[pycsw-devel] typeName in GetRecords requests

[Tom Kralidis]

Ryan/Steve: thanks for the info.  I've opened an issue at https://github.com/geopython/pycsw/issues/105.

> From: steve.richard at azgs.az.gov
> To: tomkralidis at hotmail.com; ryan.clark at azgs.az.gov; pycsw-devel at lists.osgeo.org
> Subject: RE: [pycsw-devel] typeName in GetRecords requests
> Date: Thu, 7 Feb 2013 18:59:24 -0700
> 
> csw:record is the only queryable type "In the case of XML realization of the
> OGC core metadata properties", but the pycsw capabilities document lists
> gmd:MD_Metadata and csw:record as valid values for the typeName parameter,
> and the queryable element section includes the ISO profile queryables.  
> 
> Even so, if csw:record is the only queryable type, then Ryan's query with
> typeName=gmd:MD_Metadata should fail, not the one with typeName=csw:Record.
> The typeName specifies the information model for the queryies (e.g. in an
> OGC:filter element, the xpaths are relative to the root element for the xml
> element specified by typeName).  The typeName you have in the pycsw table is
> the root element for the Metadata content. CSW and WFS both make a
> distinction between the query information model and the response information
> model.  Thus you could pose a query for dc:title="something" (with
> typeName=csw:record) and ask for outputSchema=gmd:MD_Metadata, or query for
> //gmd:title/gco:CharacterString="something" (with typename=gmd:MD_Metadata)
> and ask for outputSchema=csw:record.
> 
> I think there's a problem with the pycsw implementation in this respect...
> (see also page 46 in OGC 07-045)
>  
> But pycsw is still a very handy component! Glad it exists.
> 
> steve
> 
> > -----Original Message-----
> > From: Tom Kralidis [mailto:tomkralidis at hotmail.com]
> > Sent: Thursday, February 07, 2013 5:33 PM
> > To: Ryan Clark; pycsw-devel at lists.osgeo.org
> > Cc: Stephen Richard
> > Subject: RE: [pycsw-devel] typeName in GetRecords requests
> > 
> > ________________________________
> > > From: ryan.clark at azgs.az.gov
> > > Date: Thu, 7 Feb 2013 13:44:56 -0700
> > > To: pycsw-devel at lists.osgeo.org
> > > CC: steve.richard at azgs.az.gov
> > > Subject: [pycsw-devel] typeName in GetRecords requests
> > >
> > > Hi!
> > >
> > > I'm experimenting with pycsw. I set everything up and used the
> > > pycsw-admin.py function to import a set of XML records into my
> > > database. The files were ISO19139 docs. That was cool how easy it was.
> > >
> > 
> > Glad this worked for you.  Comments and suggestions are most welcome on
> > improving the backend admin interface, too.
> > 
> > > After the load, I tried some GetRecords requests. I noticed that
> > > requests in which I specify ...&typeNames=gmd:MD_Metadata... gives me
> > > the results I expect. However, if I specify typeNames=csw:Record I
> > > don't get any results.
> > >
> > 
> > When pycsw loads metadata into its repository, it stores the typename of
> the
> > metadata (csw:Record, gmd:MD_Metadata, etc.), and this value it what is
> uses
> > when responding to a GetRecords query with the typeNames parameter.
> > 
> > Section 10.8.4.8 of CSW 2.0.2 (07-006r1) says that csw:Record is the only
> > queryable entity (typename).  The ISO AP (07-045), as an example, allows
> for
> > typename 'gmd:MD_Metadata'.
> > 
> > > Does that seem like a bug, or a feature? To me it seems a little
> > > contradictory to the description of the typeNames parameter in the CSW
> > > spec. I think I've seen a similar issue in GeoNetwork in the past, but
> > > I ran similar queries using ESRI's Geoportal and I got the results I
> > > expected regardless of what I put as typeName.
> > >
> > 
> > That's a good question.  In pycsw it's by design, so clients that want to
> query all
> > typenames would fetch all the applicable typenames from a GetCapabilities
> > response and pass them (comma-separated) in the GetRecords request.
> > 
> > For me, I find this consistent with querying a WFS; each typename is a
> different
> > entity and querying a specific typename will return results based on that
> > typename only, which allows to filter metadata sets by typename, if you
> want.
> > 
> > Having said this, I may be interpreting this incorrectly, what do others
> think?  It
> > might be valuable also to clarify this with OGC (maybe in the public
> forum?).  If
> > pycsw handles things incorrectly, we will certainly fix this immediately. 
> If things
> > are still blurry, we could certainly put a flag (say pedantic=False) in
> pycsw's
> > config to allow the server to always query all typenames.
> > 
> > Thanks
> > 
> > ..Tom
> 
 		 	   		  
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