Generic parameter with predefined method signature

Question

I have a HTTP client helper to make post request to an API:

 public static T post(U request, string URL)
        {
            HttpClient httpClient = new HttpClient();

            var responseContent = httpClient.PostAsync(
                    URL,
                    new StringContent(
                            JsonSerializer.Serialize<U>(
                                request,
                                Config.QrAuthJsonConfig.options
                            ),
                            System.Text.Encoding.UTF8,
                            "Application/Json"
                    )
             ).Result;

            var response = responseContent.Content.ReadAsStringAsync().Result;

            return JsonSerializer.Deserialize<T>(response);
        }

As you can note, URL is a second param. I would like a way U request can have a method signature to get the URL value from U request instance.

For example:

request.getUrl();

Thank you.

Answer 1

The (“post”) method with a “generic parameter with a predefined method” could use an interface or a (base) class.

1. Using an interface:

public static TSerialization Post<TSerialization, TRequest>(TRequest request) where TRequest : IUrlInfo
{
   //…
}

Define an interface

public interface IUrlInfo
{
    string Url { get; set; }
}

that you implement for each request

public class SomeRequest : IUrlInfo
{
    public string Url { get; set; } = “default-value-is-not-needed.com”;

    // other properties
}

2. Using an abstract class:

public static TSerialization Post<TSerialization, TRequest>(TRequest request) where TRequest : RequestBase
{
   //…
}

Define an abstract class

public abstract class RequestBase
{
    public string Url { get; set; }
}

that you implement for each request

public class SomeRequest : RequestBase
{
   // other properties
}