19.1.6.Special Attributes of Web Resources

The Virtuoso WebDAV implementation provides a set of special attributes (properties) for the resources to manipulate the retrieval of XML documents. Properties can be set generate dynamic content based on XML/SQL queries. Special properties can also be applied to WebDAV folders for storing XML data in a special pre-parsed persistent XML format.

The following special properties are supported:

  • xml-stylesheet. must contain a valid URL to an XSLT style sheet. Upon request of an XML document with this property set, the WebDAV server will automatically perform the transformation of the XML document and will send the result of transformation to the user-agent instead of the original XML source. This property is only settable for documents having MIME type text/xml.

  • xml-sql. must contain a valid XML/SQL query (see also: FOR XML statements ). When this property is set the server will execute the query and the XML result will be sent to the client. Note that if xml-stylesheet is also supplied for this resource the result will be transformed and then sent to the client.

  • xml-sql-root. specifies the root element name of automatically generated XML resources when xml-sql is specified. Otherwise it has no effect.

  • xml-sql-dtd. can be specified as a string value 'on' or valid URL. When the value is 'on' the DTD declaration will be implied in the automatically generated XML resource. Otherwise when the URL is supplied this URL will be included in the DTD declaration of the automatically generated XML resource. If xml-sql is not specified this property has no effect.

  • xml-sql-schema. specifies the URI for the XML Schema. This schema URI will be included in the XML header, to allow client-side schema validation. If xml-sql is not specified this property has no effect.

  • xper. can be specified for a collection (folder). When this property is set on a WebDAV collection, the direct resource members will be stored and updated as persistent XML. Note that existing resources will not be changed until they are updated. The reversal of this property for collections will not change the resources at the same time, they will be reverted to the text/xml storage on first update operation. Resources already stored as XML persistent documents also have the xper property set, but manipulation of this property must not be used to revert the storage.