> -----Original Message-----
> From: 
> [EMAIL PROTECTED] 
> [mailto:[EMAIL PROTECTED]
> al.org] On Behalf Of Joshua Lieberman
> Sent: 06 September, 2007 12:09 PM
> To: Raj Singh
> Cc: [EMAIL PROTECTED]; 
> [email protected]
> Subject: Re: [Context.RWG] Associating WMS and WFS in the same layer
> 
> It would be best, I think, to point link a WMS layer with a 
> WFS layer, so that they can have separate information. The 
> DataURL element in ResourceType is another way to point at 
> the right WFS for the features in a WMS layer. It is a bit 
> inferential in that you would presumably supply the 
> GetFeature request with only the featureType specified in the 
> DataURL and the client would need to infer how to create its 
> own request with the appropriate filter, possibly as a POST 
> instead of a GET.
> 

True.  We do this for our Capabilities documents where applicable, i.e.
put a GetFeature request in DataURL, which would return the entire
dataset.

> The DescribeLayer request does not necessarily supply any 
> clear WFS binding information except for the endpoint which 
> "could" differ from that of the GetFeature request.
> 

As well as Query/@typeName, which "could" differ also.  Could one not
cobble together a GetFeature from this? i.e.:

- read OWC
- foreach ResourceList/Layer
 - do a DescribeLayer request
 - if WFS-able
 - set URL, typename somewhere in app, expose as "extractable"
 - when the user wants to extract, client binds and spatial and / or
aspatial criteria together in a Filter construct and passes along

The only thing that won't be around is the WFS version, which could be
figured out by some version negotiation either after a successful
DescribeLayer request or before a GetFeature request.

> Perhaps the group attribute would be useful here, to group a 
> corresponding WMS and WFS resource together. We never defined 
> particular vocabulary or syntax for this element, but the 
> idea was to support various larger layer structures including nesting.
> 

This is true.  But what happens if you want to group a bunch of
extratable layers together?  Would we need nested grouping?

> --Josh
> 
> On Sep 6, 2007, at 10:27 AM, Raj Singh wrote:
> 
> > I agree with Tom. The idea of joining the 2 services so 
> explicitly in 
> > the Context encoding is also limiting or misleading in a 
> way, because 
> > there are scenarios where the "navigation" WMS doesn't need to be 
> > showing the same data as the "download" WFS.
> >
> > If the interest is in a general way to signal that two or more 
> > services only make sense when used together, maybe a better 
> idea is to 
> > allow nested <ResourceList>s, and give that element some metadata, 
> > like a title and abstract.
> >
> > ---
> > Raj
> >
> >
> > On Sep 6, 2007, at 8:24 AM, Kralidis,Tom [Burlington] wrote:
> >
> >>
> >>
> >>> -----Original Message-----
> >>> From: Cameron Shorter [mailto:[EMAIL PROTECTED]
> >>> Sent: 05 September, 2007 4:41 PM
> >>> To: [EMAIL PROTECTED];
> >>> '[email protected]'; Kralidis,Tom 
> [Burlington]
> >>> Subject: Associating WMS and WFS in the same layer
> >>>
> >>> Tom,
> >>> Another OWS Context question.
> >>> In the CGDI Pilot we are working on, there is a 
> requirement to find 
> >>> and then download GML from a WFS.
> >>>
> >>> When finding a dataset, a user will generally want to use WMS 
> >>> interface to view datasets because it requires less 
> bandwidth. Then 
> >>> when the Area Of Interest has been selected, the user 
> will download 
> >>> the dataset using WFS.
> >>>
> >>> In order to do this, we need to associate a WMS layer with a WFS 
> >>> layer.
> >>> I think this should be done using something like:
> >>>
> >>>    <Layer queryable="0" hidden="0">
> >>>      <Server service="OGC:WMS" version="1.0.0"
> >>> title="OGC:WMS" default="1">
> >>>        <OnlineResource xlink:type="simple"
> >>> xlink:href="http://localhost:8080/wms"/>
> >>>      </Server>
> >>>      <Server service="OGC:WFS" version="1.0.0" title="OGC:WFS">
> >>>        <OnlineResource xlink:type="simple"
> >>> xlink:href="http://localhost:8080/wms"/>
> >>>      </Server>
> >>>      <Name>basic</Name>
> >>>      <Title>World Basemap</Title>
> >>>      <SRS>EPSG:4326</SRS>
> >>>    </Layer>
> >>>
> >>>
> >>> Note, this means that a WFS layer should be inserted inside a 
> >>> <Layer> tag instead of a <FeatureType> tag.
> >>> This comment could be extended to showing the same layer as KML, 
> >>> Tiled WMS, ...
> >>>
> >>> Tom, what are your thoughts on this?
> >>>
> >>
> >> Isn't this what WMS DescribeLayer is for?  What I would do 
> is a WMS 
> >> DescribeLayer request, which would tell you if a layer if 
> WFS-able or 
> >> not; if it is, then mark as extractable in your client and chain 
> >> along.
> >>
> >> Would this be feasible?
> >>
> >> ..Tom
> >>
> >> _______________________________________________
> >> Context.rwg mailing list
> >> [EMAIL PROTECTED]
> >> https://mail.opengeospatial.org/mailman/listinfo/context.rwg
> >
> > _______________________________________________
> > Context.rwg mailing list
> > [EMAIL PROTECTED]
> > https://mail.opengeospatial.org/mailman/listinfo/context.rwg
> 
> _______________________________________________
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> 

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