Webstructor Applet


What you can do with Applet

First, in order to run Webstructor Applet under the web browser, you need to have browser with Java Development Kit version 1.17 support.

When running Applet, you can do almost everything you can do while running Webstructor as Application. From some perspective, it is more convenient as long as you don't need to take care about version upgrades - you always run the most recent version.

The most important benefit of running Webstructor is Applet is that it works in sync with your web browser. That means, you can follow hyperlinks in Webstructor the same way you follow these hyperlinks in the web browser.

At the same time, several restrictions do apply. For example, if you don't want just browse data and make some temporary changes but you want your changes to be saved somewhere, you need to make sure that your Applet loads data not from plain text file, but from active server-side servlet.

For example, if you look at the World choice (GUI control) of Visual Mind Applet loaded from http://www.webstructor.net/worlds/index.html and see something like "index.txt" or "http://www.webstructor.net/worlds/index.txt", than data are loaded from the file "index.txt" via standard web server GET HTTP command and you have no way to change it. In this case, Post button is disabled.

For another example, if you look at the World string of Applet loaded from http://www.webstructor.net/worlds/animals.html, you will see something like "http://www.webstructor.net/servlets/w?animals". That means, data are loaded via Servlet and you can click Post button to save your work.

Another issue with Applet is that you don't have access to Java standard output as you do when running Java Application. You don't need this because most of system output is directed to Visual Mind Console. Still, if something goes wrong, it is useful to see Java output - at least - to file a bug report. To see Java output, you should enable Java Console in your browser. How to do that, depends on browser you use.

What Applet can't do for you

First, it can't run under browser with Java Development Kit version below 1.17. You can detect it as follows. If you have visited any page listed here and you didn't see anything, enable Java console in your browser and start your attempt again. If you fail again, look into Java console output. Likely, you will see some exceptions indicating that Java Virtual Machine failed to find some methods in the classes. If so, you need to upgrade your browser.

Second, it can't save your work for you if it have data loaded from plain text file on the web. In this case, you can browse the world, make any changes in it but all your changes will be lost as soon as you close Applet. You will not be able to click on Post button to save your changes unless Applet data are loaded from Servlet. You can read more about this on another page.

Third, because of JDK version restrictions, you can't deal with transparent objects in 3D Views (with Camera Projector). You still can assign transparent colors to objects, but they will not be transparent in the View - you will not notice any transparency.

Fourth, Applet can not directly communicate with more than one other application (the web server it is loaded from or Servlet on the same server). That is, you can not do anything with peer-to-peer data distribution while running Applet.


(C) Copyright 1988-1998,2001 Anton Kolonin

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