Add support for path custom type conversion

[SentryMan]

From the discord:

I'm thinking we could make it so that:

@Get("/something")
public void getMetadata(@QueryParam("id") Foo foo) {
  //
}

could generate something like:

    var id = asType(ctx.pathParam("id"), Foo::new);
    var result = controller.getMetadata(id);

Where asType would be a new method added that takes a reference to a constructor/valueOf method

[rbygrave]

Can we get more concrete examples of the types for this use case rather than Foo? I presume these are DDD types but let's get some good understanding of the motivation.

There is some interaction with the logic that determines what parameter is used for the body content. This is probably the main concern here - that we don't suffer in terms of handling the body parameter. This is somewhat because as avaje-http uses annotation processing we actually know the method parameter names and as such we then don't need explicit annotations for path parameters and query parameters ... and this then impacts the determination of which parameter is for the body.

Rightly or wrongly, we have the @BodyString annotation for the rare use case where the body is just a String. Calling that @BodyString instead of @Body almost feels like a mistake right at this moment.

[SentryMan]

This is probably the main concern here - that we don't suffer in terms of handling the body parameter.

this is simple to handle, this should only apply if it's a GET/DELETE HTTP verb, or if the parameter is explicitly annotated with @QueryParam/@Header/Other

[SentryMan]

Calling that @BodyString instead of @Body almost feels like a mistake right at this moment.

I'm indifferent, but since we're jumping major versions to 3.0 you have the opportunity to change it.

[rbygrave]

Can we get more concrete examples of the types for this use case rather than Foo? I presume these are DDD types but let's get some good understanding of the motivation.

We still need this. The description uses Foo which does not actually express the motivation.

In addition the discord example is not valid as it uses {foo} as a path parameter.

Ideally we get the description of this issue updated so that we clearly understand the motivation and use case.

Edit: My guess is that this is desired to support both query parameters and path parameters, it would be good to clarify exactly what this feature request is for.