CODEWITHSUNDEEP
iosswiftxcode
Łukasz Betta
Łukasz Betta

Reputation: 161

Swift 4 - Invalid conversion from throwing function

I have connect.swift with code:

public struct Connect {
    let adresSerwera = "http://test.nazwa.pl/"
    typealias Odpowiedz = (Data?, Error?) -> Void


    func getJsonFromServer(parametry: String, wynikRequesta: @escaping Odpowiedz) {
        guard let Url = URL(string: self.adresSerwera + "kartyEndpoint.qbpage" + parametry) else { return }
        URLSession.shared.dataTask(with: Url) { (data, response, error) in
            if error == nil {
                guard let data = data else {
                    print("Error 100:  \(error)")
                    wynikRequesta(nil, error)
                    return
                }
                print("R>" + self.adresSerwera + "kartyEndpoint.qbpage?" + parametry)
                do {
                    //let json = try JSONDecoder().decode(forecast.self, from: data)
                    wynikRequesta(data, nil)
                    dump(data)
                    print("\(data)")

                } catch let err {
                    print("Error 101: ", err)
                    wynikRequesta(nil, err)
                }
            } else{
                print("Error 102: Problem with download data")
            }
        }.resume()
    }
    func sprawdzDaneLogowania(login: String?, haslo: String?, callback: @escaping Odpowiedz) {
        getJsonFromServer(parametry: "?action=LOGOWANIE&login=\(login!)&password=\(haslo!)", wynikRequesta: callback)
    }

}

and code to download data:

@IBAction func btnLoginPressed(_ sender: Any) {
        if self.textFieldLogin.text?.isEmpty ?? true || self.textFieldPassword.text?.isEmpty ?? true  {
            print("Uzupełnij wszystkie pola!!")
        } else {
            print("Pola uzupełnione")
            cms.sprawdzDaneLogowania(login: self.textFieldLogin.text, haslo: self.textFieldLogin.text, callback: { (data, blad) in
                if blad == nil{
                    if let dane = data {
                        let str = String(data: dane, encoding: .utf8)
                        let downloadedData = RankingGrupowyObject(JSONString: str!)


                        let decoder = JSONDecoder()
                        let zalogowanyUser = try decoder.decode(LoginUser.self, from: data)

                    } else {
                        print("Error 103: \(data)")
                    }
                } else {
                    print("Error 104: \(blad)")
                }


            })
        }
    }

for lines: cms.Check the Logs (login: self.textFieldLogin.text, password: self.textFieldLogin.text, callback: {(date, error) in

I get an error message:

Invalid conversion from throwing function of '(_, _) throws -> ()' is a non-throwing function type 'Connect. Answer' (aka '(Optional , Optional ) -> ()')

What have I done wrong? How can you fix this error? By using the CheckLogging function I would like to create a target object

Upvotes: 1

Views: 489

Answers (1)

EDUsta
EDUsta

Reputation: 1933

let zalogowanyUser = try decoder.decode(LoginUser.self, from: data)

This part is able to throw, meaning that you should either do/catch there:

do {
    let zalogowanyUser = try decoder.decode(LoginUser.self, from: data)
}
catch {
    print("Error in decoder")
}

Or let the error propagate onto upper parts. In order to do that, your method cms.sprawdzDaneLogowania could be marked as throws, or your that method's callback block could be marked as such.

Upvotes: 3

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