The WebComposition/DGS provides a default adapter for managing XML-based lists. If required, this capability of the WebComposition/DGS can be extended by providing additional data adapters. To enable a different data adapter, specify the corresponding adapter in the Web.config file as follows. The type used, must be a assembly-qualified name. Read about the concept of fully qualified type names for further information.

<webComposition>
    <dataGridService>
        <dataAdapter type="WebComposition.Dgs.Data.XmlDataAdapter,
                           WebComposition.Dgs.Data,
                           Version=1.0.0.0,
                           Culture=neutral,
                           PublicKeyToken=3abf3756ad264e35"
                     contentType="text/xml"
                     schemaScope="None">
            <metaData inputNotation="RDF/N3"
                      outputNotation="RDF/XML">
        </dataAdapter>
        ....
    </dataGridService>
    ...
</webComposition>

The contentType attribute specified, denotes that the specified data adapter is used if a request does provide the corresponding content type in its headers. If no content type is specified by the request, the default adapter is used. The contentType attribute for the default data adapter must be emtpy.

<webComposition>
    <dataGridService>
    ...
        <defaultDataAdapter type="WebComposition.Dgs.Data.XmlDataAdapter,
                                  WebComposition.Dgs.Data,
                                  Version=1.0.0.0,
                                  Culture=neutral,
                                  PublicKeyToken=3abf3756ad264e35"
                            contentType=""
                            schemaScope="None">
            <metaData inputNotation="RDF/N3"
                      outputNotation="RDF/XML">
        </defaultDataAdapter>
        ...
    </dataGridService>
    ...
</webComposition>

The WebComposition/DGs can be applied to a varying range of application with different requirements on flexibility. Therefore, the WebComposition/DGS DataGridService and supports different levels of schema validation using the schemaScope attribute. The schemaScope attribute defines whether the data adapter requires XML schemas for validation or not. 

• None
  Turns off schema validation. Trying to add a schema to a list will cause an error.
• List
  The schema is applied to the overall list. The root node of the list must be defined as well in the schema provided.
• Element
  The schema is applied to the elements in the list. The list itself is not part of the validation. Each element within this list is validated agains the list provided.

<webComposition>
    <dataGridService>
        <dataAdapter type="WebComposition.Dgs.Data.XmlDataAdapter,
                           WebComposition.Dgs.Data,
                           Version=1.0.0.0,
                           Culture=neutral,
                           PublicKeyToken=3abf3756ad264e35"
                      contentType="text/xml"
                      schemaScope="None">
            <metaData inputNotation="RDF/N3"
                      outputNotation="RDF/XML">  
        </dataAdapter>
        ...
    </dataGridService>
    ...
</webComposition>

Following the concept of Linked Data all information (data in form of resources as well as their relationships) within the WebComposition/DGS is linked by meta data. Within the WebComposition/DGS, this data is processed by a dedicated meta store that internally deals with the information described by RDF.

While processed internally described by RDF, the WebComposition/DGS privdes the flexibility to specify filters for specific representation of meta information other than RDF. Additional filters are specified within the Web.config as below. The type used for a filter, must be a assembly-qualified name. Read about the concept of fully qualified type names for further information.

<webComposition>
    <dataGridService>
        <inputFilters>
            <filter name="RDF/N3"
                    type="WebComposition.Dgs.Content.Meta.N3Filter,
                          WebComposition.Dgs.Content,
                          Version=1.0.0.0,
                          Culture=neutral,
                          PublicKeyoken=null" />
            ....
        </inputFilters>
        <outputFilters>
            <filter name="RDF/XML"
                    type="WebComposition.Dgs.Content.Meta.RdfFilter,
                          WebComposition.Dgs.Content,
                          Version=1.0.0.0,
                          Culture=neutral,
                          PublicKeyToken=null"/>
            ...
        </outputFilters>
        ... 
        <dataAdapter type="WebComposition.Dgs.Data.XmlDataAdapter,
                           WebComposition.Dgs.Data,
                           Version=1.0.0.0,
                           Culture=neutral,
                           PublicKeyToken=3abf3756ad264e35"
                      contentType="text/xml"
                      schemaScope="None">
            <metaData inputNotation="RDF/N3"
                      outputNotation="RDF/XML">  
        </dataAdapter>
        ...
    </dataGridService>
    ...
</webComposition>

The inputNotation and outputNotation attributes define which input and output filters should be used with the given data adapter.

To activate REST-style URLs for the WebComposition DataGridService (ommiting the extension .svc for Windows Communication Foundation services) activate the correpsonding HTTP module for Internet Information Services (IIS)  by applying the following settings in the Web.config file. This module is tested for Windows XP, Windows Vista and Windows Server 2008. 

<system.webServer>
    <modules>
        <add name="WebComposition.Dgs.RestHttpModule"
             type="WebComposition.Dgs.RestHttpModule" />
    </modules>
</system.webServer>