

I am sending an HTTP POST request to an API in swift and it is supposed to respond with:
{
"results": [
{
"alternatives": [
{
"transcript": "how old is the Brooklyn Bridge",
"confidence": 0.98267895
}
]
}
]
}
However, I am receiving this through the print(jsonResponse) function:
Optional({
results = (
{
alternatives = (
{
confidence = "0.9688848";
transcript = "how old is the Brooklyn Bridge";
}
);
}
);
})
Is there any reason why the response is not arriving in the correct format as indicated in the API documentation? I need to Decode the response to obtain the "transcript" value. However, I am receiving the following error:
keyNotFound(CodingKeys(stringValue: "transcript", intValue: nil), Swift.DecodingError.Context(codingPath: [], debugDescription: "No value associated with key CodingKeys(stringValue: \"transcript\", intValue: nil) (\"transcript\").", underlyingError: nil))
Maybe my request isn't optimal... Here's my code, any help is appreciated!
let parameters = ["config": ["encoding": "FLAC", "sampleRateHertz": "16000", "languageCode": "en-AU"], "audio": ["uri":"gs://cloud-samples-tests/speech/brooklyn.flac"]]
guard let url = URL(string: "https://speech.googleapis.com/v1/speech:recognize?key=AIzaSyDqYpPQIabwF5L-WibBxtVsWRBrc8uKi4w") else {return}
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
do {
request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: []) // pass dictionary to nsdata object and set it as request body
} catch let error {
print(error.localizedDescription)
}
URLSession.shared.dataTask(with: request) { (data , response , error) in
guard let data = data else {return}
do {
let jsonResponse = (try? JSONSerialization.jsonObject(with: data, options: []))
print("\(jsonResponse)")
let course = try JSONDecoder().decode(Course.self , from : data)
print(course.transcript)
} catch {
print(error)
}
}.resume()
Here is my Course code block: Do I need to include the other components in the struct as well as the transcript?
struct Course: Decodable {
let transcript: String
enum CodingKeys: String, CodingKey {
case transcript = "transcript"
}
}

Answer 1

jsonResponse is an Optional Dictionary, and thus that's why it's debug description looks like what you printed rather than pure JSON as you were looking for. Your problem likely is that your Decodeable objects are not properly setup - as by the looks of it you only have one Course. You'll likely need two more Response which contains a list of Alternatives. And then in Alternative you have a list of Courses.
Structure your objects like this, and it should do the trick:
struct Response: Decodable {
let results: [Alternative]
}
struct Alternative: Decodable {
let alternatives: [Course]
}
struct Course: Decodable {
let transcript: String
let confidence: Float
}
And then swap this line:
let course = try JSONDecoder().decode(Course.self , from : data)
With this change:
let course = try JSONDecoder().decode(Response.self, from: data).results[0].alternatives[0]