Re: [Tracker] [Announce] Tracker 0.5.3

[Jamie McCracken <jamiemcc blueyonder co uk>]

Mikkel Kamstrup Erlandsen wrote:
> 2006/12/24, Jamie McCracken <jamiemcc blueyonder co uk 
> <mailto:jamiemcc blueyonder co uk>>:
>
>     Edward Duffy wrote:
>      > Congrats on getting another release out the door (and so close to
>      > Christmas)!
>      >
>      > On 12/23/06, Jamie McCracken <jamiemcc blueyonder co uk
>     <mailto:jamiemcc blueyonder co uk>> wrote:
>      >> * New improved metadata engine now sports multiple values per
>     metadata
>      >> item and rdf style recursive metadata relationships
>      >
>      > How does this work?  I poked around tracker-extract,
>      > tracker-metadata.c, tackerd.c, and tracker-db.c and they are all
>     using
>      > a GHashTable to store metadata.  Nothing really jumped out as being
>      > all that different.
>      >
>      >
>
>     The main stuff will be "Email:SentTo", "Email:CC" etc which needs to
>     support multiple values.
>
>     The metadata extraction, which I will work on over XMAS, will need to
>     delimit multiple values with semicolons which will then be aplit up and
>     stored in separate rows in the DB. So yeah they will need modifying
>     slightly.
>
>
>
> Does this mean that ;s will have to be escaped in the return values?

yes - ';' is not common in metadata?

email addresses are delimited by semi-colons as well in mboxes so no 
loss there :)

if semicolons are not good then we would need some other delimiter to 
use for the string in the GHashTable or we could use a GSList instead of 
a string but that would be more work...

>  
>
>     The changes that I have made are to the DB structure, metadata names,
>     metadata properties and the search mechanisms (rdf query and keywords).
>
>       I have also changed keywords to use the new metadata db directly and
>     the auto tagging is no longer needed as "Doc:Keywords" and
>     "Image:Keywords" are now children of type "DC:Keywords" so any search
>     for a keyword (either directly or in rdf query) will automatically
>     search DC:Keywords and all its children. (its open ended so more types
>     can be declared as a child of DC:Keywords and get searched automatically
>     too).
>
>
>
> This sounds really cool. One of my friends inquired me asking me if I 
> knew about  any tool that could do hierarchial  tags.  Fx. consider the 
> following tag hierarchy:
>
> hacking
> |--search
>    |--desktop-desktop
> |--gnome
>
> if i tag the file tracker.c with "desktop-search" and search my tags for 
> "hacking", tracker.c will show up in the results...

its the metadata type that is hierarchical not the actual tags so it 
would not work like that.

in trackers case a search on Image:Keywords would search all tags in 
Image:Keywords only

But a search on DC:Keywords would search all tags in DC:Keywords, 
Doc:Keywords and Image:Keywords (and any other metadata type which has 
DC:Keywords as a parent)




--
Mr Jamie McCracken
http://jamiemcc.livejournal.com/