RE: question about group circle definition

I see :-) 

I’m very appreciated your exact explanation! 

The group reference is inside the complexType which limits the particle element “ul”. 

So, the reference not belongs to the particles inside the group. 

 

-Wang Zhuo 

________________________________

From: Michael Kay [mailto:mike@saxonica.com] 
Sent: 2007年3月8日 18:00
To: Wang, Zhuo; xmlschema-dev@w3.org
Cc: Moog, Thomas H
Subject: RE: question about group circle definition 

 

The reason is that the group reference is not "within the model group at any depth", because it's in a different complexType:

 

    <xsd:group name="ul">
        <xsd:sequence>
            <xsd:element name="ul">
                <xsd:complexType>
                    <xsd:sequence>
                        <xsd:choice minOccurs="0" maxOccurs="unbounded">
                            <xsd:element name="li" /> 
                            <xsd:group ref="ul" minOccurs="0" maxOccurs="unbounded" /> 
                        </xsd:choice>
                    </xsd:sequence>
                </xsd:complexType>
            </xsd:element>
        </xsd:sequence>
    </xsd:group>

 

The constraint is on the schema component model, not the XML representation, and the schema component model is the same as if it had been written:

 

    <xsd:group name="ul">
        <xsd:sequence>
            <xsd:element name="ul" type="anonZZZ"/>
        </xsd:sequence>
    </xsd:group>

 

                <xsd:complexType name="anonZZZ">
                    <xsd:sequence>
                        <xsd:choice minOccurs="0" maxOccurs="unbounded">
                            <xsd:element name="li" /> 
                            <xsd:group ref="ul" minOccurs="0" maxOccurs="unbounded" /> 
                        </xsd:choice>
                    </xsd:sequence>
                </xsd:complexType>

which makes it clear that the group does not actually contain a reference to itself.

 

Michael Kay

http://www.saxonica.com/


  

 
________________________________


 From: xmlschema-dev-request@w3.org [mailto:xmlschema-dev-request@w3.org] On Behalf Of Wang, Zhuo
 Sent: 08 March 2007 08:39
 To: Michael Kay; xmlschema-dev@w3.org
 Cc: Moog, Thomas H
 Subject: RE: question about group circle definition 

 The case is: 

 /xmlschema2006-11-06/msData/particles/particlesZ010.xsd

  

 Thanks, 

 -Wang Zhuo 

 
________________________________


 From: Michael Kay [mailto:mike@saxonica.com] 
 Sent: 2007年3月8日 16:38
 To: Wang, Zhuo; xmlschema-dev@w3.org
 Cc: Moog, Thomas H
 Subject: RE: question about group circle definition 

  

 Could you give the name of the test case please?

  

 Michael Kay

 http://www.saxonica.com/

   

  
________________________________


  From: xmlschema-dev-request@w3.org [mailto:xmlschema-dev-request@w3.org] On Behalf Of Wang, Zhuo
  Sent: 08 March 2007 01:31
  To: xmlschema-dev@w3.org
  Cc: Moog, Thomas H
  Subject: question about group circle definition 

  Hi All, 

   

  I meet a case in w3c test suite: 

   

  <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">

   

      <xsd:complexType name="a">

          <xsd:sequence>

              <xsd:group ref="ul" minOccurs="0" maxOccurs="unbounded"/> 

          </xsd:sequence>

      </xsd:complexType> 

   

      <xsd:group name="ul">

          <xsd:sequence>

              <xsd:element name="ul">

                  <xsd:complexType>

                      <xsd:sequence>

                          <xsd:choice minOccurs="0" maxOccurs="unbounded">

                              <xsd:element name="li" /> 

                              <xsd:group ref="ul" minOccurs="0" maxOccurs="unbounded" /> 

                          </xsd:choice>

                      </xsd:sequence>

                  </xsd:complexType>

              </xsd:element>

          </xsd:sequence>

      </xsd:group>

   

  </xsd:schema>

   

  I think this case voilate:

  3.8.6 Constraints on Model Group Schema Components

  All model groups (see Model Groups (¡ì3.8)) must satisfy the following

  constraints.

   

  Schema Component Constraint: Model Group Correct

  All of the following must be true:

  2 Circular groups are disallowed. That is, within the {particles} of a group

  there must not be at any depth a particle whose {term} is the group itself.

   

  However, many schema validators say it is a valid case. 

  Somebody knows the reason? 

   

  Thanks, 

  - Wang Zhuo    

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