Document Structure Description
Document Structure Description or DSD is a schema language that is used to describe classes of XML documents, which all have the same syntactic requirements for its structure and content. DSD was developed in cooperation with BRICS and AT & T Labs Research.
Development Goals
The development goals of DSD were:
- To contain few and simple -to-understand language components (on Boolean logic and regular expressions based ) and
- Also for non-XML experts easy to understand
- To be more expressive than other document type definition languages , for most practical purposes
Concepts
The central concept of DSD is that each DSD schema consists of a list of rules. A validating XML parser has to process all the rules for all elements of an XML document. The rules contained here declare and require sections. Declare sections define what content ( sub-elements and character data ) and which attributes for the element are allowed. Require - sections define extended restrictions on content and attributes. This rule conditions and extended constraints are described by Boolean logic, while the values of the attributes and contents of the elements are described by regular expressions.
Example
An example of a DSD:
< dsd xmlns = " http://www.brics.dk/DSD/2.0 "
xmlns: my = " http://example.com " >
An XML document with respect to the above listed DSD specification would be valid, would be for example:
- Document Structure Description 2.0 specification ( English)
- DSD 2.0 of the authors explained (English)