Flutter create own class

Question

I am trying to create a class with methods inside to a specific Authentication process

So I have created a file MyAuthMethods.dart

class UserAuth {

  static int seconds = 10000000;
  static String username;
  static String password;
  static String key = "abc123";

  static Future<String> _generateAuthCode(seconds, username, password, key) async{
    var result = "something";
    print("Seconds: seconds, Username: username, Password: password, Key: key");

    return result;
  }

}

on my form (FormScreen.dart), a button has onPressed to execute the function

onPressed:(){
  UserAuth._generateAuthCode(UserAuth.seconds, "username", "password", UserAuth.key);
}

but it does not work. It says:

error: The method '_generateAuthCode' isn't defined for the class 'UserAuth'.

What do I need to change?

Answer 1

There are no keywords like public, protected and private in Dart. In order to make a variable or function private to a class, the name of the variable or function needs to start with underscore(_). Variables/function without underscore(_) are public. You have defined a private function and accessing the private function. You can fix by making the function public: in order to do so just remove the underscore from the function, make it generateAuthCode.

class UserAuth {

  static int seconds = 10000000;
  static String username;
  static String password;
  static String key = "abc123";

  static Future<String> generateAuthCode(seconds, username, password, key) async{
    var result = "something";
    print("Seconds: seconds, Username: username, Password: password, Key: key");

    return result;
  }

}

Answer 2

Unlike Java, Dart doesn’t have the keywords public, protected, and private. If an identifier starts with an underscore (_), it’s private to its library.

Libraries and visibility

So _generateAuthCode is the private method for your class , so that only you are not allowed to access.