Chapter 18 Working with XML

Reverse engineering an XML-DTD file

When you reverse engineer a DTD file into an OOM, you get a more readable view of the DTD. This feature can be very helpful when you want to check and understand a new DTD that you have not generated.

When you reverse engineer a DTD file into an OOM:

• Referenced DTD files, using DOCTYPE keyword, may not be reversed correctly, it is therefore better to choose a real DTD file rather than an XML document referencing a DTD file with a DOCTYPE document type declaration
• Elements of type #PCDATA are reversed as attributes
• An element that has both a parent and a child element is linked to its parent element by an aggregation link
• If an empty element has no child object but has attributes, it is reversed as a class and its attributes become attributes of the class
• Attributes of type ID and IDREF(S) are reversed as attributes with ID and IDREF(S) data types
• The attribute sequence order may not be preserved
• Attribute groups structure is not preserved
• DTD files may not be reversed properly if they contain some reference to an undefined parameter entity

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