Question

I’m trying to write a schema for some XML that is like HTML.
It has < b >< u >< i >< font >< img > tags all inside < p >(aragraph) tags. The problem is they can be in any order:

<p> <u><b>test</u><b> </p>

or

<p> <b><u>test</u></b> </p>.

I am trying to create a self referential complex type but I always get “invalid schema” errors. If anyone can guide me to the correct way to do this I would be much appreciated.

Schema:

<xs:element name="HTMLDocument">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="p" type="textElements" minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>

<xs:complexType name="textElements" mixed="true">
  <xs:group>
    <xs:element name="b" type="textElements"/>
    <xs:element name="i" type="textElements"/>
    <xs:element name="u" type="textElements"/>
    <xs:element name="a" type="textElements"/>
    <xs:element name="font" type="textElements">
      <xs:complexType>
        <xs:attribute name="size" type="xs:string"/>
        <xs:attribute name="face" type="xs:string"/>
        <xs:attribute name="color" type="xs:string"/>
      </xs:complexType>
    </xs:element>
    <xs:element name="img">
      <xs:complexType>
        <xs:attribute name="src" type="xs:string"/>
        <xs:attribute name="width" type="xs:decimal"/>
        <xs:attribute name="height" type="xs:decimal"/>
      </xs:complexType>
    </xs:element>
  </xs:group>
</xs:complexType>

</xs:schema>

Answer 1

Gaaah, curse you XML Schema!

Sorry, just need to let that out sometimes. I think this does what you want, but some testing wouldn’t be bad:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">

    <xs:element name="HTMLDocument">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="p" type="textElements" minOccurs="0" maxOccurs="unbounded"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:complexType name="textElements" mixed="true">
            <xs:group ref="textElementGroup" minOccurs="0" maxOccurs="unbounded"/>
    </xs:complexType>

    <xs:group name="textElementGroup">
        <xs:choice>
            <xs:element name="b" type="textElements" minOccurs="0" maxOccurs="1"/>
            <xs:element name="i" type="textElements" minOccurs="0" maxOccurs="1"/>
            <xs:element name="u" type="textElements" minOccurs="0" maxOccurs="1"/>
            <xs:element name="a" type="textElements" minOccurs="0" maxOccurs="1"/>
            <xs:element name="font" minOccurs="0" maxOccurs="1">
                <xs:complexType>
                    <xs:complexContent>
                        <xs:extension base="textElements">
                            <xs:attribute name="size" type="xs:string"/>
                            <xs:attribute name="face" type="xs:string"/>
                            <xs:attribute name="color" type="xs:string"/>
                        </xs:extension>
                    </xs:complexContent>
                </xs:complexType>
            </xs:element>
            <xs:element name="img" minOccurs="0" maxOccurs="1">
                <xs:complexType>
                    <xs:attribute name="src" type="xs:string"/>
                    <xs:attribute name="width" type="xs:decimal"/>
                    <xs:attribute name="height" type="xs:decimal"/>
                </xs:complexType>
            </xs:element>
        </xs:choice>
    </xs:group>

</xs:schema>

EDIT: oh, looks like you don’t need that extra xs:sequence. I’ll take it out…