A validation hook is some code written in Java™ notified by XXE before and after a document is checked for validity. A document is checked for validity on demand (menu item → ) but also automatically, after just being opened and before being saved to disk.
This mechanism has been created to perform semantic validation beyond what can be done using a DTD or schema.
A validation hook is declared in an XXE configuration file by the means of the
validateHook configuration element in . DITA topic example:
<validateHook name="checkTopicId"> <class>com.xmlmind.xmleditext.dita.CheckTopicId</class> </validateHook>
Invoked before a document conforming to a schema is validated.
Therefore validation hooks automatically fixing problems in the document being edited must implement method
Invoked after a document conforming to a DTD or schema has been validated.
Therefore validation hooks reporting semantic errors must implement method