ActiveViews Screenshot Presentation

INRIA-Rocquencourt, France

University of Tel Aviv, Israel

Ardent Software, USA

This document contains screenshots of the demonstration of the ActiveViews System  as it has been presented at the 25th International Conference on Very Large Data Bases, September 7-10, 1999, Edinburgh, Scotland, UK.  A complete presentation of the ActiveViews System can be found in the conference proceedings of the same conference.

(Best quality of the presented screenshots can be obtained by increasing the size of the browser window)

Active Views: Short Overview

Electronic commerce is emerging as a major Web supported application. This demonstration shows that database technology can, and should, provide the backbone for a wide range of such applications. More precisely, we demonstrate the ActiveViews system, which, relying on an extensive use of database features including views, active rules (triggers), and enhanced mechanisms for notification, access control and logging/tracing of users activities, provides the needed basis for electronic commerce.

Based on the emerging XML standards (DOM, XML query languages, stylesheet labguages, etc.), the system offers a novel declarative view specification language, describing the relevant data and activities of all actors (e.g. vendors and clients) participating in electronic commerce activities. Then, acting as an application generator, the system generates an actual, possibly customized, Web application that allows users to perform the given set of controlled activities and to work interactively on the specified data in a standard distributed environment.
 

The ActiveViews is based on the following technical platform :

Example: Electronic Store for Musical Equipment

The example presented during this demonstration is an electronic commerce application for musical equipment. XML data has been provided a French online department store and represents a catalogue for musical equipment. The application defines two views for customers and vendors. The following screen shots illustrate a session of some customer browsing the catalogue and communicating with some vendor.  More precisely, customers can : On the other hand, vendors can: The complete application is described in a declarative AVL specification file.

Demonstration

Screenshot 1
The first screenshot shows the screen of a customer who has entered the electronic store and started activity shopping.  The displayed HTML page contains all variables and methods defined in activity shopping. The frame with title catalog corresponds to a variable catalog which has been declared in the ActiveViews declaration file. The value of this variable is an XML document obtained by the XOQL query also specified in the same declaration. Observe the definition of the different modes for the elements in the query result  : the catalogue is read in deferred mode, i.e. document nodes are loaded into the view at demand during the browsing activity of the customer.  The only exceptions are nodes corresponding to elements of element type ARTICLE and NAME that are loaded immediately with their parent nodes. Displayed buttons correspond to view methods also declared in the view specification. For example, button Add Article to Caddy corresponds to method  add_to_caddy.   Before clicking on this button, the customer must browse the catalog and select an article, which becomes the argument of the corresponding method call.

Initial customer screen

Screenshot 2
The second screenshot shows the customer's screen  after having defined an initial budget, browsed the catalogue, and added some articles to his shopping cart (caddy).  Observe that the remaining budget is calculated automatically as the difference between the initial budget and the sum of the price of the articles in the shopping cart.
 
 

Customer browses catalog

Screenshot 3
Suppose the customer has clicked on button contact_vendor. This action has created a notification which fires a rule defined in the vendor's view specification.  Before executing the rule body, the rule manager verifies if the vendor is responsible for the corresponding category of musical equipment (category=c) and is not already in contact with some other customer (customer=null). The rule body will initialize the customer variable in the vendor view and execute a method accept_contact for informing the customer view that the contact request has been accepted. We will not go into detail about the complete protocol for establishing a contact between the vendor and the client. The following screenshoot shows the screen of a customer who has contacted a vendor and asked to lower the price of the displayed article.

Customer contacts vendor

Screenshot 4
The following screenshot shows the vendor's screen  after  having received the question of the customer (Discussion: "Could you lower the price").  Observe that the vendor is automatically informed about all browsing activities of the customer (frame customer_view). The information in this frame is refreshed by an active rule which is fired by the customer's browsing steps and creates notifications for the vendor's view.   Since the vendor is allowed to change the price of an article (mode write), he will update the price.

Vendor lowers price

Screenshot 5
The final screenshot shows the customer's screen after the modification of the price by the vendor. Observe the warning besides the PRICE attribute . In fact, the price has not been changed yet and the customer simply clicks on the corresponding field in order to obtain the new price.

Price has been changed