A Lightweight Presentation Model for Database User Interfaces

The Teallach project is building a system which eases the design and implementation of user interfaces (web-based or otherwise) to object-oriented database applications. Teallach takes a model based approach and is constructing its system around three main models - a domain model which describes the database structures with which Teallach can cope; a task model, in which the user-involved aspects of the application can be described; and a presentation model. The presentation model is intended to support the storage of user interaction objects, so that these objects can be found, customised and composed into user interfaces suitable for the tasks. In seeking an appropriate presentation model, we have found that previous models are either those underlying toolkits, which are overly concrete and detailed, or are abstract models based entirely around the look of the interaction objects, but not their intended role. We are implementing a model which describes each interaction object in terms of its purpose, the kinds of data with which the user is allowed to interact, constraints on its use, and a description of configurable aspects of the interface in terms of the ways in which they support interaction. This paper describes this model and gives examples of its use.