Jean-Yves Vion-Dury

VXT: a visual approach to XML transformations

The domain of XML transformations is becoming more and more important as a result of the increasing number of applications adopting XML as their format for data exchange or representation. Most of the existing solutions for expressing XML transformations are textual languages, such as XSLT or DOM combined with a general-purpose programming language. Several tools build on top of these languages, providing a graphical environment. Transformations are however still specified in a textual way using the underlying language (often XSLT), thus requiring the user to learn the associated textual language.We believe that visual programming techniques are well-suited to representing XML structures and make the specification of transformations simpler. We present a visual programming language for the specification of XML transformations in an interactive environment, based on a zoomable user interface toolkit. Transformations can be run from the application or exported to two target languages: XSLT and Circus, a general-purpose structure transformation language designed by the second author and briefly introduced in this paper.

System services for distributed application configuration

The reuse of existing software components for the engineering of complex distributed applications is today a key issue in industrial development projects. Encapsulation and interconnection of heterogeneous legacy components have actually been raised as very fundamental issues and partial solutions have been proposed to overcome them such as the use of Object Request Brokers (ORB). However, these approaches do not address some of the issues raised by the construction of a complex distributed application from heterogeneous legacy components. This paper presents a set of configuration tools which intend to assist the application designer in the various stages of the application development life-cycle. This work has been carried out within the Olan project whose main result is an Architecture Definition Language for distributed application engineering and its runtime environment.

VXT: Visual XML Transformer

The ever-growing amount of heterogeneous data exchanged via the Internet, combined with the popularity of XML, makes structured document transformations an increasingly important application domain. Most of the existing solutions for expressing XML transformations are textual languages, such as XSLT (Extensible Stylesheet Language Transformations) or DOM (Document Object Model), combined with a general-purpose programming language. Several tools build on top of these languages, providing a graphical environment and debugging facilities. Transformations are, however, still specified in a textual way using the underlying language (often XSLT), thus requiring users to learn it. We believe that visual programming techniques are well-suited to representing XML structures and make the specification of transformations simpler. We propose a visual language, called VXT (Visual XML Transformer), for the specification of XML transformations in an interactive environment based on a zoomable user interface toolkit and on two target languages specialised in structure transformations: Circus and XSLT.

A Component Calculus for Modeling the Olan Configuration Language

Components will certainly become a key concept for the next generation of software architectures because of their impact on effective software reuse, real interoperability and integration. Within the Olan project [15], we face the difficulty of defining an operational semantics able to reflect the diversity of execution models involved in real applications. Existing process calculi offer the required abstractions such as encapsulation and process equivalences, but they rely on the fundamental assumption that agents are active, i.e autonomously able to initiate communication. However, components, viewed as software pieces with explicit interfaces, require a notion of passive composition that allows, for instance, several components to be traversed by a same process. In this paper, we introduce a calculus, named ICCS, which extends the Milners CCS calculus with (1) an operator for passive composition, and (2) selective interactions. While preserving the powerful theory of process equivalences established for CCS, this calculus provides an operational definition of passive components and allows thus to establish the basis of an operational semantics for the Olan Configuration Language.

A structured interactive workspace for a visual configuration language

The paper shows how language technologies such as the automatic generation of parsers for analyzing user actions and visual parsing can be applied to build a flexible tool specialized in complex specification tasks, namely the configuration of distributed applications. The central issue is to propose to structure the workspace through a syntax of user actions on one hand, and a syntax of visual representations on the other hand. From the tool designer side, this approach makes the core of the tool explicit through the grammar rules, and eases the generation of final code by simplifying verifications. From the user side, properties of the workspace generated from high level specifications increase the usability and improve the perception of the underlying semantics.

Experimenting with the circus language for XML modeling and transformation

After a brief introduction to the Circus programming language, we present a simple type set to model XML structures. We then describe a transformation that takes a mail as input and produces a reply, showing how subtyping is used in order to refine the type control and specialize the transformation. Conclusions are drawn both on our (easy to use but clearly limited) XML data model and on Circus itself ; expected qualities of the language are verified ; the need for some new features is expressed. Finally, we sketch some language extensions, a richer model for XML structures, and explain our choices and expectations.

A formal study of a visual language for the visualization of document type definition

This formal study proposes a transformational approach to the definition of general purpose visual languages based on hierarchical structures, addressing more specifically DTD visualization as its application area. We show that such visual languages can be constructed through progressive refinement of a syntax based on nested/juxtaposed rectangles. Several transformation stages, which can all be formally characterized, produce a high quality visual representation which expresses the fundamental properties of the original structure. Moreover, this approach opens some perspectives in proving visual properties through standard mathematical tools such as inductive proofs, thus establishing some practical links between visual language theory and classical language theory.

A generic calculus of XML editing deltas

In previous work we outlined a mathematical model of the so-called XML editing deltas and proposed a first study of their formal properties. We expected at least three outputs from this theoretical work: a common basis to compare performances of the various algorithms through a structural normalization of deltas, a universal and flexible patch application model and a clearer separation of patch and merge engine performance from delta generation performance. This paper presents the full calculus and reports significant progresses with respect to formalizing a normalization procedure. Such method is key to defining an equivalence relation between editing scripts and eventually designing optimizers compiler back-ends, new patch specification languages and execution models.

Multi-Context Systems for Consistency Validation and Querying of Business Process Models

Large organizations today face a growing challenge of managing heterogeneous process collections containing business processes. Explicit semantics inherent to domain-specific models can help alleviate some of the management challenges. Starting with concept definitions, designers can create domain specific processes and eventually generate industry-standard BPMN for use in BPMS solutions. However, in such a multi-layered setting, any of these artefacts (concepts, domain processes and BPMN) can be modified by various stakeholders and changes done by one person may influence models used by others. There is therefore a need for tool support to aid in keeping track of changes done and their impacts on different stakeholders. In this paper, we present a multi-context systems based approach that allows inferring impacts of changes, especially in terms of consistency, and executing semantic queries. In contrast to existing work, our framework allows the co-existence of different formalisms, with potentially different characteristics, offering greater flexibility in knowledge base and tool integration.

Preserving Consistency in Domain-Specific Business Processes Through Semantic Representation of Artefacts

Large organizations today face a growing challenge of managing heterogeneous process collections containing business processes. Explicit semantics inherent to domain-specific models can help alleviate some of the management challenges. Starting with concept definitions, designers can create domain specific processes and eventually generate industry-standard BPMN for use in BPMS solutions. However, any of these artefacts (concepts, domain processes and BPMN) can be modified by various stakeholders and changes done by one person may influence models used by others. There is therefore a need for tool support to aid in keeping track of changes done and their impacts on different stakeholders. In this paper we present an approach towards providing such support based on a semantic layer that records the provenance of the information and accordingly propagates impacts of changes to related resources, and illustrate the applicability of the approach via an illustrative example.