Alexandre de Spindler

Dynamic metamodel extension modules to support adaptive data management

Databases are now used in a wide variety of settings resulting in requirements which may differ substantially from one application to another, even to the point of conflict. Consequently, there is no database product that can support all forms of information systems ranging from enterprise applications to personal information systems running on mobile devices. Further, domains such as the Web have demonstrated the need to cope with rapidly evolving requirements. We define dynamic metamodel extension modules that support adaptive data management by evolving a system in the event of changing requirements and show how this technique was applied to cater for specific application settings.

Development Framework for Mobile Social Applications

Developments in mobile phone technologies have opened the way for a new generation of mobile social applications that allow users to interact and share information. However, current programming platforms for mobile phones provide limited support for information management and sharing, requiring developers to deal with low-level issues of data persistence, data exchange and vicinity sensing. We present a framework designed to support the requirements of mobile social applications based on a notion of P2P data collections and a flexible event model that controls how and when data is exchanged. We show how the framework can be used by describing the development of a mobile application for collaborative filtering based on opportunistic information sharing.

Information Sharing Modalities for Mobile Ad-Hoc Networks

Current mobile phone technologies have fostered the emergence of a new generation of mobile applications. Such applications allow users to interact and share information opportunistically when their mobile devices are in physical proximity or close to fixed installations. It has been shown how mobile applications such as collaborative filtering and location-based services can take advantage of ad-hoc connectivity to use physical proximity as a filter mechanism inherent to the application logic. We discuss the different modes of information sharing that arise in such settings based on the models of persistence and synchronisation. We present a platform that supports the development of applications that can exploit these modes of ad-hoc information sharing and, by means of an example, show how such an application can be realised based on the supported event model.

Recommendation Based on Opportunistic Information Sharing Between Tourists

We propose a new approach to collaborative filtering in mobile tourist information systems based on spatio-temporal proximity in social contexts. The approach is motivated by a survey of festival visitors confirming that similarities of interests extends beyond events defining specific social contexts. We show how opportunistic information sharing in mobile ad-hoc networks can be used to realise decentralised collaborative filtering appropriate for mobile environments and show its equivalence to existing centralised approaches. Mobile Information System, Spatio-Temporal Proximity, Copresence, Social Context, Opportunistic Sharing, Ad-hoc Networks, Collaborative Filtering

Integrating component-based web engineering into content management systems

Popular content management systems such as WordPress and Drupal offer a plug-in mechanism that allows users to extend the platform with additional functionality. However, plug-ins are typically isolated extensions defining their own data structures, application logic and user interface, and are difficult to combine. We address the fact that users may want to configure their applications more freely through the composition of such extensions. We present an approach and model for component-based web engineering based on the concept of components and connectors between them, supporting composition at the level of the schema and data, the application logic and the user interface. We show how our approach can be used to integrate component-based web engineering into platforms such as WordPress. We demonstrate the benefits of the approach by presenting a composition plug-in that showcases component composition through configurable connectors based on an eCommerce application scenario.

A meta-plugin for bespoke data management in wordpress

WordPress is a powerful and extensible platform for web-based information publishing and management. While the WordPress core is targeted to the publication of chronologically ordered textual articles typical of blogs, users have developed plugins as well as themes to support the data management requirements of specific domains such as e-commerce or e-learning. However, the creation of such plugins requires development skills and effort. We present a meta-plugin that automatically generates bespoke plugins for data management based on user-defined ER models. We illustrate the approach using an example of creating a WordPress site for managing information about courses.

Using synchronised tag clouds for browsing data collections

Tag clouds have become a popular means of visualising and browsing data, especially in Web 2.0 applications. We show how they can be used to provide flexible and intuitive interfaces to web search services over data collections by using multiple synchronised tag clouds to browse that data. A data collection can have alternative tag clouds and a tag cloud alternative visualisations, with the choice of tag cloud and visualisation at any time controlled by a combination of user selection, developer specification and default system behaviour. A search interface is defined by an augmented data model that specifies the viewer classes, their associated tag clouds and the visualisations of these tag clouds. We demonstrate the approach by describing how we implemented a web application to browse data related to researchers and their publications.

A flexible object model and algebra for uniform access to object databases

In contrast to their relational counterparts, object databases are more heterogeneous in terms of their architecture, data model and functionality. To this day, this heterogeneity poses substantial difficulties when it comes to benchmark or interoperate object databases. While standardisation proposals have been made in the past, they have had limited impact as neither industry nor research has fully adopted them. We believe that one reason for this lack of adoption is that these standards were too restrictive and thus not capable of dealing with the heterogeneity of object databases. In this paper, we propose a uniform interface for access to object databases that is based on a flexible object model and algebra.

From Static Methods to Role-Driven Service Invocation --- A Metamodel for Active Content in Object Databases

Existing object databases define the behaviour of an object in terms of methods declared by types. Usually, the type of an object is fixed and therefore changes to its behaviour involves schema evolution. Consequently, dynamic configurations of object behaviour are generally not supported. We define the notion of role-based object behaviour and show how we integrated it into an existing object database extended with a notion of collections to support object classification and role modelling. We present a metamodel that enables specific services to be associated with objects based on collection membership and show how such a model supports flexible runtime configuration of loosely coupled services.

Unified event model for object databases

Most object databases offer little or no support for eventbased programming over and above what is provided in the programming language. Consequently, functionality offered by traditional database triggers and event-condition-action (ECA) rules has to be coded in each application. We believe that a notion of triggers should be offered by object databases to facilitate application development and a clear separation of concerns. We present a general and flexible event model that unifies concepts from programming languages and database triggers. We describe an implementation of the model and how it can support the requirements of a rich variety of applications.