Purpose

Execute WSDL interfaces to answer user queries.

Procedure

• Identify the information in web services.
  • annotate existing descriptions
• Query that specific information.
• Automatically invoke the appropriate service(s).

Description Annotations

a sawsdl:loweringSchemaMapping:

      <xs:element name="Item">
        <xs:complexType sawsdl:loweringSchemaMapping=
	'http://dev.w3.org/cvsweb/perl/modules/W3C/SPDL/descriptions/AWSECommerceService-SAWSDL-item-terms.ttl#title'>
	  <xs:sequence>
	    <xs:element name="Author" type="xs:string" minOccurs="0" maxOccurs="unbounded"/>
	    <!-- ... -->
	    <xs:element name="Title" type="xs:string" minOccurs="0"/>
	  </xs:sequence>
	</xs:complexType>
      </xs:element>

points to:

:id spat:SPAT '?req :id xpath(".")' .
:keywords spat:SPAT '?req :keywords xpath("tns:Keywords") ; :index    xpath("tns:SearchIndex")' .
:asin spat:SPAT '?book :asin xpath("tns:ASIN")' .
:title spat:SPAT '?book tns:docTitle xpath("aws:Title")' .

Shortcut notation

      <xs:element name="Item">
        <xs:complexType spat:SPAT='?book tns:doctitle xpath("aws:Title")>
	  <xs:sequence>
	    <xs:element name="Author" type="xs:string" minOccurs="0" maxOccurs="unbounded"/>
	    <!-- ... -->
	    <xs:element name="Title" type="xs:string" minOccurs="0"/>
	  </xs:sequence>
	</xs:complexType>
      </xs:element>

Identifying information

• Using SPARQL Annotations (SPARQL + XPath) in WSDL:
  • SPARQL: SQL-like RDF query language

    SELECT ?tile WHERE { ?response tnss:doctitle ?title }

  • XPath: identify locations in a document

    aws:ItemSearchResponse/aws:Items/aws:Item/aws:Title

  • WSDL: associate messages (documents) with services

    <definitions><types><element name="ItemSearchResponse"></element></types>...
        <message name="ItemSearchResponseMsg"/></definitions>

• SPARQL annotations tie RDF data to locations in a Web Services message.

  • <xs:element name="Item" spat:SPAT='?book tns:doctitle xpath("aws:Title")'/>