A cleaner way of writing an XSD document

Is there a cleaner way of writing a XSD document. I find that the code is very difficult to read whene there is lots of attributes and extended elements. This is my XSD example:

I added a few restriction on attributes.

?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="footballGame">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="game">
          <xs:complexType>
            <xs:sequence>
              <xs:element name="team" minOccurs="2" maxOccurs="2">
                <xs:complexType>
                  <xs:sequence>
                  <xs:element name="teamName" type="xs:string"/>
                  <xs:element name="goal" minOccurs="0" maxOccurs="unbounded">
                    <xs:complexType>
                      <xs:sequence>
                        <xs:element name="playerName" type="xs:string"/>
                        <xs:element name="goalMinute">
                          <xs:simpleType>
                            <xs:restriction base="xs:string">
                              <xs:length value="2"/>
                            </xs:restriction>
                          </xs:simpleType>
                        </xs:element>
                      </xs:sequence> 
                    <xs:attribute name="penalty" use="required">
                      <xs:simpleType>
                        <xs:restriction base="xs:string">
                          <xs:enumeration value="yes"/>
                          <xs:enumeration value="no"/> 
                        </xs:restriction>
                      </xs:simpleType>
                    </xs:attribute>
                    </xs:complexType> 
                  </xs:element>
                  <xs:element name="card" minOccurs="0" maxOccurs="unbounded">
                  <xs:complexType>
                  <xs:sequence>
                    <xs:element name="playerNmae" type="xs:string"/>
                    <xs:element name="cardType">
                     <xs:complexType>
                      <xs:attribute name="card"> 
                        <xs:simpleType>
                          <xs:restriction base="xs:string">
                            <xs:enumeration value="yellow"/>
                            <xs:enumeration value="red"/>
                          </xs:restriction> 
                        </xs:simpleType>
                      </xs:attribute>
                     </xs:complexType> 
                    </xs:element>
                    <xs:element name="cardMinute" type="xs:positiveInteger"/>
                </xs:sequence>              
              </xs:complexType>                  
                  </xs:element>
                  </xs:sequence>
                  <xs:attribute name="homeOrAway" use="required">
                    <xs:simpleType>
                      <xs:restriction base="xs:string">
                        <xs:enumeration value="home"/>
                        <xs:enumeration value="away"/> 
                      </xs:restriction> 
                    </xs:simpleType> 
                  </xs:attribute>
                </xs:complexType> 
              </xs:element> 
            </xs:sequence> 
          </xs:complexType> 
        </xs:element> 
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

I tried putting attributes to the end of code, but dont know how to reference them.

Solution

You could define the types for your element and attributes separately, and then declare that elements and attributes are of that type:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="footballGame" type="footballGame" />
       
    <xs:complexType name="footballGame">
        <xs:sequence>
            <xs:element type="game" name="game" />
        </xs:sequence>
    </xs:complexType>
    
    <xs:complexType name="game">
        <xs:sequence>
            <xs:element type="team" name="team" minOccurs="2" maxOccurs="2"/>
        </xs:sequence> 
    </xs:complexType>
    
    <xs:complexType name="team">
        <xs:sequence>
            <xs:element name="teamName" type="xs:string"/>
            <xs:element type="goal" name="goal" minOccurs="0" maxOccurs="unbounded" />
            <xs:element type="card" name="card" minOccurs="0" maxOccurs="unbounded"/>
        </xs:sequence>
        <xs:attribute type="homeOrAway" name="homeOrAway" use="required" />
    </xs:complexType>
    
    <xs:simpleType name="homeOrAway">
        <xs:restriction base="xs:string">
            <xs:enumeration value="home"/>
            <xs:enumeration value="away"/> 
        </xs:restriction> 
    </xs:simpleType>
    
    <xs:complexType name="goal">
        <xs:sequence>
            <xs:element name="playerName" type="xs:string"/>
            <xs:element type="minute" name="goalMinute" />
        </xs:sequence> 
        <xs:attribute type="penalty" name="penalty" use="required"/>
    </xs:complexType>
    
    <xs:simpleType name="minute">
        <xs:restriction base="xs:string">
            <xs:length value="2"/>
        </xs:restriction>
    </xs:simpleType>
    
    <xs:simpleType name="penalty">
        <xs:restriction base="xs:string">
            <xs:enumeration value="yes"/>
            <xs:enumeration value="no"/> 
        </xs:restriction>
    </xs:simpleType>
    
    <xs:complexType name="card">
        <xs:sequence>
            <xs:element name="playerNmae" type="xs:string"/>
            <xs:element name="cardType">
                <xs:complexType>
                    <xs:attribute name="card"> 
                        <xs:simpleType>
                            <xs:restriction base="xs:string">
                                <xs:enumeration value="yellow"/>
                                <xs:enumeration value="red"/>
                            </xs:restriction> 
                        </xs:simpleType>
                    </xs:attribute>
                </xs:complexType> 
            </xs:element>
            <xs:element name="cardMinute" type="xs:positiveInteger"/>
        </xs:sequence>              
    </xs:complexType>
    
</xs:schema>

A cleaner way of writing an XSD document

See also