<?xml version="1.0" encoding="UTF-8"?>
<!--
About this Schema:
  This schema describes the "Datastream Composite Model" format,
  a format for specifying the datastream requirements of a Fedora content
  model.  Example instances of this format can be found within the
  demo content model objects.  These datastreams have ID "DS_COMPOSITE_MODEL"
  and FORMAT_URI "info:fedora/fedora-system:FedoraDSCompositeModel-1.0".

Syntax:
  The root element, [dsCompositeModel], may contain any number of [dsTypeModel]
  child elements.  Each [dsTypeModel] element must have an ID attribute,
  and may contain any number of [form] child elements.  Each [form] element
  may have a FORMAT_URI attribute and/or a MIME attribute.

Semantics:
  A [dsCompositeModel] specifies a minimal set of datastream requirements that
  must be met by conforming objects.  If the set of requirements is met,
  an object can be said to conform to the model.  Note that conforming objects
  may contain additional datastreams that are not required by the model.

  A [dsTypeModel] specifies the ID of a datastream that must exist in
  conforming objects, and optionally, a set of format requirements, via
  the [form] element.

  For a given [dsTypeModel]:
  - If no [form] child elements are present, the model does not constrain
    the format of conforming datastreams.
  - If one or more [form] child elements are present, conforming datastreams
    must match at least one.
    
  For a given [form]:
  - A candidate datastream matches if the datastream's MIME type matches
    that given in the MIME attribute (if any), AND the datastream's
    FORMAT_URI matches that given in the FORMAT_URI attribute (if any).
  - If the MIME attribute is not present, the candidate datastream's MIME type
    is not constrained by that format requirement.
  - If the FORMAT_URI attribute is not present, the candidate datastream's
    FORMAT_URI is not constrained by that format requirement.
-->
<xsd:schema
    targetNamespace="info:fedora/fedora-system:def/dsCompositeModel#"
    xmlns="info:fedora/fedora-system:def/dsCompositeModel#"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    elementFormDefault="qualified"
    attributeFormDefault="unqualified">
  <xsd:element name="dsCompositeModel">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element minOccurs="0" maxOccurs="unbounded" ref="dsTypeModel"/>
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="dsTypeModel">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element minOccurs="0" maxOccurs="unbounded" ref="form"/>
      </xsd:sequence>
      <xsd:attribute name="ID" use="required" type="xsd:NCName"/>
    </xsd:complexType>
  </xsd:element>
  <xsd:element name="form">
    <xsd:complexType>
      <xsd:attribute name="FORMAT_URI" use="optional" type="xsd:anyURI"/>
      <xsd:attribute name="MIME" use="optional"/>
    </xsd:complexType>
  </xsd:element>
</xsd:schema>