Comment 6 for bug 1492252

@Brian: Right. That could work under the following assumptions:
- the result uri uniquely identifies a result (currently we don't really require that nor make any assumptions around that anywhere in the shell as far as I remember) in the scope which is interested in providing that functionality;
- given a result uri, the scope can produce a *single* result in response;
- that would require a new method in the scopes API ("result_for_uri", "search_by_uri" or some such) to be implemented by scope author to provide this new functionality.
- the shell would need to do 2 calls (get the result by uri first, pass it to preview).
- alternatively, implement this with a new method such as "preview_by_uri", but I think I'm leaning towards the former approach with result_for_uri as building the previews is (usually) more complex part of the scope, so requiring scope authors to think of yet another entry point for previews is probably too much.