archive/org.eclipse.qvtd.build.etl.tests/schema/graphml-structure.xsd - mmt/org.eclipse.qvtd - Git at Google

 <?xml version="1.0"?>

 <xs:schema
     targetNamespace="http://graphml.graphdrawing.org/xmlns/graphml"

     xmlns="http://graphml.graphdrawing.org/xmlns/graphml"
     xmlns:g="http://graphml.graphdrawing.org/xmlns/graphml"
     xmlns:xs="http://www.w3.org/2001/XMLSchema"
     xmlns:xlink="http://www.w3.org/1999/xlink"

     elementFormDefault="qualified"
     attributeFormDefault="unqualified"
     >
   <xs:annotation>
     <xs:documentation
         source="http://graphml.graphdrawing.org/"
         xml:lang="en">
       The schema corresponding to this document defines the structural
       layer of the Graph Markup Language (GraphML).
       Although a DTD is provided, this schema is, together with its extensions
       http://graphml.graphdrawing.org/xmlns/1.0/graphml-attributes.xsd
       and
       http://graphml.graphdrawing.org/xmlns/1.0/graphml-parseinfo.xsd,
       the only normative reference.
     </xs:documentation>
   </xs:annotation>

   <xs:import namespace="http://www.w3.org/1999/xlink"
              schemaLocation="xlink.xsd">
     <xs:annotation>
       <xs:documentation
           xml:lang="en">
         Get access to the xlink attribute groups for the attributes
         xlink:href and xlink:type of locator.type.
       </xs:documentation>
     </xs:annotation>
   </xs:import>

   <xs:annotation>
     <xs:documentation
         source="http://graphml.graphdrawing.org/"
         xml:lang="en">
       The attribute groups &lt;element_name>.extra.attrib may be used
       for adding user defined attributes to the elements
       &lt;element_name>.
       The attribute group common.extra.attrib may be used for adding
       user defined attributes to all elements.
     </xs:documentation>
   </xs:annotation>


   <xs:attributeGroup name="common.extra.attrib"/>


   <xs:attributeGroup name="graphml.extra.attrib">
     <xs:attributeGroup ref="common.extra.attrib"/>
   </xs:attributeGroup>

   <xs:attributeGroup name="data.extra.attrib">
     <xs:attributeGroup ref="common.extra.attrib"/>
   </xs:attributeGroup>

   <xs:attributeGroup name="key.extra.attrib">
     <xs:attributeGroup ref="common.extra.attrib"/>
   </xs:attributeGroup>

   <xs:attributeGroup name="default.extra.attrib">
     <xs:attributeGroup ref="common.extra.attrib"/>
   </xs:attributeGroup>

   <xs:attributeGroup name="graph.extra.attrib">
     <xs:attributeGroup ref="common.extra.attrib"/>
   </xs:attributeGroup>

   <xs:attributeGroup name="node.extra.attrib">
     <xs:attributeGroup ref="common.extra.attrib"/>
   </xs:attributeGroup>

   <xs:attributeGroup name="edge.extra.attrib">
     <xs:attributeGroup ref="common.extra.attrib"/>
   </xs:attributeGroup>

   <xs:attributeGroup name="port.extra.attrib">
     <xs:attributeGroup ref="common.extra.attrib"/>
   </xs:attributeGroup>

   <xs:attributeGroup name="hyperedge.extra.attrib">
     <xs:attributeGroup ref="common.extra.attrib"/>
   </xs:attributeGroup>

   <xs:attributeGroup name="endpoint.extra.attrib">
     <xs:attributeGroup ref="common.extra.attrib"/>
   </xs:attributeGroup>

   <xs:attributeGroup name="locator.extra.attrib">
     <xs:attributeGroup ref="common.extra.attrib"/>
   </xs:attributeGroup>


   <xs:annotation>
     <xs:documentation
         source="http://graphml.graphdrawing.org/"
         xml:lang="en">
       Complex type definitions for the GraphML structural layer elements:
       &lt;data>, &lt;default>, &lt;key>, &lt;graphml>, &lt;graph>,
       &lt;node>, &lt;port>,
       &lt;edge>, &lt;hyperedge>, &lt;endpoint> and &lt;locator>.
       The names of the complex types are constructed corresponding
       to the pattern element_name.type.
       (The only remaining GraphML structural layer element
       &lt;desc> is of simple type xs:string.)
     </xs:documentation>
   </xs:annotation>


   <xs:complexType name="data-extension.type" mixed="true">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Extension mechanism for the content of &lt;data> and &lt;default>.
         The complex type data-extension.type is empty per default.
         Users may redefine this type in order to add content to
         the complex types data.type and default.type which are
         extensions of data-extension.type.
       </xs:documentation>
     </xs:annotation>
   </xs:complexType>


   <xs:complexType name="data.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Complex type for the &lt;data> element.
         data.type is mixed, that is, &lt;data> may contain #PCDATA.
         Content type: extension of data-extension.type which is empty
         per default.
       </xs:documentation>
     </xs:annotation>
     <xs:complexContent mixed="true">
       <xs:extension base="data-extension.type">
         <xs:attribute name="key" type="xs:NMTOKEN" use="required">
           <xs:annotation>
             <xs:documentation
                 source="http://graphml.graphdrawing.org/"
                 xml:lang="en">refers to the id attribute of a &lt;key>.
             </xs:documentation>
           </xs:annotation>
         </xs:attribute>
         <xs:attribute name="id" type="xs:NMTOKEN" use="optional">
           <xs:annotation>
             <xs:documentation
                 source="http://graphml.graphdrawing.org/"
                 xml:lang="en">identifies this &lt;data>.
             </xs:documentation>
           </xs:annotation>
         </xs:attribute>
         <xs:attributeGroup ref="data.extra.attrib">
           <xs:annotation>
             <xs:documentation
                 source="http://graphml.graphdrawing.org/"
                 xml:lang="en">
               user defined extra attributes for &lt;data> elements
             </xs:documentation>
           </xs:annotation>
         </xs:attributeGroup>
       </xs:extension>
     </xs:complexContent>
   </xs:complexType>


   <xs:complexType name="default.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Complex type for the &lt;default> element.
         default.type is mixed, that is, data may contain #PCDATA.
         Content type: extension of data-extension.type which is empty
         per default.
       </xs:documentation>
     </xs:annotation>
     <xs:complexContent mixed="true">
       <xs:extension base="data-extension.type">
         <xs:attributeGroup ref="default.extra.attrib">
           <xs:annotation>
             <xs:documentation
                 source="http://graphml.graphdrawing.org/"
                 xml:lang="en">
               user defined extra attributes for &lt;default> elements
             </xs:documentation>
           </xs:annotation>
         </xs:attributeGroup>
       </xs:extension>
     </xs:complexContent>
   </xs:complexType>


   <xs:simpleType name="key.for.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Simple type for the for attribute of &lt;key>.
         key.for.type is a restriction of xs:NMTOKEN
         Allowed values: all, graphml, graph, node, edge, hyperedge, port and endpoint.
       </xs:documentation>
     </xs:annotation>
     <xs:restriction base="xs:NMTOKEN">
       <xs:enumeration value="all"/>
       <xs:enumeration value="graph"/>
       <xs:enumeration value="node"/>
       <xs:enumeration value="edge"/>
       <xs:enumeration value="hyperedge"/>
       <xs:enumeration value="port"/>
       <xs:enumeration value="endpoint"/>
       <xs:enumeration value="graphml"/>
     </xs:restriction>
   </xs:simpleType>


   <xs:complexType name="key.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Complex type for the &lt;key> element.
       </xs:documentation>
     </xs:annotation>
     <xs:sequence>
       <xs:element ref="desc" minOccurs="0"/>
       <xs:element ref="default" minOccurs="0"/>
     </xs:sequence>
     <xs:attribute name="id" type="xs:NMTOKEN" use="required">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">identifies this &lt;key>.
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attribute name="for" type="key.for.type" default="all">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           describes the domain of definition for
           the corresponding graph attribute.
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attributeGroup ref="key.extra.attrib">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           user defined extra attributes for &lt;key> elements.
         </xs:documentation>
       </xs:annotation>
     </xs:attributeGroup>
   </xs:complexType>


   <xs:complexType name="graphml.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Complex type for the &lt;graphml> element.
       </xs:documentation>
     </xs:annotation>
     <xs:sequence>
       <xs:element ref="desc" minOccurs="0"/>
       <xs:element ref="key" minOccurs="0" maxOccurs="unbounded"/>
       <xs:sequence>
         <xs:choice minOccurs="0" maxOccurs="unbounded">
           <xs:element ref="graph"/>
           <xs:element ref="data"/>
         </xs:choice>
       </xs:sequence>
     </xs:sequence>
     <xs:attributeGroup ref="graphml.extra.attrib">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           user defined extra attributes for &lt;graphml> elements.
         </xs:documentation>
       </xs:annotation>
     </xs:attributeGroup>
   </xs:complexType>


   <xs:simpleType name="graph.edgedefault.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Simple type for the edgedefault attribute of &lt;graph>.
         graph.edgedefault.type is a restriction of xs:NMTOKEN
         Allowed values: directed, undirected.
       </xs:documentation>
     </xs:annotation>
     <xs:restriction base="xs:NMTOKEN">
       <xs:enumeration value="directed"/>
       <xs:enumeration value="undirected"/>
     </xs:restriction>
   </xs:simpleType>


   <xs:complexType name="graph.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Complex type for the &lt;graph> element.
       </xs:documentation>
     </xs:annotation>
     <xs:sequence>
       <xs:element ref="desc" minOccurs="0"/>
       <xs:choice>
         <xs:sequence>
           <xs:choice minOccurs="0" maxOccurs="unbounded">
             <xs:element ref="data"/>
             <xs:element ref="node"/>
             <xs:element ref="edge"/>
             <xs:element ref="hyperedge"/>
           </xs:choice>
         </xs:sequence>
         <xs:element ref="locator"/>
       </xs:choice>
     </xs:sequence>
     <xs:attributeGroup ref="graph.extra.attrib">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           user defined extra attributes for &lt;graph> elements.
         </xs:documentation>
       </xs:annotation>
     </xs:attributeGroup>
     <xs:attribute name="id" type="xs:NMTOKEN">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           identifies this graph .
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attribute name="edgedefault"
                   type="graph.edgedefault.type" use="required">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           describes whether edges of this graph are considered
           as directed or undirected per default (unless
           specified by the attribute directed of &lt;edge>).
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
   </xs:complexType>


   <xs:complexType name="node.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Complex type for the &lt;node> element.
       </xs:documentation>
     </xs:annotation>
     <xs:sequence>
       <xs:element ref="desc" minOccurs="0"/>
       <xs:choice>
         <xs:sequence>
           <xs:choice minOccurs="0" maxOccurs="unbounded">
             <xs:element ref="data"/>
             <xs:element ref="port"/>
           </xs:choice>
           <xs:element ref="graph" minOccurs="0"/>
         </xs:sequence>
         <xs:element ref="locator"/>
       </xs:choice>
     </xs:sequence>
     <xs:attributeGroup ref="node.extra.attrib">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           user defined extra attributes for &lt;node elements.
         </xs:documentation>
       </xs:annotation>
     </xs:attributeGroup>
     <xs:attribute name="id" type="xs:NMTOKEN" use="required">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           identifies this node.
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
   </xs:complexType>


   <xs:complexType name="port.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Complex type for the &lt;port> element.
       </xs:documentation>
     </xs:annotation>
     <xs:sequence>
       <xs:element ref="desc" minOccurs="0"/>
       <xs:choice minOccurs="0" maxOccurs="unbounded">
         <xs:element ref="data"/>
         <xs:element ref="port"/>
       </xs:choice>
     </xs:sequence>
     <xs:attributeGroup ref="port.extra.attrib">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           user defined extra attributes for &lt;port> elements.
         </xs:documentation>
       </xs:annotation>
     </xs:attributeGroup>
     <xs:attribute name="name" type="xs:NMTOKEN" use="required">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           identifies this port, within the node it is contained in.
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
   </xs:complexType>


   <xs:complexType name="edge.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Complex type for the &lt;edge> element.
       </xs:documentation>
     </xs:annotation>
     <xs:sequence>
       <xs:element ref="desc" minOccurs="0"/>
       <xs:element ref="data" minOccurs="0" maxOccurs="unbounded"/>
       <xs:element ref="graph" minOccurs="0"/>
     </xs:sequence>
     <xs:attributeGroup ref="edge.extra.attrib">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           user defined extra attributes for &lt;edge> elements.
         </xs:documentation>
       </xs:annotation>
     </xs:attributeGroup>
     <xs:attribute name="id" type="xs:NMTOKEN">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           identifies this edge .
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attribute name="directed" type="xs:boolean">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           overwrites the edgedefault attribute of &lt;graph> .
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attribute name="source" type="xs:NMTOKEN" use="required">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           points to the id attribute of the source &lt;node>.
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attribute name="target" type="xs:NMTOKEN" use="required">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           points to the id attribute of the target &lt;node>.
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attribute name="sourceport" type="xs:NMTOKEN">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           points to the name attribute of the source &lt;port>.
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attribute name="targetport" type="xs:NMTOKEN">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           points to the name attribute of the target &lt;port>.
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
   </xs:complexType>


   <xs:complexType name="hyperedge.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Complex type for the &lt;hyperedge> element.
       </xs:documentation>
     </xs:annotation>
     <xs:sequence>
       <xs:element ref="desc" minOccurs="0"/>
       <xs:choice minOccurs="0" maxOccurs="unbounded">
         <xs:element ref="data"/>
         <xs:element ref="endpoint"/>
       </xs:choice>
       <xs:element ref="graph" minOccurs="0"/>
     </xs:sequence>
     <xs:attributeGroup ref="hyperedge.extra.attrib">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           user defined extra attributes for &lt;hyperedge> elements.
         </xs:documentation>
       </xs:annotation>
     </xs:attributeGroup>
     <xs:attribute name="id" type="xs:NMTOKEN">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           identifies this &lt;hyperedge> .
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
   </xs:complexType>


   <xs:simpleType name="endpoint.type.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Simple type for the type attribute of &lt;endpoint>.
         endpoint.type.type is a restriction of xs:NMTOKEN
         Allowed values: in, out, undir.
       </xs:documentation>
     </xs:annotation>
     <xs:restriction base="xs:NMTOKEN">
       <xs:enumeration value="in"/>
       <xs:enumeration value="out"/>
       <xs:enumeration value="undir"/>
     </xs:restriction>
   </xs:simpleType>

   <xs:complexType name="endpoint.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Complex type for the &lt;endpoint> element.
       </xs:documentation>
     </xs:annotation>
     <xs:sequence>
       <xs:element ref="desc" minOccurs="0"/>
     </xs:sequence>
     <xs:attributeGroup ref="endpoint.extra.attrib">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           user defined extra attributes for &lt;endpoint> elements.
         </xs:documentation>
       </xs:annotation>
     </xs:attributeGroup>
     <xs:attribute name="id" type="xs:NMTOKEN">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           identifies this &lt;endpoint> .
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attribute name="port" type="xs:NMTOKEN">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           points to the name of the port, to which this endpoint is
           connected .
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attribute name="node" type="xs:NMTOKEN" use="required">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           points to the id of the node, to which this endpoint is connected.
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <xs:attribute name="type" type="endpoint.type.type" default="undir">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           defines the direction on this endpoint (undirected per default).
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
   </xs:complexType>


   <xs:complexType name="locator.type" final="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Complex type for the &lt;locator> element.
         Content type: (empty)
       </xs:documentation>
     </xs:annotation>
     <xs:attributeGroup ref="locator.extra.attrib">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           user defined extra attributes for &lt;locator> elements.
         </xs:documentation>
       </xs:annotation>
     </xs:attributeGroup>
     <xs:attribute ref="xlink:href" use="required">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           points to the resource of this locator.
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
     <!-- xs:attribute ref="xlink:type" fixed="simple"-->
     <xs:attribute ref="xlink:type">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           type of the hyperlink (fixed as simple).
         </xs:documentation>
       </xs:annotation>
     </xs:attribute>
   </xs:complexType>

   <!--========================================================-->

   <xs:element name="desc" type="xs:string" block="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: Provides human-readable descriptions for the GraphML
         element containing this &lt;desc> as its first child.
         Occurence: &lt;key>, &lt;graphml>, &lt;graph>,
         &lt;node>, &lt;port>, &lt;edge>, &lt;hyperedge>, and
         &lt;endpoint>.
       </xs:documentation>
     </xs:annotation>
   </xs:element>


   <xs:element name="locator" type="locator.type" block="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: Graphs and nodes are declared by the elements
         &lt;graph> and &lt;node>, respectively. The optional
         &lt;locator>-child of these elements point to
         their definition. (If there is no &lt;locator>-child
         the graphs/nodes are defined by their content).
         Occurence: &lt;graph>, and &lt;node>.
       </xs:documentation>
     </xs:annotation>
   </xs:element>

   <xs:element name="data" type="data.type" block="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: In GraphML there may be data-functions attached
         to graphs, nodes, ports, edges, hyperedges and
         endpoint and to the whole collection of
         graphs described by the content of &lt;graphml>.
         These functions are declared by &lt;key> elements
         (children of &lt;graphml>) and defined by &lt;data>
         elements.
         Occurence: &lt;graphml>, &lt;graph>, &lt;node>, &lt;port>,
         &lt;edge>, &lt;hyperedge>, and &lt;endpoint>.
       </xs:documentation>
     </xs:annotation>

     <xs:unique name="data_data_key_unique">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: uniqueness of the key attributes of &lt;data> children
           of this &lt;data> element.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath="./g:data"/>
       <xs:field xpath="@key"/>
     </xs:unique>

   </xs:element>


   <xs:element name="key" type="key.type" block="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: In GraphML there may be data-functions attached
         to graphs, nodes, ports, edges, hyperedges and
         endpoint and to the whole collection of
         graphs described by the content of &lt;graphml>.
         These functions are declared by &lt;key> elements
         (children of &lt;graphml>) and defined by &lt;data>
         elements.
         Occurence: &lt;graphml>.
       </xs:documentation>
     </xs:annotation>
   </xs:element>

   <xs:element name="default" type="default.type" block="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: In GraphML there may be data-functions attached
         to graphs, nodes, ports, edges, hyperedges and
         endpoint and to the whole collection of
         graphs described by the content of &lt;graphml>.
         These functions are declared by &lt;key> elements
         (children of &lt;graphml>) and defined by &lt;data>
         elements.
         The (optional) &lt;default> child of &lt;key> gives
         the default value for the corresponding function.
         Occurence: &lt;key>.
       </xs:documentation>
     </xs:annotation>
   </xs:element>

   <xs:element name="graphml" type="graphml.type" block="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: &lt;graphml> is the root element of each GraphML
         document.
         Occurence: root.
       </xs:documentation>
     </xs:annotation>

     <xs:unique name="graphml_data_key_unique">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: uniqueness of the key attributes of &lt;data> children
           of this &lt;graphml> element.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath="./g:data"/>
       <xs:field xpath="@key"/>
     </xs:unique>

     <xs:key name="key_id_key">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: existence and uniqueness of the id attributes of
           each &lt;key> element in this document.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath=".//g:key"/>
       <xs:field xpath="@id"/>
     </xs:key>


     <xs:unique name="graph_id_unique">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: uniqueness of the id attributes of
           each &lt;graph> element in this document.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath=".//g:graph"/>
       <xs:field xpath="@id"/>
     </xs:unique>

     <xs:keyref name="data_key_ref" refer="key_id_key">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: for the key attribute of each &lt;data> in this document,
           the existence of an id attribute of
           &lt;key> which matches the value of it.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath=".//g:data"/>
       <xs:field xpath="@key"/>
     </xs:keyref>

   </xs:element>


   <xs:element name="graph" type="graph.type" block="#all">

     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: Describes one graph in this document.
         Occurence: &lt;graphml>, &lt;node>, &lt;edge>, &lt;hyperedge>.
       </xs:documentation>
     </xs:annotation>

     <xs:unique name="graph_data_key_unique">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: uniqueness of the key attributes of &lt;data> children
           of this &lt;graph> element.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath="./g:data"/>
       <xs:field xpath="@key"/>
     </xs:unique>

     <xs:key name="node_id_key">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: existence and uniqueness of the id attributes of
           each &lt;node> element in this graph.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath=".//g:node"/>
       <xs:field xpath="@id"/>
     </xs:key>

     <xs:unique name="edge_id_unique">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: uniqueness of the id attributes of
           each &lt;edge> element in this graph.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath=".//g:edge"/>
       <xs:field xpath="@id"/>
     </xs:unique>

     <xs:unique name="hyperedge_id_unique">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: uniqueness of the id attributes of
           each &lt;hyperedge> element in this graph.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath=".//g:hyperedge"/>
       <xs:field xpath="@id"/>
     </xs:unique>

     <xs:unique name="endpoint_id_unique">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: uniqueness of the id attributes of
           each &lt;endpoint> element in this graph.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath=".//g:endpoint"/>
       <xs:field xpath="@id"/>
     </xs:unique>

     <xs:keyref name="edge_source_ref" refer="node_id_key">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: for the source attribute of each &lt;edge> in this graph,
           the existence of an id attribute of
           &lt;node> which matches the value of it.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath=".//g:edge"/>
       <xs:field xpath="@source"/>
     </xs:keyref>

     <xs:keyref name="edge_target_ref" refer="node_id_key">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: for the target attribute of each &lt;edge> in this graph,
           the existence of an id attribute of
           &lt;node> which matches the value of it.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath=".//g:edge"/>
       <xs:field xpath="@target"/>
     </xs:keyref>

     <xs:keyref name="endpoint_node_ref" refer="node_id_key">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: for the node attribute of each &lt;endpoint> in this graph,
           the existence of an id attribute of
           &lt;node> which matches the value of it.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath=".//g:endpoint"/>
       <xs:field xpath="@node"/>
     </xs:keyref>

   </xs:element>


   <xs:element name="node" type="node.type" block="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: Describes one node in the &lt;graph>
         containing this &lt;node>.
         Occurence: &lt;graph>.
       </xs:documentation>
     </xs:annotation>

     <xs:key name="port_name_key">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: existence and uniqueness of the name attributes of
           each &lt;port> element within this &lt;node>.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath=".//g:port"/>
       <xs:field xpath="@name"/>
     </xs:key>

     <xs:unique name="node_data_key_unique">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: uniqueness of the key attributes of &lt;data> children
           of this &lt;node> element.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath="./g:data"/>
       <xs:field xpath="@key"/>
     </xs:unique>

   </xs:element>


   <xs:element name="port" type="port.type" block="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: Nodes may be structured by ports; thus edges
         are not only attached to a node but to a certain
         port in this node.
         Occurence: &lt;node>, &lt;port>.
       </xs:documentation>
     </xs:annotation>

     <xs:unique name="port_data_key_unique">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: uniqueness of the key attributes of &lt;data> children
           of this &lt;port> element.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath="./g:data"/>
       <xs:field xpath="@key"/>
     </xs:unique>

   </xs:element>


   <xs:element name="edge" type="edge.type" block="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: Describes an edge in the &lt;graph> which contains this
         &lt;edge>.
         Occurence: &lt;graph>.
       </xs:documentation>
     </xs:annotation>

     <xs:unique name="edge_data_key_unique">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: uniqueness of the key attributes of &lt;data> children
           of this &lt;edge> element.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath="./g:data"/>
       <xs:field xpath="@key"/>
     </xs:unique>

   </xs:element>


   <xs:element name="hyperedge" type="hyperedge.type" block="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: While edges describe relations between two nodes,
         a hyperedge describes a relation between an arbitrary
         number of nodes.
         Occurence: &lt;graph>.
       </xs:documentation>
     </xs:annotation>

     <xs:unique name="hyperedge_data_key_unique">
       <xs:annotation>
         <xs:documentation
             source="http://graphml.graphdrawing.org/"
             xml:lang="en">
           Ensures: uniqueness of the key attributes of &lt;data> children
           of this &lt;hyperedge> element.
         </xs:documentation>
       </xs:annotation>
       <xs:selector xpath="./g:data"/>
       <xs:field xpath="@key"/>
     </xs:unique>

   </xs:element>


   <xs:element name="endpoint" type="endpoint.type" block="#all">
     <xs:annotation>
       <xs:documentation
           source="http://graphml.graphdrawing.org/"
           xml:lang="en">
         Description: The list of &lt;endpoints> within a hyperedge
         points to the nodes contained in this hyperedge.
         Occurence: &lt;hyperedge>.
       </xs:documentation>
     </xs:annotation>
   </xs:element>

 </xs:schema>

     <!--======================================================-->
     <!--      end of file: graphml-structure.xsd              -->
     <!--======================================================-->