The XML schema editor has a built-in mechanism to handle referential
integrity issues. When you delete certain nodes, clean up for any nodes affected
will automatically occur.
When you define a complex type, you can add a content model to it
and reference a global element.
For example:
<schema>
<element name="comment" type="string">
<complexType name="Items">
<sequence>
<element ref="comment">
</sequence>
</complexType>
</schema>
If the global element (comment) was deleted,
all references to it would be in error. However, when you delete the global
element, the XML schema editor will clean up using the following algorithm:
- If there are one or more global elements in the schema, it will change
all existing references to the first global element.
- If there is no global element, then it will delete the element reference
from the content model.