making reference to other elements...

[Pablo Gomes Ludermir]

Hello,

I have the following case that I am trying to put in XML Schema.
I have the classes HelpItem, Document and Message that work as follows:

One HelpItem contains several Document and Message instances.
Thus, in XML Document and Message are child elements of HelpItem.

However, a Message may have a reference to one or several existing
Docuemnt instances, and also may have a reference to one or several
Message instances (its replies) and another Message that it is the
parent Message (the Message that I am replying to).

How can I make the references to the documents and other messages (I
hope that the reference to the messages is correct in the example bellow)?

The following information is to keep it more clear:

class Message
- referencedDocuments List
- conversation List //messages that reply the current one (optional)
- parentMessage Message //the message that I am replying to
end class

<xs:element name="Document" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="id" type="xs:ID" use="required"/>
... other attributes here
</xs:complexType>
</xs:element>


<xs:element name="Message" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="id" type="xs:ID" use="required"/>
<xs:attribute name="parentMessage" type="xs:IDREF" use="optional"/>
<xs:attribute name="conversation" type="xs:IDREFS" use="optional"/>
... other attributes here
</xs:complexType>
</xs:element>

 

[Martin Honnen]

Pablo Gomes Ludermir wrote:

I have the following case that I am trying to put in XML Schema.
I have the classes HelpItem, Document and Message that work as follows:

One HelpItem contains several Document and Message instances.
Thus, in XML Document and Message are child elements of HelpItem.

However, a Message may have a reference to one or several existing
Docuemnt instances, and also may have a reference to one or several
Message instances (its replies) and another Message that it is the
parent Message (the Message that I am replying to).

How can I make the references to the documents and other messages (I
hope that the reference to the messages is correct in the example bellow)?

The following information is to keep it more clear:

class Message
- referencedDocuments List
- conversation List //messages that reply the current one (optional)
- parentMessage Message //the message that I am replying to
end class

<xs:element name="Document" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="id" type="xs:ID" use="required"/>
... other attributes here
</xs:complexType>
</xs:element>


<xs:element name="Message" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="id" type="xs:ID" use="required"/>
<xs:attribute name="parentMessage" type="xs:IDREF" use="optional"/>
<xs:attribute name="conversation" type="xs:IDREFS" use="optional"/>
... other attributes here
</xs:complexType>
</xs:element>

On a first look your use of xs:ID and xs:IDREF and xs:IDREFS seems fine
to me. Or are you getting any error messages from a schema processor?

 

[Pablo Gomes Ludermir]

Well, XMLSpy did not make any complaints. But the point was that I don't
know how to figure out the reference from the message to the document
element.
And another thing is that the ID is not on the local scope of the
element, but of the whole document. Is there a way to keep the ID unique
on the scope of the element?

Regards,
Pablo

 

[Martin Honnen]

Pablo Gomes Ludermir wrote:

And another thing is that the ID is not on the local scope of the
element, but of the whole document. Is there a way to keep the ID unique
on the scope of the element?

xs:ID needs to be unique inside of the complete document but you can use
xs:key to define keys in the scope of an element, see the example in
http://www.w3.org/TR/xmlschema-0/#specifyingKeysAndtheirRefs