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Copyright © 2010 Open Geospatial Consortium
NOTE Since previous OGC versions of this International Standard see OGC 02-058 and OGC 04-094 are bound to
specific versions of GML, a server may support previous versions of GML by advertising in its capabilities document see Table 12 that it supports previous OGC versions of this International Standard.
9.3 Response 9.3.1 Introduction
In response to a DescribeFeatureType request, where the value of the outputFormat parameter has been set to applicationgml+xml; version=3.2, a WFS implementation shall return a complete and valid GML see ISO
19136:2007 application schema that contains the definition of the feature types listed in the request. The documents returned by the DescribeFeatureType request may be used to validate feature instances
generated by the WFS in the form of feature collections on output or feature instances specified as input for transaction operations.
9.3.2 Supporting multiple namespaces
An XML Schema document can only declare elements in a single namespace see W3C XML Schema Part 2. In the event that a DescribeFeatureType operation requests that feature types in multiple namespaces be
described, the server shall generate the complete schema for one of the requested namespaces and import the remaining namespaces. This International Standard does not mandate which namespaces schema
should be generated and which namespaces should be imported.
EXAMPLE Consider the following request to describe feature types in multiple namespaces :
?xml version=1.0 ? DescribeFeatureType
version=2.0.0 service=WFS
xmlns=http:www.opengis.netwfs2.0 xmlns:ns01=http:www.server01.comns01
xmlns:ns02=http:www.server02.comns02 xmlns:xsi=http:www.w3.org2001XMLSchema-instance
xsi:schemaLocation=http:www.opengis.netwfs2.0
http:schemas.opengis.netwfs2.0.0wfs.xsd TypeNamens01:TreesA_1MTypeName
TypeNamens02:RoadL_1MTypeName DescribeFeatureType
A WFS might generate the following response to this request:
?xml version=1.0 ? xsd:schema
targetNamespace=http:www.server01.comns01 xmlns:ns01=http:www.server01.comns01
xmlns:xsd=http:www.w3.org2001XMLSchema elementFormDefault=qualified
attributeFormDefault=unqualified import namespace=http:www.server02.comns02
schemaLocation=http:www.yourserver.comwfs.cgi? REQUEST=DescribeFeatureTypeamp;TYPENAMES=ns02:RoadL_1M
xsd:element name=TREESA_1M type=ns01:TREESA_1MType substitutionGroup=gml:_Feature xsd:complexType name=TREESA_1MType
xsd:complexContent xsd:extension base=gml:AbstractFeatureType
-- list property declarations for feature type TREESA_1M -- xsd:extension
xsd:complexContent xsd:complexType
-- other declarations that are part of this schema -- xsd:schema
Copyright © 2010 Open Geospatial Consortium
59 9.4 Exceptions
In the event that a web feature service encounters an error parsing a DescribeFeatureType request, it shall raise an OperationParsingFailed exception as described in 7.5.
In the event that a web feature service encounters an error processing a DescribeFeatureType request, it shall raise an OperationProcessingFailed exception as described in 7.5.
10 GetPropertyValue operation
10.1 Introduction
The GetPropertyValue operation allows the value of a feature property or part of the value of a complex feature property to be retrieved from the data store for a set of features identified using a query expression
see 7.9.
10.2 Request 10.2.1 Request Semantics
Figure 15 describes the schema of a GetPropertyValue request.
BaseRequest + service : CharacterString = WFS {frozen}
+ version : CharacterString = 2. 0.0 {frozen} + handle [0..1] : CharacterString
GetPropertyValue + query : QueryE xpression
+ valueReference : ValueReference ResolveValue
+ local + remote
+ all + none
Enumeration {resolveDepth0 implies
resolvenone and resolveTimeout-notEmpty
implies resolvenone}
ResultType + results
+ hits Enumeration
StandardResolveParameters + resolve : ResolveValue = none
+ resolveDepth : UnlimitedInteger = isInfinite + resolveTimeout : TM_Duration = 300s
StandardPresentationParameters + resultType : ResultType = results
+ outputFormat : CharacterString = textxml; subty pe=gml 3... + count [0..1] : Integer
+ startIndex : Integer = 0 ResolveWithPath
+ resolvePath [0..1] : CharacterString
{query.oclIsTypeOfAdhocQuery or query. oclIsTypeOfStoredQuery}
Figure 15 — GetPropertyValue request 10.2.2 XML Encoding
The following XML fragment defines the XML encoding for the GetPropertyValue operation:
xsd:element name=GetPropertyValue type=wfs:GetPropertyValueType xsd:complexType name=GetPropertyValueType
xsd:complexContent xsd:extension base=wfs:BaseRequestType
xsd:sequence xsd:element ref=fes:AbstractQueryExpression
xsd:sequence
