Passing data to another view using a model - SwiftUI - swift

Question

I'm trying to pass the data retrieved from the API to a View, but I'm getting the following error:
Class 'ApiManagerViewModel' has no initializers
This is how the ViewModel looks:
class ApiManagerViewModel: ObservableObject {
#Published var blockchainData: ApiDataClass
func callAPI() {
guard let url = URL(string: "myapiurl") else {
print("Invalid URL")
return
}
let request = URLRequest(url: url, timeoutInterval: Double.infinity)
let callAPI = URLSession.shared.dataTask(with: request) { data, responce, error in
do {
if let data = data {
let decodedResponse = try JSONDecoder().decode(APIResponce.self, from: data)
DispatchQueue.main.async {
// update our UI
self.blockchainData = (decodedResponse.data)
}
// Everything is good, so we can exit
return
}
} catch {
print("Unexpected error while fetchign API: \(error).")
return
}
}
callAPI.resume()
}
This is the model:
// MARK: - APIResponce
struct APIResponce: Codable {
let data: ApiDataClass
let error: Bool
}
// MARK: - DataClass
struct ApiDataClass: Codable {
let address, quote_currency: String
let chain_id: Int
let items: [ApiItems]
}
// MARK: - Item
struct ApiItems: Codable {
let contract_decimals: Int32
let contract_name, contract_ticker_symbol, contract_address, logo_url, type, balance: String
let supports_erc: [String]?
let quote_rate: Double?
let quote: Double
}
I've tried initializing it but it's no bueno:
init() {
let address = 0, quote_currency = 0
let chain_id = 0
let items: [ApiItems]
}
If I initialize it like that I get the error, and I also don't want to repeat the same thing the model has:
Return from initializer without initializing all stored properties
I also tried with the variable like:
#Published var blockchainData = []
and I get the error on this line: self.blockchainData = (decodedResponse.data):
Cannot assign value of type 'ApiDataClass' to type '[Any]'
How can I make the variable blockchainData have the value coming from decodedResponse.data so I can pass it to another view?
Thanks

Answer 1

You're getting that error because you've declared var blockchainData: ApiDataClass, but haven't given it an initial value (your attempt at providing an initializer for ApiDataClass didn't help because the problem is ApiManagerViewModel).
The easiest solution to this is to turn it into an optional:
#Published var blockchainData: ApiDataClass?
Then, in your View, you'll probably want to check if it's available. Something like:
if let blockchainData = viewModel.blockchainData {
//code that depends on blockchainData
}
(assuming your instance of ApiManagerViewModel is called viewModel)