<xsd:schema xmlns="http://www.ics.uci.edu/pub/arch/xArch/options.xsd"
            xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            xmlns:archtypes="http://www.ics.uci.edu/pub/arch/xArch/types.xsd"
            targetNamespace="http://www.ics.uci.edu/pub/arch/xArch/options.xsd"
            elementFormDefault="qualified"
            attributeFormDefault="qualified">

  <!-- Import types namespace -->
  <xsd:import namespace="http://www.ics.uci.edu/pub/arch/xArch/types.xsd"
              schemaLocation="http://www.isr.uci.edu/projects/xarchuci/ext/types.xsd"/>

  <xsd:annotation>
    <xsd:documentation>
      xArch Options XML Schema 1.0
      
      Depends on: {types.xsd}
      
      Change Log:
         2002-12-17: Eric M. Dashofy [edashofy@ics.uci.edu]:
           Added OptionalSignatureInterfaceMapping type.
         2002-05-18: Eric M. Dashofy [edashofy@ics.uci.edu]:
           Added OptionalInterface and OptionalSignature types.
         2002-01-28: Eric M. Dashofy [edashofy@ics.uci.edu]:
           Upgraded to 2001 XML Schema standard and validated
           with XML Spy 4.2.  Only changes were to the namespace
           declaration for 'xsd' in the header.
         2001-09-20: Eric M. Dashofy [edashofy@ics.uci.edu]:
           Changed Guard from a simple type to an abstract type
           to allow for proper extension thereof.
         2001-04-12: Eric M. Dashofy [edashofy@ics.uci.edu]:
           Cleaned up and validated with XML Spy 3.5.
         2000-10-13: Eric M. Dashofy [edashofy@ics.uci.edu]:
           Initial Development and validated with XSV

    </xsd:documentation>
  </xsd:annotation>

  <!--
    TYPE: Guard

    A Guard is some condition that, when satisfied, will 
    signal some sort of change in the architecture 
    (an optional component is included in the architecture 
    or a variant adheres to the selected type).  The specific 
    format of a guard is unspecified at this level.
   -->
  <xsd:complexType name="Guard" abstract="true"/>
  
  <!--
    TYPE: Optional
    
    Type that specifies a tag containing conditions that can be
    applied to a component, connector, or link if that component,
    connector, or link is optional in the architecture.
   -->
  <xsd:complexType name="Optional">
    <xsd:sequence>
      <xsd:element name="guard" type="Guard"/>
    </xsd:sequence>
  </xsd:complexType>
  
  <!--
    TYPE: OptionalComponent
    
    The OptionalComponent type extends the Component type
    to add the ability to make a component optional
    based on a guard.  This is a key feature for 
    configuration management.  Specification of
    optionality is optional.  
   -->
  <xsd:complexType name="OptionalComponent">
    <xsd:complexContent>
      <xsd:extension base="archtypes:Component">
        <xsd:sequence>
          <xsd:element name="optional" type="Optional"
                       minOccurs="0" maxOccurs="1"/>
        </xsd:sequence>
      </xsd:extension>
    </xsd:complexContent>
  </xsd:complexType>

  <!--
    TYPE: OptionalConnector
    
    The OptionalConnector type extends the Connector type
    to add the ability to make a connector optional
    based on a guard.  This is a key feature for 
    configuration management.  Specification of
    optionality is optional.  
   -->
  <xsd:complexType name="OptionalConnector">
    <xsd:complexContent>
      <xsd:extension base="archtypes:Connector">
        <xsd:sequence>
          <xsd:element name="optional" type="Optional"
                       minOccurs="0" maxOccurs="1"/>
        </xsd:sequence>
      </xsd:extension>
    </xsd:complexContent>
  </xsd:complexType>
  
  <!--
    TYPE: OptionalLink
    
    The OptionalLink type extends the Link type
    to add the ability to make a link optional.
    This is a key feature for configuration management.  
    Specification of optionality is optional.
   -->
  <xsd:complexType name="OptionalLink">
    <xsd:complexContent>
      <xsd:extension base="archtypes:Link">
        <xsd:sequence>
          <xsd:element name="optional" type="Optional"
                       minOccurs="0" maxOccurs="1"/>
        </xsd:sequence>
      </xsd:extension>
    </xsd:complexContent>
  </xsd:complexType>

  <!--
    TYPE: OptionalInterface
    
    The OptionalInterface type extends the Interface type
    to add the ability to make an interface optional.
    This is a key feature for configuration management.  
    Specification of optionality is optional.
   -->
  <xsd:complexType name="OptionalInterface">
    <xsd:complexContent>
      <xsd:extension base="archtypes:Interface">
        <xsd:sequence>
          <xsd:element name="optional" type="Optional"
                       minOccurs="0" maxOccurs="1"/>
        </xsd:sequence>
      </xsd:extension>
    </xsd:complexContent>
  </xsd:complexType>

  <!--
    TYPE: OptionalSignature
    
    The OptionalSignature type extends the Signature type
    to add the ability to make a signature optional.
    This is a key feature for configuration management.  
    Specification of optionality is optional.
   -->
  <xsd:complexType name="OptionalSignature">
    <xsd:complexContent>
      <xsd:extension base="archtypes:Signature">
        <xsd:sequence>
          <xsd:element name="optional" type="Optional"
                       minOccurs="0" maxOccurs="1"/>
        </xsd:sequence>
      </xsd:extension>
    </xsd:complexContent>
  </xsd:complexType>

  <!--
    TYPE: OptionalSignatureInterfaceMapping
    
    The OptionalSignatureInterfaceMapping type extends 
    the SignatureInterfaceMapping type to add the ability 
    to make a signature-interface mapping optional.
    This is a key feature for configuration management.  
    Specification of optionality is optional.
   -->
  <xsd:complexType name="OptionalSignatureInterfaceMapping">
    <xsd:complexContent>
      <xsd:extension base="archtypes:SignatureInterfaceMapping">
        <xsd:sequence>
          <xsd:element name="optional" type="Optional"
                       minOccurs="0" maxOccurs="1"/>
        </xsd:sequence>
      </xsd:extension>
    </xsd:complexContent>
  </xsd:complexType>

</xsd:schema>