Towards an XML document restructuring framework

Abstract: An XML documenthas a set of constraints associated, such as validity constraintsand cross-dependencies. When changing its structure theseconstraints must be maintained. In some cases a restructuringinvolves many dependent documents; such changes should be automatedto ensure consistency and efficiency.Most existing XML tools support simple updates, restricted to asingle document. Moreover, these tools often do not supportconcepts defined by a specific XML-application (an XML-applicationdefines the set of valid markup symbols, e.g., tags, and theirhierarchical structure). This work aims at developing a frameworkfor XML document restructuring. The framework facilitatesrealisation of document restructuring tools by providing advancedrestructuring functions, i.e., provide an environment whererestructuring operations can easily be realised. To avoidrestricting the framework to a specific set of XML-applications, itis designed for flexibility.The conceptual part of this work focuses on the definition of anoperation set for XML document restructuring, called the operationcatalogue. The operations are adapted to a document model definedby this work. The catalogue is divided into three abstractionlayers, corresponding to the concepts defined by XML,XML-applications, and XML-application policies. The layer structurefacilitates extensibility by allowing new operations to be definedin terms of existing. In the practical part, an architecture ispresented for a document restructuring framework which supportsrealisation of the earlier presented operations. The architectureis based on a layered approach to facilitate extensibility with newlayers that contain restructuring operations and functions for anXML-application or an XML-application policy. A new layer componentcan be added without recompilation of existing components. Toreduce resource consumption during document load and restructuringthe framework allows its user to specify, upon initialization, theset of active layer components (each layer component may performanalysis). This part also includes a prototype implementation ofthe presented architecture.This work results in an event-based framework for documentrestructuring that is extensible with restructuring support for newXML-application and XML-application policies. The framework is alsowell suited to manage inter document issues, such asdependencies.