A Conversion Tool from DTD to XML Schema

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dtd2xsd.pl

Note: the documentation below doesn't reflec the changes by MH; see her announcement of 11 Jan 2001 to xml-dev.

Usage:

perl dtd2xsd.pl [-alias] [-prefix p] [-ns n] [file]
  -alias
    enables special aliases (default off)
  -prefix t
    specify namespace prefix
  -ns http://www.w3.org/namespace/
    specify namespace URI
  -simpletype pattern base
    treat parameter entities whose name match this pattern
    as simple datatypes derived from this base type
  -attrgroup pattern
    treat parameter entities whose name match this pattern
    as attribute groups
  -modelgroup pattern
    treat parameter entities whose name match this pattern
    as model groups
If no file is specified, STDIN will be used.

Samples:

How does it work?

1. Encoding elements

DTD XML Schema 
<!ELEMENT ROOT (A,B) >

<element name="ROOT">
 <complexType content="elementOnly">
  <element ref="t:A">
  <element ref="t:B">
 </complexType>
<element>

<!ELEMENT ROOT (A|B) >

<element name="ROOT">
 <complexType content="elementOnly">
  <choice>
   <element ref="t:A">
   <element ref="t:B">
  </choice>
 </complexType>
<element>

<!ELEMENT ROOT (A|(B,C)) >

<element name="ROOT">
 <complexType content="elementOnly">
  <choice>
   <element ref="t:A">
   <sequence>
    <element ref="t:B">
    <element ref="t:C">
   </sequence>
  </choice>
 </complexType>
<element>

<!ELEMENT ROOT (A?,B+,C*) >

<element name="ROOT">
 <complexType content="elementOnly">
  <element ref="t:A" minOccurs="0">
  <element ref="t:B" maxOccurs="unbounded">
  <element ref="t:C" minOccurs="0" maxOccurs="unbounded">
 </complexType>
<element>

2. Encoding attributes

DTD XML Schema 
<!ATTLIST ROOT
    a CDATA #REQUIRED>

<element name="ROOT">
 <complexType content="elementOnly">
  <attribute name="a" type="string" use="required"/>
 </complexType>
<element>

<!ATTLIST ROOT
    a CDATA #IMPLIED>

<element name="ROOT">
 <complexType content="elementOnly">
  <attribute name="a" type="string" use="optional"/>
 </complexType>
<element>

<!ATTLIST ROOT
    a (x|y|z) #REQUIRED;>

<element name="ROOT">
 <complexType content="elementOnly">
  <attribute name="a">
   <simpleType base="string">
    <enumeration value="x"/>
    <enumeration value="y"/>
    <enumeration value="z"/>
   </simpleType>
  </attribute>
 </complexType>
<element>

<!ATTLIST ROOT
    a CDATA #FIXED "x">

<element name="ROOT">
 <complexType content="elementOnly">
  <attribute name="a" type="string" use="fixed" value="x"/>
 </complexType>
<element>

3. Simple Types, Attribute Groups, and Model Groups

Use dtd2xsd.pl -simpleType ContentType string to turn

<!ENTITY % ContentType "CDATA">
    <!-- media type, as per [RFC2045] -->

into

  <simpleType name='ContentType' base='string'>
  </simpleType>

@@along with references to %ContentType;

Use dtd2xsd.pl -simpleType Number nonNegativeInteger to turn

<!ENTITY % Number "CDATA">

into

  <simpleType name='Number' base='nonNegativeInteger'>
  </simpleType>

@@more on model groups, attribute groups. Meanwhile, see the makefile for examples.

History:

April 20 2000