schema supply and validation of input documents

[Konrad Lanz <Konrad.Lanz@labs.cio.gv.at>]

Dear all,

To accommodate Tommy's suggestions for <Schema>, <Schemas> with minor
amendments into the core the following changes are necessary:

_Add the SchemaRefs attribute to the <DocumentBaseType>_.
<xs:attribute name="SchemaRefs" type="xs:IDREFS" use="optional"/>

In the case of an input Document to be xml validated this will contain
only one ID, but in the case of a schema this will be used to import
other Schemas into the schema (a schema is also an xml document).

_Separate <Document> and DocumentType to be able to reuse DocumentType
for <Schema>_

<xs:element name="Document" type="dss:DocumentType"/>

<xs:complexType name="DocumentType">
  <xs:complexContent>
    <xs:extension base="dss:DocumentBaseType">
      <xs:choice>
        <xs:element name="InlineXML" type="dss:InlineXMLType"/>
        <xs:element name="Base64XML" type="xs:base64Binary"/>
        <xs:element name="EscapedXML" type="xs:string"/>
        <xs:element ref="dss:Base64Data"/>
      </xs:choice>
    </xs:extension>
  </xs:complexContent>
</xs:complexType>

_Add the optional input <Schema>_:

<xs:element name="Schema" type="dss:DocumentType"/>

Text for <Schema>:

RefUri: This uri if present MUST match the targetNamespace of the
contained Schema if present otherwise the uri extracted from the
targetNamespace is used.

Base64Data can be used for other not yet defined forms of verification
for CMS or whatever or an error can be thrown.

SchemaRefs[Optional]: This is used to point to all Schemas used in this
schema.

Add the Optional Input <Schemas>:

<xs:element name="Schemas" type="dss:SchemasType"/>
<xs:complexType name="SchemasType">
  <xs:sequence>
     <xs:element ref="dss:Schema" minOccurs="1" maxOccurs="unbounded"/>
  </xs:sequence>
</xs:complexType>

<Schemas> can be used for a set of Schemas used by a Document or other
Schema.
If it is referred to from a Document it is assumed that the Document is
validated against the first Schema and the other Schemas are assumed to
be used by the first Schema.

_Amended Text for 2.5.1 Type DocumentBaseType_:

SchemaRefs [Optional]
This may be used when the document contains XML documents or signatures.
It refers a single XML Schema [Schema1] which gives the ID attributes of
elements within the input document, which may be necessary if the
included signatures' <ds:Reference> elements use XPointer expressions or
<ds:Transforms> require it.
The <Schema> is to be used during parsing in sections 2.5.2, 3.3.1 1.a
and 4.3 and for XPath evaluation in sections 2.6, 3.5.7, 4.3.1 if they
are supplied.
If anything else but <Schemas>, <Schema> are referred to from here the
server MUST report an Error.
If a referred Schema is not used by the document this MAY be ignored or
reported to the client in the <Result>/<ResultMessage>.

_We also need to amend text for Document_:
SchemaRefs [Optional] :
  A Document shall only refer to a single <Schema> or <Schemas> element.
  If a <Schemas> element is referred to the document is validated
against the first <Schema> inside <Schemas> and the other <Schema>
elements are assumed to be used by the first <Schema>.

best regards
Konrad