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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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