[OpenLayers-Users] Consuming WFS Complex Features

[Andreas Hocevar]

Hi,

extending our versions XML parsers is the way to go, and it is easy. Don't
look at OpenLayers.Format.GML, but at OpenLayers.Format.GML.Base and the
version specific parsers. All you need to do is add readers to the readers
object literal (and writers if you also want to encode) for your schema
specific format.

Andreas.
On Nov 4, 2011 2:08 AM, "amacleod" <webmaster at cecc.com.au> wrote:

> Hi All
>      Just wondering if anyone has any experience in getting Openlayers to
> consume complex features from a WFS service.
>          From what I can tell from our struggles to get this working, the
> Openlayers GML parser is only designed for simple features. It has problems
> when there are mixed namespaces in the service and is unable to determine
>          the correct geometry element to use. Before we go and look at
> extending
> the GML parser, I thought I would see if there was any other work going on
> in this area. We are a bit new to this space so please forgive my
>          ignorance if we are missing something glaringly obvious or doing
> something incorectly. I've provided as much detail as I can below. Any
> assistance would be apreciated.
>
>          Sample WFS data (notice the mixture of gml: gsml: gwml: and sa:
> namespaces)
>
>          <wfs:FeatureCollection numberOfFeatures="10"
> timeStamp="2011-11-04T10:44:01.663+11:00"
> xsi:schemaLocation="http://www.opengis.net/wfs
> http://schemas.opengis.net/wfs/1.1.0/wfs.xsd
> http://www.nrcan.gc.ca/xml/gwml/1
> http://ngwd-bdnes.cits.nrcan.gc.ca/service/gwml/schemas/gwml.xsd"
> xmlns:wfs="http://www.opengis.net/wfs"
> xmlns:ogc="http://www.opengis.net/ogc"
> xmlns:gwml="http://www.nrcan.gc.ca/xml/gwml/1"
> xmlns:sa="http://www.opengis.net/sampling/1.0"
> xmlns:swe="http://www.opengis.net/swe/1.0.1"
> xmlns:om="http://www.opengis.net/om/1.0"
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> xmlns:gsml="urn:cgi:xmlns:CGI:GeoSciML:2.0"
> xmlns:ows="http://www.opengis.net/ows"
> xmlns:gml="http://www.opengis.net/gml" xmlns:test="http://test.org"
> xmlns:xlink="http://www.w3.org/1999/xlink">
>                <gml:featureMembers>
>                <gwml:WaterWell gml:id="ffsr.waterwell.-877519">
>                <gml:name
> codeSpace="http://www.ietf.org/rfc/rfc2616">
> http://groundwater.data.vic.gov.au/waterwell/ffsr/ffsr.waterwell.-877519
> </gml:name>
>                <sa:sampledFeature
> xlink:href="http://www.opengis.net/def/nil/OGC/0/unknown"
> xlink:role="
> http://www.geosciml.org/geosciml/2.0/doc/GeoSciML/GeologicUnit/GeologicUnit.html
> "
> xlink:title="unknown"/>
>                <sa:position>
>                <gml:Point srsDimension="2"
> srsName="urn:x-ogc:def:crs:EPSG:4283">
>                <gml:pos>-37.574709832296264 142.5879533591661</gml:pos>
>                </gml:Point>
>                </sa:position>
>                <gwml:referenceElevation
> uom="http://www.opengis.net/def/uom/OGC/1.0/metre"/>
>                <gwml:wellDepth>
>                <gsml:CGI_NumericValue>
>                <gsml:principalValue
> uom="http://www.opengis.net/def/uom/OGC/1.0/metre
> ">9999.0</gsml:principalValue>
>                </gsml:CGI_NumericValue>
>                </gwml:wellDepth>
>                <gwml:wellStatus>
>                <gsml:CGI_TermValue>
>                <gsml:value codeSpace="
> http://www.dpi.vic.gov.au/agriculture">Unqualified
> </gsml:value>
>                </gsml:CGI_TermValue>
>                </gwml:wellStatus>
>                <gwml:wellType>
>                <gsml:CGI_TermValue>
>                <gsml:value
> codeSpace="http://www.dpi.vic.gov.au/agriculture">drilled</gsml:value>
>                </gsml:CGI_TermValue>
>                </gwml:wellType>
>                ...
>                </gwml:WaterWell>
>        </wfs:FeatureCollection>
>
>        versi_url =  "http://siss.versi.edu.au/geoserver/wfs";
>
>        versi_wfs_dpi = new OpenLayers.Layer.Vector("WFS", {
>                strategies: [new OpenLayers.Strategy.BBOX()],
>                projection: new OpenLayers.Projection('EPSG:4326'),
>                protocol: new OpenLayers.Protocol.WFS({
>                        url: versi_url,
>                        featureType: "WaterWell",
>                        featureNS: "http://www.nrcan.gc.ca/xml/gwml/1",
>                        featurePrefix: "gwml",
>                        version: "1.1.0",
>                        srsName: "EPSG:900913",
>                        geometryName: "sa:position",
>                        maxFeatures: 100,
>                        formatOptions: {
>                                externalProjection: new
> OpenLayers.Projection('EPSG:900913'),
>                                internalProjection: new
> OpenLayers.Projection('EPSG:4326')
>                        }
>                        //schema:
> "
> http://siss.versi.edu.au/geoserver/wfs/DescribeFeatureType?version=1.1.0&typename=gwml:Waterwell
> "
>
>                })
>        });
>
>        In Firebug we can see that features are returned but the bounds and
> geometry of each feature are null.
>
>        By manually changing the GML to gwml:position (which is not valid)
> we have
> confirmed that we can get points to appear on the map.
>
>
>
> http://osgeo-org.1803224.n2.nabble.com/file/n6961364/4-11-2011_12-06-15_PM.jpg
>
> --
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> http://osgeo-org.1803224.n2.nabble.com/Consuming-WFS-Complex-Features-tp6961364p6961364.html
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