xsd - Recursion in an XML schema?

Question

I need to create an XML schema that validates a tree structure of an XML document. I don't know exactly the occurrences or depth level of the tree.

XML example:

<?xml version="1.0" encoding="utf-8"?>
<node>
  <attribute/>
  <node>
    <attribute/>
    <node/>      
  </node>
</node> 

Which is the best way to validate it? Recursion?

Answer 1

if you need a recursive type declaration, here is an example that might help:

<xs:schema id="XMLSchema1"
    targetNamespace="http://tempuri.org/XMLSchema1.xsd"
    elementFormDefault="qualified"
    xmlns="http://tempuri.org/XMLSchema1.xsd"
    xmlns:mstns="http://tempuri.org/XMLSchema1.xsd"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
>
  <xs:element name="node" type="nodeType"></xs:element>

  <xs:complexType name="nodeType">    
    <xs:sequence minOccurs="0" maxOccurs="unbounded">
      <xs:element name="node" type="nodeType"></xs:element>
    </xs:sequence>
  </xs:complexType>

</xs:schema>

As you can see, this defines a recursive schema with only one node named "node" which can be as deep as desired.