Re: [Geoserver-users] How to offer a "download data" link through geoserver?

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Hi Andrea,

Darn, I should have done more research into WPS! Could have saved some time
I think.

gs:RectangularClip is probably just what I need, but running it out through
OGR2OGR would be the ticket.

As to WCS, there doesn't seem to be many examples of getting it to work
right, maybe I'll try again.

Thanks!
Roger

On Mon, Nov 1, 2010 at 5:30 PM, Andrea Aime <and...@ge...>wrote:

> On Mon, Nov 1, 2010 at 3:28 PM, Roger Bedell <syl...@gm...>
> wrote:
> > Hi Robert,
> > For our project, we did this in a variety of ways, finally settling on
> using
> > WFS with OGR for the vector data, and WMS for the raster. Unfortunately,
> to
> > get everything we wanted, we had to do some custom programming.
> >
> > The WFS with the OGR output works extremely well, with the exception that
> > vectors are not clipped at the boundaries of the requested feature, they
> > just keep going. Here is a sample of a WFS request of this type, note
> that
> > the output format is SHP, zipped, and projection is EPSG:2267.
> >
> > <wfs:GetFeature service="WFS" version="1.1.0" outputFormat="OGR-SHP-ZIP"
> > xmlns:ogi="http://204.62.18.181:8080/ogi"
> > xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> > xsi:schemaLocation="http://www.opengis.net/wfs
> >  http://schemas.opengis.net/wfs/1.1.0/wfs.xsd"
> > xmlns:ogc="http://www.opengis.net/ogc"
> > xmlns:wfs="http://www.opengis.net/wfs"
> > xmlns:gml="http://www.opengis.net/gml">
> >  <wfs:Query typeName="ogi:sections"
> srsName="urn:x-ogc:def:crs:EPSG:2267">
> >    <ogc:Filter>
> >      <ogc:Intersects>
> >        <ogc:PropertyName>the_geom</ogc:PropertyName>
> >        <gml:Polygon srsName="urn:x-ogc:def:crs:EPSG:4326"
> > xmlns:gml="http://www.opengis.net/gml">
> >          <gml:exterior>
> >            <gml:LinearRing>
> >              <gml:posList> 36.129833547944 -97.739353179937
> 36.129833547944
> > -97.620220184329 36.188044089569 -97.620220184329 36.188044089569
> > -97.739353179937 36.129833547944 -97.739353179937</gml:posList>
> >            </gml:LinearRing>
> >          </gml:exterior>
> >        </gml:Polygon>
> >      </ogc:Intersects>
> >    </ogc:Filter>
> >  </wfs:Query>
> > </wfs:GetFeature>
> >
> > I just got done adding a "clip to bounding polygon" output, but it is all
> > done using PostGIS, as this is not available in WFS, more custom
> > programming.
>
> Ah, this is clearly stepping out of WFS, WFS is a query service,
> cannot transform
> geometries.
> The good news is WPS can do rectangular clipping and it's pretty fast at it
> too.
> It does not have, however, an ogr2ogr output ability, thought with some
> (generic
> and reusable) programming it would be possible to get there.
>
> > As to Raster, I tried using WCS, but even when I got it to work it was
> very
> > slow, and I could never get the projection stuff to work. So, I went back
> to
> > WMS, being very careful with pixel size etc, then piping it out through
> GDAL
> > to get any projection output, more custom stuff!
>
> Pity. Slowness is probably due to WCS never using the overviews to get
> maximum
> accuracy. I think we changed that behavior lately and made it configurable,
> so
> on the 2.1.x series it should be possible to have a fast, even if less
> accurate, WCS.
> As for reprojection, hmmm... I guess there might be a bug at work.
> Would be nice to get a bug report with some sample requests and sample data
>
> Cheers
> Andrea
>
> -----------------------------------------------------
> Ing. Andrea Aime
> Senior Software Engineer
>
> GeoSolutions S.A.S.
> Via Poggio alle Viti 1187
> 55054  Massarosa (LU)
> Italy
>
> phone: +39 0584962313
> fax:     +39 0584962313
>
> http://www.geo-solutions.it
> http://geo-solutions.blogspot.com/
> http://www.linkedin.com/in/andreaaime
> http://twitter.com/geowolf
>
> -----------------------------------------------------
>