web bindings

[cpurdy]

Extending on from JK's sock shop port to Ecstasy ...

    @Get("/{id}")
    @Produces("application/json")
    conditional Cart getCart(@PathParam("id") String id)

Because the id is specified in the URI template, and because JSON is our default media type, we will be able to do:

    @Get("/{id}")
    conditional Cart getCart(String id)

... or even:

    @Get("/{id}")
    conditional Cart getCart(Int id)

(In the latter case, there is some question as to how to report the error if the value is not an integer.)

Similarly, the Session and Request objects are always assumed to be available, so if JK had needed them within the method, the method could simply have those as params:

    @Get("/{id}")
    conditional Cart getCart(Int id, Session session, Request req)

They're also available as properties on the web service containing the method (but the properties are of the nullable Session? and Request? types, so the code wouldn't be quite as clean.)