Re: CatalogRefs

Hi Carl,

John is on vacation but got a chance to forward this to me. Sending 
email to address@hidden works better as it will get to 
the person/people that are here.

As I recall, you're doing all these catalogs by hand. Is that right?

You can certainly include the metadata at the top catalogRef level. It 
is available in the XML even though it doesn't show up in the HTML view. 
There isn't really a way to have the metadata inherited across 
catalogRef links. The referring and referred catalogs are independent 
and so there is no inheritance of metadata between the two. The best you 
can do with hand generated catalogs is to duplicate the metadata in the 
various locations. Obviously, not such a great choice from the 
maintenance side of things.

On the other hand, the <datasetScan> based catalog generation used by 
the TDS does exactly this. You include metadata (inherited or not) at 
the datasetScan element and it is automatically included in all the 
catalogs generated by this datasetScan. (Well, the inherited metadata is 
included in all of them, the non-inherited is only included in the 
catalog generated for the top-level of the datasetScan.)

Hope this is helpful. Let us know if you have more questions.

Ethan

Carl Wolfteich wrote:
> Hi John,
> It was nice to finally meet you at the Data Discovery meeting.  I 
> learned a lot more out there about the  overall problem of making data 
> more "discoverable" for the user/researcher.  We are working here on 
> trying to devise and implement a search interface for the thredds 
> catalogs I am producing.  I do use CatRefs as a means of breaking up 
> larger catalogs.  In talking with Dan, it appears that a search 
> capability would be easier to construct if I was able to put the 
> important metadata at the CatRef level rather than at the 
> directory/granule level.
>
> For example, given the xml file that produces this:
>
> http://dodsdev.gso.uri.edu:8080/thredds/catalogServices?catalog=http://dodsdev.gso.uri.edu:8080/thredds/cataloggen/catalogs/sst1.xml 
>
>
> Right now, this xml file just consists of CatRef links to the 
> respective datasets.  The metadata is included in the xml files called 
> by these links.   I would like to move the metadata one step up and 
> have it included with the CatRef information.   Is there a way I can 
> incorporate metadata information into this xml file (e.g. sst1.xml).  
> I have tried including the same metadata information with the CatRefs 
> in sst1.xml, and it seems to have no problems or errors with it.  But 
> I am wondering, first, is this  searchable in the xml?, even though 
> there is no html expression for it?  Second, is there a way I can 
> include the metadata information at this level (sst1.xml) for each 
> CatRef call and have it inherited on down to the dataset it is 
> calling?  When I tried to add "inherited metadata" with the CatRef, it 
> was not passed down to the dataset when I linked to it.
>
> So instead of:  (e.g., sst1.xml presently)
> <catalog
> <catalogRef/>
> <catalogRef/>
> <catalogRef/>
> ...
> </catalog>
>
> I would like to have
>
> <catalog
> <catalogRef
> <metadata...
> ..
> </metadata>
> </catalogRef>
> <catalogRef
> <metadata...
> ...
> </metadata>
> </catalogRef>
> ...
> </catalog>
>
> Is there a way to do this such that the metadata is inherited by each 
> respective dataset being called?  When I tried this it was not passed 
> down, I still had to include metadata at the dataset level.  This may 
> be going against convention here but it appears if I can bring this 
> metadata one level up to the xml file calling the CatRefs it would 
> make it easier to implement a search protocol.  Is this doable?  
> Appreciate your thoughts.  Thanks.
> Carl

--
Ethan R. Davis                                Telephone: (303) 497-8155
Software Engineer                             Fax:       (303) 497-8690
UCAR Unidata Program Center                   E-mail:    address@hidden
P.O. Box 3000
Boulder, CO  80307-3000                       http://www.unidata.ucar.edu/
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