Re: [thredds] inconsistent catalog hierarchy with catalogRef

I still think this could be made to be consistent. Using getDatasets() on the catalogRef, the List that I get always has length one. It is either a "proxy" for the catalog (when it contains multiple top level datasets) or the top level dataset (when the catalog contains only one).

It seems to me that the former case should return a List of the top level datasets instead of adding a node to the DAG for the catalog itself. Or, always include the catalog as a node regardless of how many datasets it contains.

Thanks,
Doug

On 10/7/11 2:47 PM, Ethan Davis wrote:
Hi Doug,

I'm not surprised you are seeing that behavior with getProxyDataset().
Since a catalogRef is a substitute for a dataset (in both the XML and
the thredds.catalog classes), the reference must in some sense resolve
to a dataset. Unfortunately, a catalog is not a substitute for a dataset
nor is the mapping to a dataset always straight foward (e.g., a catalog
is not required to have a 'name' attribute, nor is it required to
contain a single, top-level dataset). So, I think what you are seeing is
the workaround we came up with to deal with this not always clear situation.

Given all that, it doesn't necessarily fall out that getDatasets() would
display the same behavior as getProxyDataset(). Though I also don't
think it is completely clear that it shouldn't.

Does that clarify why catalogRefs behave the way they do?  And, if so,
can you make this model work for what you're trying to do?

Ethan

On 10/5/2011 9:31 AM, Doug Lindholm wrote:
I am trying work with a catalog as a DAG of datasets. When I get the
children of a catalogRef node, I get different behavior depending on how
many datasets are in the referenced catalog. If there is only one
dataset, then it is returned as the sole member of the List. If the
catalog has more than one dataset, I get the catalog itself alone as a
dataset in the List. Using getProxyDataset() has the same problem.

Is this a "feature"? Between this, and my inability to use "name" or
"alias" (earlier email), the API is making it hard to do what I want
with the catalogs.

Thanks,
Doug

P.S. I'm using a recent 4.2 release of NetCDF-Java.

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