· Visualization

The Polychaeta architecture is illustrated in :: FIGURE 7 :: .

· Polychaeta server

The Polychaeta server is responsible for the Content Management System (CMS) and the layout layer. The CMS layer holds core data elements such as websites,webpages, images, and text elements. The layout layer is based on the CMS layer and provides layout specific data for the core objects.

The Polychaeta server provides services to manage both the CMS and the layout layer, and a service to handle incoming HTTP requests sent by web browsers. The latter is also in charge of collecting log data. :: TOP ::

· Polychaeta adaptation

Polychaeta adaptation holds the sugar scape layer which adapts a complete website by means of the IBux framework and a layout strategy. The IBux framework is responsible for moving webpage elements according to the sugar scape model rules; the layout strategy transforms that model into a "real" web layout.

The adapted layout data is written back to the server using the Layout- Facade.  :: TOP ::

· Polychaeta client

The Polychaeta client modifies the CMS data. The client uses the CMSFacade to connect to the server and to create, retrieve, and update data.  :: TOP ::

· Browser

A web browser visualizes the generated webpages. The browser requests webpages from the WebFacade and sends log data back to the server.  :: TOP ::

· Communication

Compared to the first version of Polychaeta, we have completely revised the communication between the different parts:

· We use asynchronous messaging provided by Java Messaging Service (JMS) to implement observer/event handling. The observable object (notifier) publishes messages to a topic which is subscribed by the observer (listener).

· Data Transfer Objects (DTOs) are used to exchange data between polychaeta parts. Compared to the object-oriented (OO) paradigm, which typically uses remote method invocation, the DTO approach implements a more serviceoriented mechanism. A facade provides (service) methods that meet the caller's requirements and deliver well-grained data objects. This helps reducing network traffic, leading to more scalable applications and higher performance.   :: TOP ::

  :: CONTACT ::