gml:Edge

gml:Edge represents the 1-dimensional primitive.
The topological boundary of an Edge (gml:directedNode) consists of a negatively directed start Node and a positively directed end Node.   
The optional coboundary of an edge (gml:directedFace) is a circular sequence of directed faces which are incident on this edge in document order. In the 2D case, the orientation of the face on the left of the edge is "+"; the orientation of the face on the right on its right is "-". 
If provided, the aggregationType attribute shall have the value "sequence".
An edge may optionally be realised by a 1-dimensional geometric primitive (gml:curveProperty).

Element information

Content

• Sequence [1..1]
  from type gml:AbstractGMLType
  from group gml:StandardObjectProperties
  gml:metaDataProperty [0..*]
  gml:description [0..1]The value of this property is a text description of the object. gml:description uses gml:StringOrRefType as its content model, so it may contain a simple text string content, or carry a reference to an external description. The use of gml:description to reference an external description has been deprecated and replaced by the gml:descriptionReference property.
  gml:descriptionReference [0..1]The value of this property is a remote text description of the object. The xlink:href attribute of the gml:descriptionReference property references the external description.
  gml:identifier [0..1]Often, a special identifier is assigned to an object by the maintaining authority with the intention that it is used in references to the object For such cases, the codeSpace shall be provided. That identifier is usually unique either globally or within an application domain. gml:identifier is a pre-defined property for such identifiers.
  gml:name [0..*]The gml:name property provides a label or identifier for the object, commonly a descriptive name. An object may have several names, typically assigned by different authorities. gml:name uses the gml:CodeType content model. The authority for a name is indicated by the value of its (optional) codeSpace attribute. The name may or may not be unique, as determined by the rules of the organization responsible for the codeSpace. In common usage there will be one name per authority, so a processing application may select the name from its preferred codeSpace.
  1. gml:container [0..1]
  2. gml:directedNode [2..2]A gml:directedNode property element describes the boundary of topology edges and is used in the support of topological point features via the gml:TopoPoint expression, see below. The orientation attribute of type gml:SignType expresses the sense in which the included node is used: start ("-") or end ("+") node.
  3. gml:directedFace [0..*]The gml:directedFace property element describes the boundary of topology solids, in the coBoundary of topology edges and is used in the support of surface features via the gml:TopoSurface expression, see below. The orientation attribute of type gml:SignType expresses the sense in which the included face is used i.e. inward or outward with respect to the surface normal in any geometric realisation.
  4. gml:curveProperty [0..1]This property element either references a curve via the XLink-attributes or contains the curve element. curveProperty is the predefined property which may be used by GML Application Schemas whenever a GML feature has a property with a value that is substitutable for AbstractCurve.

Attributes

Used in

• Type gml:ArrayAssociationType (Element gml:members)
• Type gml:DirectedEdgePropertyType (Element gml:directedEdge)
• Type gml:NodeOrEdgePropertyType (Element gml:isolated)
• Type gml:TopoPrimitiveArrayAssociationType (Element gml:topoPrimitiveMembers)
• Type gml:TopoPrimitiveMemberType (Element gml:topoPrimitiveMember)

Substitution hierarchy

• gml:AbstractObject
  • can be substituted with gml:AbstractGML
    • can be substituted with gml:AbstractTopology
      • can be substituted with gml:AbstractTopoPrimitive
        • can be substituted with gml:Edge

Sample instance

<gml:Edge gml:id="ID">
   <gml:metaDataProperty>
      <gml:GenericMetaData>Any text, intermingled with:
         <!--any element-->
      </gml:GenericMetaData>
   </gml:metaDataProperty>
   <gml:description>string</gml:description>
   <gml:descriptionReference/>
   <gml:identifier codeSpace="http://www.example.com/">string</gml:identifier>
   <gml:name>string</gml:name>
   <gml:container>
      <gml:TopoSolid gml:id="ID">
         <gml:metaDataProperty>...
         </gml:metaDataProperty>
         <gml:description>string</gml:description>
         <gml:descriptionReference/>
         <gml:identifier codeSpace="http://www.example.com/">string</gml:identifier>
         <gml:name>string</gml:name>
         <gml:isolated>...
         </gml:isolated>
         <gml:directedFace>...
         </gml:directedFace>
         <gml:solidProperty>...
         </gml:solidProperty>
      </gml:TopoSolid>
   </gml:container>
   <gml:directedNode>
      <gml:Node gml:id="ID">
         <gml:metaDataProperty>...
         </gml:metaDataProperty>
         <gml:description>string</gml:description>
         <gml:descriptionReference/>
         <gml:identifier codeSpace="http://www.example.com/">string</gml:identifier>
         <gml:name>string</gml:name>
         <gml:container>...
         </gml:container>
         <gml:directedEdge>...
         </gml:directedEdge>
         <gml:pointProperty>...
         </gml:pointProperty>
      </gml:Node>
   </gml:directedNode>
   <gml:directedFace>
      <gml:Face gml:id="ID">
         <gml:metaDataProperty>...
         </gml:metaDataProperty>
         <gml:description>string</gml:description>
         <gml:descriptionReference/>
         <gml:identifier codeSpace="http://www.example.com/">string</gml:identifier>
         <gml:name>string</gml:name>
         <gml:isolated>...
         </gml:isolated>
         <gml:directedEdge>...
         </gml:directedEdge>
         <gml:directedTopoSolid>...
         </gml:directedTopoSolid>
         <gml:surfaceProperty>...
         </gml:surfaceProperty>
      </gml:Face>
   </gml:directedFace>
   <gml:curveProperty>
      <gml:LineString gml:id="ID">
         <gml:metaDataProperty>...
         </gml:metaDataProperty>
         <gml:description>string</gml:description>
         <gml:descriptionReference/>
         <gml:identifier codeSpace="http://www.example.com/">string</gml:identifier>
         <gml:name>string</gml:name>
         <gml:pos>1.0 1.0</gml:pos>
      </gml:LineString>
   </gml:curveProperty>
</gml:Edge>