Developer's news
 

How Appliweb is working ?

 

et's compare actual web technology with AppliWeb.
The following drawing will show you how you read html pages from a webserver :



Now substitute "Web Browser" with "AppliWeb", and "HTML" with "Java screen", et voilà ! Easy now ?

The HTML pages

HTML pages possess undeniable qualities. Nevertheless they don't offer sufficient possibilities for a satisfactory business use : page navigation is uneasy, the user interface is poor (only 6 controls !), the programming language is far from being a standard,...

Just try to use an HTML-based messaging service (like netscape webmail or hotmail), and check the time needed to send a single message !
Of course, you don't have to wait really long between each action (click on a link), because each time it only downloads a single page.

Appliweb permet de cumuler les avantages de ces 2 mondes, tout en éliminant leurs inconvénients.

- Il charge chaque page une par une, d'où un temps d'attente très court.
- L'application est entièrement sur le serveur, le client n'étant qu'une "coquille vide", un navigateur.
- On peut faire très facilement des applications inter-serveurs. Par exemple, un logiciel de gestion de compte qui affiche des cotations venant d'un autre site.
- On dispose enfin d'une véritable interface utilisateur conviviale !
- N'utilisant que le protocole HTTP, il est compatible avec tous les serveurs et firewall !

The applications

Appliweb

s it difficult to see real applications (or Java applets) over the internet ? yes ! Because of the lengthy loading process, no user can wait 10mn for the app to download before using it.
On the other side, once loaded, the patient user can appreciate the better productivity of the greatly improved applet user interface.
ppliWeb allows you to get the best of both world.

- It downloads pages one at a time, delivering fast access to functionality.
- The application resides entirely on the server, the client needs only a special browser.
- You can easily make inter-server applications (for example, an account management app that shows realtime quotations from another site)
- Finally you have a friendly user interface for the web!
- It only uses HTTP protocol, so it works with all the webservers and firewalls !

The table below illustrate the possible ways to create a web application

Features HTML Application Applet AppliWeb
Browsing        
Downloading time None Very long Very long None
Time for each action One page download Short Short One page
From one server to another Yes No No1 Yes
User Interface        
Modal dialog boxe No Yes Yes Yes
Dynamic tables No Yes Yes Yes
Menus No Yes Yes Yes
Multi-Windows No Yes Yes Yes
Tabbed panels No Yes Yes Yes
Toolbars No Yes Yes Yes
Tree controls No Yes Yes Yes
Other        
Program update File copy on server Install on all clients File copy on server File copy on server
Compatibility Full, except for Javascript OS specific Not full between browsers Full because Java

1You can call a page on a different server with an applet, but cannot make the applet communicates with a different server.

 

How to use it ?

Either you design your user interface like for a standard Java application. You simply add hyperlink components.
AppliWeb delivers a tool, called the Serializer, that will save your interface to your disk.

 

Or you write XML files describing your user interface, with the hyperlink components. For now, AppliWeb use the BML (Bean Markup Language) standard from IBM which seems to be the most powerful, but other exists (XWingML, Prototype, ...) and may be supported in the future. Informations on XML and tools can be found at http://www.exoffice.com/exolab.html, www.ibm.com/developer/xml, www.xml.org.

As soon as you copy them in your webserver, you can start browsing your application !
If you need some dynamic pages, you can write servlets that will put the datas into the screen before sending it to the client.

 

 

 

Vous placez tous ces fichiers sur vôtre serveur web, et vous pouvez déjà naviguer dans votre application !
Si vous voulez faire des pages dynamiques, vous écrivez des servlets qui vont placer les informations dans ces écrans avant de les envoyer sur le client.


(c) 1999-2000 COLLIN Gérard