A Graph-Based Approach to Transform XML Documents

As XML diffusion keeps increasing, it is today common practice for most developers to deal with XML parsing and transformation. XML is used as format to e.g. render data, query documents, deal with Web services, generate code from a model or perform model transformation. Nowadays XSLT is the most common language for XML transformation. But, although meant to be simple, coding in XSLT can become quite a challenge, if the coding approach does not only depend on the structure of the source document, but the order of template application is also dictated by target document structure. This is the case especially when dealing with transformations between visual models. We propose to use a graph-based approach to simplify the transformation definition process where graphs representing documents are transformed in a rule-based manner, as in XSLT. The differences to XSLT are mainly that rules can be developed visually, are more abstract (since the order of execution does not depend on the target document), IDREFs are dealt with much more naturally, and due to typed transformations, the output document is guaranteed to be valid with respect to the target schema. Moreover, graph-based transformation definitions can be automatically reversed in most cases. This is especially useful in model transformation (e.g. in OMG’s MDA approach).