Re: What about GrlMedia resolving?

["Juan A. Suarez Romero" <jasuarez igalia com>]

On Wed, 2014-11-12 at 22:15 +0100, Guilhem Bonnefille wrote:
> If someone can point me a good documentation on the role of the grilo
> resolve function... it will help me to decide if I have to provide
> such function in my plugin, or if I don't.

resolve() function is used to provide information about metadata keys
that weren't asked before in a browse/search operation.

For example, a client could request in a search operation about "title"
and "author". So source would be returning only that information.

If later the client wants to show a new field, like "thumbnail", for a
specific media, it would use resolve() and ask for "thumbnail".

Let's show a different but real example. You want to show in a grid the
results from searching all Videos in YouTube. Specifically, you want to
show a thumbnail and a title below.

So you ask Grilo for both fields, plus URL for further playing. But, in
order to be as faster as possible, you use the GRL_RESOLVE_FAST_ONLY
flag, which makes the Grilo to drop those fields that could make the
query too much slow.

In the case of YouTube, asking for URL makes the search/browse slow, so
Grilo will drop that key: the results you ask for only contain thumbnail
and title. No problem. You show the content, and user clicks on video to
play it. Well, you realize you don't have URL, so you use resolve() to
ask for URL in that case.


So in summary, if you don't provide resolve() it means the clients only
can get the required fields in the browse or search operations. They
can't ask later for the fields that weren't asked before.

        J.A.