Routing system should introduce some abstraction for converting route parameters to strings.

[voroninp]

Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

I am working with typed ids:

public readonly record struct FooId(Guid Value);

If I use this value as a route parameter value and do not override ToString it is converted to string as FooId { Value = '....' }. That is obviously not what I want to have in a generated URL.

IMO, framework should not force my types to have a certain behavior. Writing parameter value to a URL is effectively a serialization, hence there should be the same level of flexibility/extensibility.

While framework offers outbound parameter transformers, they are not connected to the types of parameter values.

Describe the solution you'd like

I'd like ASP.NET to introduce a specific interface:

public interface IRouteParaemterValueStringConverter<TParameterValue>
{
    string Convert(TParameterValue value);
}

Its default implementation can just convert to string.

Additional context