Jesús Sánchez Cuadrado

RubyTL: a practical, extensible transformation language

Model transformation is a key technology of model driven development approaches. A lot of research therefore is being carried out to understand the nature of model transformations and find out desirable characteristics of transformation languages. In recent years, several transformation languages have been proposed. We present the RubyTL transformation language which has been designed as an extensible language–a set of core features along with an extension mechanism. RubyTL provides a framework for experimenting with features of hybrid transformation languages. In addition, RubyTL has been created as a domain specific language embedded in the Ruby programming language. In this paper we show the core features of the language through a simple example and explain how the language can be extended to provide more features.

A research roadmap towards achieving scalability in model driven engineering

As Model-Driven Engineering (MDE) is increasingly applied to larger and more complex systems, the current generation of modelling and model management technologies are being pushed to their limits in terms of capacity and efficiency. Additional research and development is imperative in order to enable MDE to remain relevant with industrial practice and to continue delivering its widely recognised productivity, quality, and maintainability benefits. Achieving scalability in modelling and MDE involves being able to construct large models and domain-specific languages in a systematic manner, enabling teams of modellers to construct and refine large models in a collaborative manner, advancing the state of the art in model querying and transformations tools so that they can cope with large models (of the scale of millions of model elements), and providing an infrastructure for efficient storage, indexing and retrieval of large models. This paper attempts to provide a research roadmap for these aspects of scalability in MDE and outline directions for work in this emerging research area.

When and How to Use Multilevel Modelling

Model-Driven Engineering (MDE) promotes models as the primary artefacts in the software development process, from which code for the final application is derived. Standard approaches to MDE (like those based on MOF or EMF) advocate a two-level metamodelling setting where Domain-Specific Modelling Languages (DSMLs) are defined through a metamodel that is instantiated to build models at the metalevel below. Multilevel modelling (also called deep metamodelling) extends the standard approach to metamodelling by enabling modelling at an arbitrary number of metalevels, not necessarily two. Proposers of multilevel modelling claim this leads to simpler model descriptions in some situations, although its applicability has been scarcely evaluated. Thus, practitioners may find it difficult to discern when to use it and how to implement multilevel solutions in practice. In this article, we discuss those situations where the use of multilevel modelling is beneficial, and identify recurring patterns and idioms. Moreover, in order to assess how often the identified patterns arise in practice, we have analysed a wide range of existing two-level DSMLs from different sources and domains, to detect when their elements could be rearranged in more than two metalevels. The results show this scenario is not uncommon, while in some application domains (like software architecture and enterprise/process modelling) pervasive, with a high average number of pattern occurrences per metamodel.

A Model-Based Approach to Families of Embedded Domain-Specific Languages

With the emergence of model-driven engineering (MDE), the creation of domain-specific languages (DSLs) is becoming a fundamental part of language engineering. The development cost of a DSL should be modest compared to the cost of developing a general-purpose programming language. Reducing the implementation effort and providing reuse techniques are key aspects for DSL approaches to be really effective. In this paper, we present an approach to build embedded domain-specific languages applying the principles of model-driven engineering. On the basis of this approach, we will tackle reuse of DSLs by defining families of DSLs, addressing reuse both from the DSL developer and user point of views. A family of DSLs will be built up by composing several DSLs, so we will propose composition mechanisms for the abstract syntax, concrete syntax, and model transformation levels of a DSLs definition. Finally, we contribute a software framework to support our approach, and we illustrate the paper with a case study to demonstrate its practical applicability.

Generic model transformations: write once, reuse everywhere

Model transformation is one of the core techniques in Model Driven Engineering. Many transformation languages exist nowadays, but few offer mechanisms directed to the reuse of whole transformations or transformation fragments in different contexts. Taking inspiration from generic programming, in this paper we define model transformation templates. These templates are defined over metamodel concepts which later can be bound to specific meta-models. The binding mechanism is flexible as it permits mapping concepts and metamodels with certain kinds of structural heterogeneities. The approach is general and can be applied to any model transformation language. In this paper we report on its application to ATL.

A Component Model for Model Transformations

Model-driven engineering promotes an active use of models to conduct the software development process. In this way, models are used to specify, simulate, verify, test and generate code for the final systems. Model transformations are key enablers for this approach, being used to manipulate instance models of a certain modelling language. However, while other development paradigms make available techniques to increase productivity through reutilization, there are few proposals for the reuse of model transformations across different modelling languages. As a result, transformations have to be developed from scratch even if other similar ones exist. In this paper, we propose a technique for the flexible reutilization of model transformations. Our proposal is based on generic programming for the definition and instantiation of transformation templates, and on component-based development for the encapsulation and composition of transformations. We have designed a component model for model transformations, supported by an implementation currently targeting the Atlas Transformation Language (ATL). To evaluate its reusability potential, we report on a generic transformation component to analyse workflow models through their transformation into Petri nets, which we have reused for eight workflow languages, including UML Activity Diagrams, YAWL and two versions of BPMN.

Example-driven meta-model development

The intensive use of models in model-driven engineering (MDE) raises the need to develop meta-models with different aims, such as the construction of textual and visual modelling languages and the specification of source and target ends of model-to-model transformations. While domain experts have the knowledge about the concepts of the domain, they usually lack the skills to build meta-models. Moreover, meta-models typically need to be tailored according to their future usage and specific implementation platform, which demands knowledge available only to engineers with great expertise in specific MDE platforms. These issues hinder a wider adoption of MDE both by domain experts and software engineers. In order to alleviate this situation, we propose an interactive, iterative approach to meta-model construction, enabling the specification of example model fragments by domain experts, with the possibility of using informal drawing tools like Dia or yED. These fragments can be annotated with hints about the intention or needs for certain elements. A meta-model is then automatically induced, which can be refactored in an interactive way, and then compiled into an implementation meta-model using profiles and patterns for different platforms and purposes. Our approach includes the use of a virtual assistant, which provides suggestions for improving the meta-model based on well-known refactorings, and a validation mode, enabling the validation of the meta-model by means of examples.

Modularization of model transformations through a phasing mechanism

In recent years a great effort has been devoted to understanding the nature of model transformations. As a result, several mechanisms to improve model transformation languages have been proposed. Phasing has been mentioned in some works as a rule scheduling or organization mechanism, but without any detail. In this paper, we present a phasing mechanism in the context of rule-based transformation languages. We explain the structure and the behavior of the mechanism, and how it can be integrated in a language. We also analyze how the mechanism promotes modularity, internal transformation composition and helps to solve usual transformation problems. Besides, we show several examples of application to illustrate the usefulness of the mechanism.

Model-driven reverse engineering of legacy graphical user interfaces

Businesses are more and more modernizing the legacy systems they developed with Rapid Application Development (RAD), so that they can benefit from the new platforms and technologies. In these systems, the Graphical User Interface (GUI) layout is implicitly given by the position of the GUI elements (i.e. coordinates). However, taking advantage of current features of GUI technologies often requires an explicit, high-level layout model. We propose a Model-Driven Engineering process to perform reverse engineering of RAD-built GUIs, which is focused on discovering the implicit layout, and produces a GUI model where the layout is explicit. Based on the information we obtain, other reengineering activities can be performed, for example, to adapt the GUI for mobile device screens.

Approaches for Model Transformation Reuse: Factorization and Composition

Reusability is one of the principal software quality factors. In the context of model driven development (MDD), reuse of model transformations is also considered a key activity to achieve productivity and quality. It is necessary to devote important research efforts to find out appropriate reusability mechanisms for transformation tools and languages. In this paper we present two approaches for reusing model transformation definitions. Firstly, we tackle the creation of related model transformations, showing how the factorization of common parts can be achieved. Secondly, we describe a proposal on the composition of existing, separated transformation definitions so that they can be used to solve a concrete transformation problem. We illustrate both proposals with examples taken from the development of a software product line for adventure games, which has been implemented using the modularization mechanisms of the RubyTL transformation language.