Bastian Schäffer ha scritto: > List, > > during the latest OGC OWS-7 testbed, we encountered some issues with the > GML3 srsName encoding: > > A generated FeatureCollection, where the featureType's SRS is correctly > set to a representation of EPSG:4326, the result looks like: > > <gml:Envelope srsName="http://www.opengis.net/gml/srs/epsg.xml#4326";> > > By looking at the OGC practice as defined in the OGC policy directives, > in particular > > http://portal.opengeospatial.org/files/?artifact_id=37802 > > the correct URI would be urn:ogc:def:crs:EPSG::4326. > The equivalently correct URL would be > http://www.opengis.net/def/crs/EPSG/0/4326. > > This differes from http://www.opengis.net/gml/srs/epsg.xml#4326 > > Is it possible to set the value for srsName manually? Or fix the code > for future version?
I would strongly recommend against that if you keep on generating GML2. The EPSG:4326 vs http://www.opengis.net/gml/srs/epsg.xml#4326 vs urn:ogc:def:crs:EPSG::4326 is not only a matter of giving a name, it's also a matter of: - GML version used - axis order The urn notation was released at the same time as GML3 and WFS 1.1, so I would recommend that you switch to GML3 encoding if you want to use the urn notation, a GML2 parser won't be likely to recognize the new notation. The second issue is that when relasing the first two notation the axis order was not well specified and everybody went lon/lat, but when releasing the urn:ogc:def:crs:EPSG::4326 notation OGC stated that you have to use the "auhority axis order" which in the case of EPSG means lat/lon for most (all?) geographic coordinate systems. Compare this WFS 1.0 output: http://demo.opengeo.org/geoserver/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=tiger:poi&maxFeatures=1 with the compliant WFS 1.1 one: http://demo.opengeo.org/geoserver/ows?service=WFS&version=1.1.0&request=GetFeature&typeName=tiger:poi&maxFeatures=1 (I know it seems odd, I had quite a long and sorry discussion with OGC representatives about that and they were adamant that is the correct behavior) The second uses the urn notation recommended at the time WFS 1.1 was written (urn:x-ogc:def:crs:EPSG:4326) and _flips_ the coordinates. A capable GML3 parser should be able to handle that, but I fear not many really can. I believe that when we'll start encoding GML 3.2 we'll also have to switch to the "newer" urn:ogc:def:crs:EPSG::4326 notation (a WFS 1.1 client following the spec is not guaranteed to be able to parse it due to the minor changes OGC made in it). > > P.S. > During the last OGC TC meeting held this week, it was decided that the > OGC will mainly use URLs instead of URIs as identifiers. Hummm... odd? urn:x-ogc:def:crs:EPSG:4326 is a URI but not a URL afaik Cheers Andrea -- Andrea Aime OpenGeo - http://opengeo.org Expert service straight from the developers. ------------------------------------------------------------------------------ ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo _______________________________________________ Geotools-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-devel
