Performs validation on the page elements. Attributes are checked for
mandatory presence, entry value validity, and consistency. As a side effect,
some page global value (such as those from page direcitves) are stored, for
later use.
author: Kin-man Chung author: Jan Luehe author: Shawn Bayern author: Mark Roth
Inner Class :static class DirectiveVisitor extends Node.Visitor
Inner Class :static class ValidateVisitor extends Node.Visitor
Inner Class :static class TagExtraInfoVisitor extends Node.Visitor