Changes in an XML document may affect not only element and attribute content but, more problematically, the markup hierarchy. Markup for tracking structural changes must represent multiple, often overlapping, structures in the same document. Thus, the perennial problem of overlap becomes a subset of the problem of managing change to structured documents, such as versions of documents amended over time.
We have developed changes to the delta file. This new representation allows us to define overlapping hierarchies in a completely XML way without declaring a dominant hierarchy and while keeping element fragmentation to a minimum.
Read this conference paper to:
Understand the difficulties associated with representing change with overlapping hierarchies.
Review how this change can be represented in a way that’s easily understood.
Learn how we overcame the need for duplication when finding overlapping hierarchy change.
Learn how changes to attributes can also be represented.
Representing Overlapping Hierarchy as Change in XML
This paper describes a new representation for overlapping hierarchy in XML. In addition to handling variants of the structure of an XML document, this representation handles changes to text and attributes.
Software developers are familiar with merge, e.g., pulling together changes from one branch into another in a version control system. Graft is a more selective process, pulling changes from selected commits onto another branch. These two processes are often implemented in the same way, but there are important differences between the two that needs addressing.