Based on schema logic, and at first blush, I think your second assertion
is correct. A schema specifies what specific elements must contain, but
not which elements must contain THEM. In other words, the schema
validator looks down the tree, but not up or across the tree.
As a quick and dirty test, I created the following schema in oXygen:
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema";>
<xs:element name="root">
<xs:complexType>
<xs:sequence>
<xs:element ref="child" minOccurs="1"/>
<xs:element ref="child2" minOccurs="1"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="child"/>
<xs:element name="child2"/>
</xs:schema>
Then, I created the following instance document:
<?xml version="1.0" encoding="UTF-8"?>
<child xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
xsi:noNamespaceSchemaLocation="file:/C:/Documents%20and%20Settings/cmullin/My%20Documents/text.xsd"/>
Though the "root" element of my instance document (<child>) is defined
as a required child element of <root>, there are no "down-tree"
requirements for <child>. Thus, the document is valid with only <child>.
Bear in mind that this experiment was based on only the simplest of
examples. Is there something I'm missing? I look forward to other
responses...
Hope this has helped,
Casey
Jonathan Rochkind wrote:
Anyone familiar with XML schemas (.xsd)?
Can you help me figure something out. Is there something in the schema
that specifies what elements can serve as the 'root node'... or is any
element described in the schema avaialable for use as a 'root node',
and it'll still validate?
Thanks for any tips.
Jonathan
--
Casey A. Mullin
Discovery Metadata Librarian
Metadata Development Unit
Stanford University Libraries
650-736-0849
[email protected]
http://www.caseymullin.com
