An XML document has a set of constraints associated, such as validity constraints and cross-dependencies. When changing its structure these constraints must be maintained. In some cases a restructuring involves many dependent documents; such changes should be automated to ensure consistency and efficiency.
Most existing XML tools support simple updates, restricted to a single document. Moreover, these tools often do not support concepts defined by a specific XML-application (an XML-application defines the set of valid markup symbols, e.g., tags, and their hierarchical structure). This work aims at developing a framework for XML document restructuring. The framework facilitates realisation of document restructuring tools by providing advanced restructuring functions, i.e., provide an environment where restructuring operations can easily be realised. To avoid restricting the framework to a specific set of XML-applications, it is designed for flexibility.
The conceptual part of this work focuses on the definition of an operation set for XML document restructuring, called the operation catalogue. The operations are adapted to a document model defined by this work. The catalogue is divided into three abstraction layers, corresponding to the concepts defined by XML, XML-applications, and XML-application policies. The layer structure facilitates extensibility by allowing new operations to be defined in terms of existing.
In the practical part, an architecture is presented for a document restructuring framework which supports realisation of the earlier presented operations. The architecture is based on a layered approach to facilitate extensibility with new layers that contain restructuring operations and functions for an XML-application or an XML-application policy. A new layer component can be added without recompilation of existing components. To reduce resource consumption during document load and restructuring the framework allows its user to specify, upon initialization, the set of active layer components (each layer component may perform analysis). This part also includes a prototype implementation of the presented architecture.
This work results in an event-based framework for document restructuring that is extensible with restructuring support for new XML-application and XML-application policies. The framework is also well suited to manage inter document issues, such as dependencies.
Linköping: Linköpings universitet , 2007. , 128 p.
2007-02-12, Alan Turing, Hus E, Linköpings universitet, Linköping, 10:15 (Swedish)