Enhanced Control using Fine-Grain Validation

["Costello, Roger L." <costello@mitre.org>]

Hi Folks,

When an XML instance document is validated against an XML Schema, the validator returns valid or invalid. If invalid is returned, the XML document is rejected. If valid is returned, the XML document is accepted and processed. The decision to process inputs is made on a per-document basis. That course-grain, all-or-nothing approach to accepting and processing inputs is very limiting. Suppose, for example, that the XML document contains data for 1000 Books and all the Books are valid except one. Rejecting the entire document because of one bad Book is terribly inefficient.

I wrote a paper that shows how to validate -- in an automated fashion -- each item of an XML document and make validation decisions on a per-item basis rather than a per-document basis. The items to be validated may be as fine-grain or as course-grain as desired: the item may be a single element (or even just the text within a leaf element) or the item may be an element composed of many descendent elements. Validation may be done from the outside in (the root element to the leaf nodes) or the inside out (the leaf nodes to the root element). 

I call the technique presented in the paper: fine-grain validation.

By using the technique, your XML Schemas change from being a large template that XML documents must conform to, to a collection of rules from which we can pick and choose.

Here is the paper: http://www.xfront.com/Fine-Grain-Validation.pdf

/Roger