Resolving URIs to handlers

[sazzer]

Hi there,

The existence of HttpRequest::url_for is fantastic for building real REST APIs. I can use this to generate URIs for other resources so that I can correctly generate the hypermedia graph.

However, what I can't quite work out how to do is the opposite. To take a URL that was was provided to me and convert it back into the details of what it resolves to.

If I understand it right, I can use HttpRequest::resource_map().match_name() to get the name of the handler that matches a given URL, but this doesn't give me the binds.

For example, if I had:

    config.service(
        web::resource("/users/{id}")
            .name("users_user_by_id")
            .route(web::get().to(get::handler)),
    );

Then I could use req.resource_map().match_name("http://localhost:8000/users/abc") to get Some("users_user_by_id"), but that would not tell me that the {id} bind was assigned the value "abc".

Is there any way to get this full expansion?

Cheers

[robjtede]

If you mean the path dynamic segments within the current handler, than use the Path extractor.

[sazzer]

Unless I'm missing something though, that's used to parse the current request. Not an arbitrary URI that might be passed to another request.

For example, in a hypermedia API I might make a request like: GET /posts?user=http://blog.example.com/users/abc - i.e. a call to /posts with a query parameter that is the URI to a user.

What this means is that the handler for web::resource("/posts").route(web::get().to(search::handler)) needs to be able to:

• Take the string http://blog.example.com/users/abc.
• Parse it as a URI.
• Get an indication that this URI matches the route users_user_by_id.
• Get the string "abc" as the value for the {id} bind.

That last bullet point is the one that I can't work out how to do.

[robjtede]

Ahh I see what you mean. Doesn't look like this is possible with current methods.

Tracking this feature here: #2571

[robjtede]

Not currently possible, feature is being tracked: #2571