<xs:schema targetNamespace="http://ltsc.ieee.org/xsd/LOM"
           xmlns="http://ltsc.ieee.org/xsd/LOM"
           xmlns:ag="http://ltsc.ieee.org/xsd/LOM/unique"
           xmlns:ex="http://ltsc.ieee.org/xsd/LOM/extend"
           xmlns:xs="http://www.w3.org/2001/XMLSchema"
           elementFormDefault="qualified"
           version="IEEE LTSC LOM XML 1.0">

   <xs:annotation>
      <xs:documentation>
         This work is licensed under the Creative Commons Attribution-ShareAlike
         License.  To view a copy of this license, see the file license.txt,
         visit http://creativecommons.org/licenses/by-sa/2.0 or send a letter to
         Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA.
      </xs:documentation>

      <xs:documentation>
         This component schema defintion defines global schema data type declarations
         for data types defined in the LOMv1.0 base schema.
      </xs:documentation>
      <xs:documentation>
        *****************************************************************************
        **                                                                         ** 
        ** NOTE THIS CHANGE HISTORY IS USED TO DOCUMENT CHANGES TO THE XML SCHEMA  **
        ** DEFINITION DURING THE BALLOTING PROCESS.  THIS CHANGE HISTORY WILL BE   **
        ** REMOVED ONCE THE FINAL VERSION OF THE STANDARD IS PUBLISHED.  A NEW     **
        ** CHANGE HISTORY WILL BE INCLUDED TO INDICATE THE INITIAL RELEASE THAT    **
        ** MAPS TO THE FINAL STANDARD.                                             **
        **                                                                         **
        *****************************************************************************
        **                            CHANGE HISTORY                               **
        *****************************************************************************
        ** 11/14/2003:  1)Updated xs:pattern for the DurationString.  The pattern  **
        **                did not permit zero values for each of the date and      **
        **                time components.                                         **
        **                                                                         **
        ** 03/15/2004:  1)Changed the restriction type for LanguageIdNone from     **
        **                xs:string to xs:token                                    **
        **                                                                         ** 
        ** 08/24/2004:  1) To correct a XML Binding to Marshalling issue, a change **
        **              is needed to resolve a naming convention for two complex   **
        **              types:                                                     **       
        **                1.1) Changed the name of the LangString complexType      **
        **                to LanguageString                                        **
        **                1.2) Change the  name of the langString completType to   **
        **                LangString                                               **
        **              2)Updated the Creative Commons Licensing agreement to      **
        **                reference the Attribution-ShareAlike 2.0                 **
        **                                                                         ** 
        ** 09/27/2004   1)Updated file documentation to correspond with working    **
        **                draft 3.                                                 **
        **              2)Removed the LanguageIdOrNone and LanguageIdNone type     **
        **                declarations.  The types were not needed.  The           **
        **                LanguageId type was updated to support attribute         **
        **                extensions.  The LanguageId will now vaidate any         **
        **                language defined by 1484.12.3 and the token "none".      **
        **              3)Updated VCard to support attribute extensions.           **
        **              4)Updated LanguageString to reference the xs:language      **
        **                data type.                                               **       
        **              5)Updated DateTimeValue to support attribute extensions.   **
        **              6)Updated DurationValue to support attribute extensions.   **
        *****************************************************************************
      </xs:documentation>
   </xs:annotation>

   <xs:import namespace="http://ltsc.ieee.org/xsd/LOM/unique" />
   <xs:import namespace="http://ltsc.ieee.org/xsd/LOM/extend" />

   <!-- Data type declarations -->

   <!-- CharacterString -->
   <xs:simpleType name="CharacterString">
      <xs:restriction base="xs:string"/>
   </xs:simpleType>

   <!-- LanguageId -->
   <xs:complexType name="LanguageId">
       <xs:simpleContent>
         <xs:extension base="xs:language">
            <xs:attributeGroup ref="ex:customAttributes"/>
         </xs:extension>
      </xs:simpleContent>
   </xs:complexType>

   <!-- VCard -->
   <xs:complexType name="VCard">
       <xs:simpleContent>
         <xs:extension base="CharacterString">
            <xs:attributeGroup ref="ex:customAttributes"/>
         </xs:extension>
      </xs:simpleContent>
   </xs:complexType>

   <!-- MimeType -->
   <xs:simpleType name="MimeType">
      <xs:restriction base="CharacterString"/>
   </xs:simpleType>

   <!-- Size -->
   <xs:simpleType name="Size">
      <xs:restriction base="xs:nonNegativeInteger"/>
   </xs:simpleType>

   <!-- LanguageString -->
   <xs:complexType name="LanguageString">
      <xs:choice minOccurs="0" maxOccurs="unbounded">
         <xs:element name="string" type="LangString"/>
         <xs:group ref="ex:customElements"/>
      </xs:choice>
      <xs:attributeGroup ref="ex:customAttributes"/>
   </xs:complexType>

   <xs:complexType name="LangString">
      <xs:simpleContent>
         <xs:extension base="CharacterString">
            <xs:attribute name="language" type="xs:language"/>
            <xs:attributeGroup ref="ex:customAttributes"/>
         </xs:extension>
      </xs:simpleContent>
   </xs:complexType>

   <!-- DateTime -->
   <xs:complexType name="DateTime">
      <xs:choice minOccurs="0" maxOccurs="unbounded">
         <xs:element name="dateTime" type="DateTimeValue"/>
         <xs:element name="description" type="description"/>
         <xs:group ref="ex:customElements"/>
      </xs:choice>
   </xs:complexType>

   <xs:complexType name="DateTimeValue">
      <xs:simpleContent>
         <xs:extension base="DateTimeString">
           <xs:attributeGroup ref="ag:DateTimeValue"/>
           <xs:attributeGroup ref="ex:customAttributes"/>
         </xs:extension>
      </xs:simpleContent>
   </xs:complexType>

   <!-- Regular expresion from Christian Klaue -->
   <xs:simpleType name="DateTimeString">
      <xs:restriction base="CharacterString">
         <xs:pattern value="([0-9]{3}[1-9]|[0-9]{2}[1-9][0-9]|[0-9][1-9][0-9]{2}|[1-9][0-9]{3})(\-(0[1-9]|1[0-2])(\-(0[1-9]|[1-2][0-9]|3[0-1])(T([0-1][0-9]|2[0-3])(:[0-5][0-9](:[0-5][0-9](\.[0-9]{1,}(Z|((\+|\-)([0-1][0-9]|2[0-3]):[0-5][0-9]))?)?)?)?)?)?)?"/>
      </xs:restriction>
   </xs:simpleType>

   <!-- Duration -->
   <xs:complexType name="Duration">
      <xs:choice minOccurs="0" maxOccurs="unbounded">
         <xs:element name="duration" type="DurationValue"/>
         <xs:element name="description" type="description"/>
         <xs:group ref="ex:customElements"/>
      </xs:choice>
   </xs:complexType>

   <xs:complexType name="DurationValue">
      <xs:simpleContent>
         <xs:extension base="DurationString">
            <xs:attributeGroup ref="ag:DurationValue"/>
            <xs:attributeGroup ref="ex:customAttributes"/>
         </xs:extension>
      </xs:simpleContent>
   </xs:complexType>

   <!-- Regular expresion from Christian Klaue -->
   <xs:simpleType name="DurationString">
      <xs:restriction base="CharacterString">
         <xs:pattern value="P([0-9]{1,}Y){0,1}([0-9]{1,}M){0,1}([0-9]{1,}D){0,1}(T([0-9]{1,}H){0,1}([0-9]{1,}M){0,1}([0-9]{1,}(\.[0-9]{1,}){0,1}S){0,1}){0,1}"/>
      </xs:restriction>
   </xs:simpleType>

</xs:schema>