src/foschema/schema2dtd.xsl

<?xml version="1.0"?>
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<!-- $Id$ -->
<xsl:stylesheet saxon:trace="no"
    version="1.1"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:saxon="http://icl.com/saxon"
    xmlns:xs = "http://www.w3.org/2001/XMLSchema"
    xmlns:fo="http://www.w3.org/1999/XSL/Format"
    xmlns:date="http://exslt.org/dates-and-times"
    xmlns:math="http://exslt.org/math"
    extension-element-prefixes="saxon date math"
    exclude-result-prefixes="fo">

<xsl:output method="xml" version="1.0" omit-xml-declaration="no" indent="yes"/>
<xsl:strip-space elements="*"/>

<xsl:template match="/xs:schema">
<xsl:text>
</xsl:text>
<xsl:comment>
 This DTD has been developed in order to validate XSL FO documents
 The namespace prefix is xmlns:fo="http://www.w3.org/1999/XSL/Format".

 In addition, the functionality implemented or not in FOP has been segregated
 To create an FOP only validating DTD, remove the references marked %\([a-zA-Z_]+\)_Not;
 I certainly have not exhaustively removed all of the properties not implemented in FOP.
 If you notice an item that is incorrectly included or excluded, please send me a note

 The FOP only DTD will not guard against the entering of attribute values not implemented by FOP
 (Such as fo:leader-pattern="use-content")
 See http://xml.apache.org/fop/implemented.html for more detailed restrictions

 It has not been well tested.
 For instance, the length attribute is able to be negative for some elements like margins.
 I have not represented that here.
 I have not added values for the Aural properties
 There are several instances where I've entered %integer_Type; and it should be positive-integer or number
 The DTD trys to handle the text based rules re: fo:markers, fo:float, footer and fo:initial-property-set
 But, allows you to do illegal things if you want because I couldn't figure out how to constrain against the illegal actions.

 Please e-mail your comments to cpaussa@myrealbox.com

</xsl:comment><xsl:text>
</xsl:text><xsl:comment> *************************************************************** </xsl:comment><xsl:text>
</xsl:text><xsl:comment> Entity definitions for groups of formatting objects             </xsl:comment><xsl:text>
</xsl:text><xsl:comment> *************************************************************** </xsl:comment><xsl:text>
</xsl:text>
  <xsl:apply-templates select="./xs:simpleType"/>
<xsl:text>
</xsl:text><xsl:comment> *************************************************************** </xsl:comment><xsl:text>
</xsl:text><xsl:comment> Attribute Groups                                                </xsl:comment><xsl:text>
</xsl:text><xsl:comment> *************************************************************** </xsl:comment>
  <xsl:apply-templates select="./xs:attributeGroup"/>
<xsl:text>
</xsl:text><xsl:comment> *************************************************************** </xsl:comment><xsl:text>
</xsl:text><xsl:comment> Element Groups                                                  </xsl:comment><xsl:text>
</xsl:text><xsl:comment> *************************************************************** </xsl:comment><xsl:text>
</xsl:text>
  <xsl:apply-templates select="./xs:group"/>
<xsl:text>
</xsl:text><xsl:comment> *************************************************************** </xsl:comment><xsl:text>
</xsl:text><xsl:comment> Elements                                                        </xsl:comment><xsl:text>
</xsl:text><xsl:comment> *************************************************************** </xsl:comment><xsl:text>
</xsl:text>
  <xsl:apply-templates select="./xs:element"/>
</xsl:template>

<xsl:template match="xs:group">
  <xsl:text disable-output-escaping="yes">
&lt;!ENTITY % </xsl:text><xsl:value-of select="./@name"/><xsl:text> "</xsl:text>
  <xsl:for-each select="./xs:choice/xs:element">
    <xsl:text>
  </xsl:text>
    <xsl:value-of select="./@ref"/>
    <xsl:if test="position() != last()">
      <xsl:text> |</xsl:text>
    </xsl:if>
  </xsl:for-each>
  <xsl:if test="./xs:choice/xs:group">
    <xsl:variable name="ref1">
      <xsl:call-template name="strip_fo">
        <xsl:with-param name="ref" select="./xs:choice/xs:group[1]/@ref"/>
      </xsl:call-template>
    </xsl:variable>
    <xsl:variable name="ref2">
      <xsl:call-template name="strip_fo">
        <xsl:with-param name="ref" select="./xs:choice/xs:group[2]/@ref"/>
      </xsl:call-template>
    </xsl:variable>
    <xsl:text>
  %</xsl:text>
    <xsl:value-of select="$ref1"/>
    <xsl:text>;</xsl:text>
    <xsl:if test="(/xs:schema/xs:group[@name = $ref1]/xs:choice/xs:element) and (/xs:schema/xs:group[@name = $ref2]/xs:choice/xs:element)">
      <xsl:text>| </xsl:text>
    </xsl:if>
    <xsl:text>
  %</xsl:text>
    <xsl:value-of select="$ref2"/><xsl:text>;</xsl:text>
  </xsl:if>
  <xsl:text disable-output-escaping="yes">
"&gt;</xsl:text>
</xsl:template>

<xsl:template match="xs:attributeGroup">
  <xsl:text disable-output-escaping="yes">
&lt;!ENTITY % </xsl:text><xsl:value-of select="./@name"/><xsl:text> "</xsl:text>
  <xsl:for-each select="./xs:attribute">
    <xsl:variable name="name">
      <xsl:call-template name="strip_fo">
        <xsl:with-param name="ref" select="./@name"/>
      </xsl:call-template>
    </xsl:variable>
    <xsl:variable name="type">
      <xsl:call-template name="strip_fo">
        <xsl:with-param name="ref" select="./@type"/>
      </xsl:call-template>
    </xsl:variable>
    <xsl:text>
  </xsl:text>
    <xsl:value-of select="$name"/>
    <xsl:choose>
      <xsl:when test="$type = 'xs:string'">
        <xsl:text> CDATA</xsl:text>
      </xsl:when>
      <xsl:when test="/xs:schema/xs:simpleType[@name = $type]/xs:restriction/xs:enumeration">
        <!--This item is a directly enumerated type-->
        <xsl:text> (%</xsl:text>
        <xsl:value-of select="$type"/>
        <xsl:text>;)</xsl:text>
      </xsl:when>
      <xsl:otherwise>
        <xsl:text> CDATA</xsl:text>
      </xsl:otherwise>
    </xsl:choose>
    <xsl:text> #IMPLIED</xsl:text>
  </xsl:for-each>
  <xsl:for-each select="./xs:attributeGroup">
    <xsl:variable name="ref">
      <xsl:call-template name="strip_fo">
        <xsl:with-param name="ref" select="./@ref"/>
      </xsl:call-template>
    </xsl:variable>
    <xsl:text>
  %</xsl:text><xsl:value-of select="$ref"/><xsl:text>;</xsl:text>
  </xsl:for-each>
  <xsl:text disable-output-escaping="yes">
  "&gt;</xsl:text>
</xsl:template>

<xsl:template match="xs:simpleType">
  <xsl:if test="./xs:restriction/xs:enumeration">
    <xsl:text disable-output-escaping="yes">
&lt;!ENTITY % </xsl:text><xsl:value-of select="./@name"/><xsl:text> "</xsl:text>
    <xsl:for-each select="./xs:restriction/xs:enumeration">
      <xsl:value-of select="./@value"/>
      <xsl:if test="position() != last()">
        <xsl:text>|</xsl:text>
      </xsl:if>
    </xsl:for-each>
    <xsl:text disable-output-escaping="yes">"&gt;</xsl:text>
  </xsl:if>
</xsl:template>

<xsl:template match="xs:element">
  <xsl:text disable-output-escaping="yes">&lt;!ELEMENT fo:</xsl:text>
  <xsl:value-of select="./@name"/>
  <xsl:choose>
    <xsl:when test="( not(./xs:complexType/xs:sequence) and not(./xs:complexType/xs:choice) )">
      <xsl:text> EMPTY</xsl:text>
    </xsl:when>
    <xsl:otherwise>
      <xsl:text> (</xsl:text>
      <xsl:if test="./xs:complexType/@mixed = 'true'">
        <xsl:text>#PCDATA|</xsl:text>
      </xsl:if>
      <xsl:for-each select="./xs:complexType/xs:sequence">
        <xsl:for-each select="./xs:element">
          <xsl:value-of select="./@ref"/>
          <xsl:call-template name="addPlus"/>
          <xsl:if test="position() != last()">
            <xsl:text>,</xsl:text>
          </xsl:if>
        </xsl:for-each>
        <xsl:for-each select="./xs:group">
          <xsl:text>%</xsl:text>
          <xsl:variable name="ref">
            <xsl:call-template name="strip_fo">
              <xsl:with-param name="ref" select="./@ref"/>
            </xsl:call-template>
          </xsl:variable>
          <xsl:value-of select="$ref"/>
          <xsl:text>;</xsl:text>
          <xsl:call-template name="addPlus"/>
          <xsl:if test="position() != last()">
            <xsl:text>,</xsl:text>
          </xsl:if>
        </xsl:for-each>
      </xsl:for-each>
      <xsl:for-each select="./xs:complexType/xs:choice">
        <xsl:for-each select="./xs:element">
          <xsl:value-of select="./@ref"/>
          <xsl:call-template name="addPlus"/>
          <xsl:if test="position() != last()">
            <xsl:text>|</xsl:text>
          </xsl:if>
        </xsl:for-each>
        <xsl:for-each select="./xs:group">
          <xsl:text>%</xsl:text>
          <xsl:variable name="ref">
            <xsl:call-template name="strip_fo">
              <xsl:with-param name="ref" select="./@ref"/>
            </xsl:call-template>
          </xsl:variable>
          <xsl:value-of select="$ref"/>
          <xsl:text>;</xsl:text>
          <xsl:call-template name="addPlus"/>
          <xsl:if test="position() != last()">
            <xsl:text>|</xsl:text>
          </xsl:if>
        </xsl:for-each>
      </xsl:for-each>
      <xsl:text>)</xsl:text>
    </xsl:otherwise>
  </xsl:choose>
  <xsl:for-each select="./xs:complexType/xs:sequence">
    <xsl:call-template name="addPlus"/>
  </xsl:for-each>
  <xsl:for-each select="./xs:complexType/xs:choice">
    <xsl:call-template name="addPlus"/>
  </xsl:for-each>
  <xsl:text disable-output-escaping="yes">&gt;
&lt;!ATTLIST fo:</xsl:text>
  <xsl:value-of select="./@name"/>
  <xsl:for-each select="./xs:complexType/xs:attribute">
    <xsl:variable name="name">
      <xsl:call-template name="strip_fo">
        <xsl:with-param name="ref" select="./@name"/>
      </xsl:call-template>
    </xsl:variable>
    <xsl:variable name="type">
      <xsl:call-template name="strip_fo">
        <xsl:with-param name="ref" select="./@type"/>
      </xsl:call-template>
    </xsl:variable>
    <xsl:text>
  </xsl:text>
    <xsl:value-of select="$name"/>
    <xsl:choose>
      <xsl:when test="$type = 'xs:string'">
        <xsl:text> CDATA</xsl:text>
      </xsl:when>
      <xsl:when test="/xs:schema/xs:simpleType[@name = $type]/xs:restriction/xs:enumeration">
        <!--This item is a directly enumerated type-->
        <xsl:text> (%</xsl:text>
        <xsl:value-of select="$type"/>
        <xsl:text>;)</xsl:text>
      </xsl:when>
      <xsl:otherwise>
        <xsl:text> CDATA</xsl:text>
      </xsl:otherwise>
    </xsl:choose>
    <xsl:choose>
      <xsl:when test="@use = 'required'">
        <xsl:text> #REQUIRED</xsl:text>
      </xsl:when>
      <xsl:otherwise>
        <xsl:text> #IMPLIED</xsl:text>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:for-each>
  <xsl:for-each select="./xs:complexType/xs:attributeGroup">
    <xsl:variable name="ref">
      <xsl:call-template name="strip_fo">
        <xsl:with-param name="ref" select="./@ref"/>
      </xsl:call-template>
    </xsl:variable>
    <xsl:text>
  %</xsl:text>
    <xsl:value-of select="$ref"/>
    <xsl:text>;</xsl:text>
  </xsl:for-each>
  <xsl:text disable-output-escaping="yes">
&gt;
</xsl:text>
</xsl:template>

<xsl:template name="addPlus">
  <xsl:choose>
    <xsl:when test="(@minOccurs = 0) and (@maxOccurs = 'unbounded')">
      <xsl:text>*</xsl:text>
    </xsl:when>
    <xsl:when test="(@minOccurs = 0) and ((@maxOccurs = 1) or not(@maxOccurs))">
      <xsl:text>?</xsl:text>
    </xsl:when>
    <xsl:when test="((@minOccurs = 1) or not(@minOccurs)) and (@maxOccurs = 'unbounded')">
      <xsl:text>+</xsl:text>
    </xsl:when>
    <xsl:when test="not(@minOccurs) and not(@maxOccurs)">
    </xsl:when>
    <xsl:otherwise>
      <xsl:text>!error!</xsl:text>
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

<xsl:template name="strip_fo">
  <xsl:param name="ref"/>
  <xsl:choose>
    <xsl:when test="substring($ref,1,3) = 'fo:'">
      <xsl:value-of select="substring($ref,4)"/>
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="$ref"/>
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

</xsl:stylesheet>