Dongxi Liu

Towards automatic model synchronization from model transformations

The metamodel techniques and model transformation techniques provide a standard way to represent and transform data, especially the software artifacts in software development. However, after a transformation is applied, the source model and the target model usually co-exist and evolve independently. How to propagate modifications across models in different formats still remains as an open problem.n In this paper we propose an automatic approach to synchronizing models that are related by model transformations. Given a unidirectional transformation between metamodels, we can automatically synchronize models in the metamodels by propagating modifications across the models. We have implemented a model synchronization system supporting the Atlas Transformation Language (ATL) and have successfully tested our implementation on several ATL transformation examples in the ATL web site.

Bidirectional interpretation of XQuery

XQuery is a powerful functional language to query XML data. This paper gives a bidirectional interpretation of XQuery to address the problem of updating XML data through materialized XQuery views. We first design an expressive bidirectional transformation language, and then translate XQuery expressions into the code of this language. As a result, an XQuery expression can execute in two directions: in the forward direction, it generates a materialized view from the source XML data; while in the backward direction, it updates the source data by putting back the updates on the view. we have implemented our approach and applied it to some XQuery use cases from a W3C draft, which confirms the practicability of this approach.

A web service architecture for bidirectional XML updating

A Web service architecture is described for bidirectional XML updating. The updating mechanism exploits the power of bidirectional transformation so that users can update remote XML data by editing a view on the local machine that is generated by a transformation of the XML data. This architecture consists of three tiers: data viewer clients, a bidirectional transformation engine, and content servers accessible through the Internet. Due to the use of standard Web service technologies, the data viewer clients and content servers can be easily replaced with ones chosen by the user. Users can use this architecture to implement their own applications that exploit the power of bidirectional transformation without the burden of installing and maintaining a bidirectional language package.

An environment for maintaining computation dependency in XML documents

In the domain of XML authoring, there have been many tools to help users to edit XML documents. These tools make it easier to produce complex documents by using such technologies as syntax-directed or presentation-oriented editing, etc. However, when an XML document contains data with some computation dependency among them, these tools cannot free users from the burden of maintaining this dependency relationship. By computation dependency, we mean that some data are gotten by computing from other data in the same document.In this paper, we present an environment for authoring XML document, in which users can express the data dependency relationship in one document explicitly rather than implicitly in their minds. Under this environment, the dependent parts of the document are represented as expressions, which in turn can be evaluated to generate the dependent data. Therefore, users need not to compute the dependent data first and then input them manually, as required by the current authoring tools.