Re: [PATCH 0/9] Multi-valued proposal (WIP)

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

On Wed, 2011-02-23 at 15:54 +0000, Iago Toral wrote:
> >>  I guess the question here is if the extra flexibility we get from 
> >> this
> >>  approach and the code reuse is worth the additional slight 
> >> obscurity.
> >>
> >>  The alternative to this, as I explained in an e-mail before would 
> >> be to
> >>  have explicit, fixed relations defined at compile time. Things 
> >> like:
> >>
> >>  GrlDataVideoURI, GrlDataThumbnail, etc
> >>
> >>  These would be structs:
> >>
> >>  typedef struct {
> >>    gchar *uri;
> >>    gchar *mime;
> >>    guint width;
> >>    guint height;
> >>    ...
> >>  } GrlVideoURI;
> >>
> >>  And then we would have API to set and get these structs from a 
> >> GrlData
> >>  object:
> >>
> >>  GrlMediaVideo *video;
> >>  GrlVideoUri *uri_data = grl_video_uri_new (uri, mime, width, 
> >> height);
> >>  grl_media_video_set_uri (video, uri_data);
> >>  ...
> >>  GrlVideoUri *uri_data = grl_media_video_get_uri (video);
> >>  gchar *uri = grl_video_uri_get_uri (uri_data);
> >>  gchar *mime = grl_video_uri_get_mime (uri_data);
> >>  ...
> >>
> >>  As you can see, the correlations here are fixed, they are defined 
> >> by
> >>  structures, so they are explicit and we provide the users with 
> >> specific
> >>  APIs to handle each correlation,, which I think is less obscure 
> >> than
> >>  using a generic API. The drawback is of course that they are
> fixed, 
> >> and
> >>  that you have to create structures and specific API for each 
> >> correlation
> >>  (more code) and you cannot define new relations at run-time.
> >
> > Exactly. If Grilo wouldn't allow to create new keys by plugins,
> then 
> > of
> > course I go with this approach.
> >
> > But here there is an important point I would like to say: what I
> sent 
> > is
> > a preliminary work that focus on the core part for adding 
> > multi-valued
> > properties. Based on this work, we can add new api to ease some 
> > things,
> > as we added api in GrlMediaAudio to ease its handle using GrlData 
> > api.
> >
> > Thus, maybe we can add your api proposal to GrlMediaVideo using
> > GrlDataMulti api to implement it.
> 
>  And how would you do that exactly?
> 

Basically, grl_media_video_set_uri(video, uri_data) can build a
GrlProperty with the content of uri_data and add it to
GRL_DATA_MULTI(video)


In the same way, grl_media_video_get_uri (video, 0) internally would get
the GrlProperty for position 0, and dump the values to the GrlVideoUri
structure.


If a plugin defines a new key that are correlated with the uri key,
basically means that using the GrlVideoUri you will lost the value,
because it won't be dumped to/from the structure. But still you have a
chance to get it.

	J.A.