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Yoix / YWAIT, the Yoix Web Application Instant Template

YWAIT provides a substantial and expandable framework for the server side of a Web based application that uses Perl for cgi scripts and relies on Java and the Yoix interpreter to provide the client side GUI. We've used variations of this architecture, which we described in a 2002 paper, to build large web based production systems and we've done it for many years now. Even though we've made many changes in this version you can still expect reliable, flexible, production quality behavior from the YWAIT client and server software.

What it is

The source package includes everything you need to build and install the server software on systems that are equipped with standard Unix and Java development tools and run a web server, like Apache. YWAIT also builds an installer for the client-side software as well as the HTML document that is displayed when you point a browser at the application web site to provide a link to that installer. The client software is the Yoix interpreter, possibly augmented by custom modules, in an executable jar file that starts the interpreter using a very small application specific class that knows how to get to your web site. Clients run the installer once and then rely on the server to keep everything, including the jar file installed on their system, up to date.

We've used variations of this architecture since 1998 and we think of it as a Web Application, but you may prefer to call it a Java Application, a Rich Internet Application or something else altogether. There's no browser or JavaScript involved in our architecture and we don't rely on HTML or XML. Instead, Java takes the place of the browser and we use the Yoix interpreter, which is written in Java, for scripting and providing a platform independent interface to Java. The format of the data exchanged between a client and the server is not specified. Instead, the Yoix script that builds the screen used to present the data and the cgi script that delivers data to that screen make the decision, and they can pick any format they want, including HTML or XML.

This architecture and our desire to use it and Java to deliver real production applications inside AT&T is why Yoix was written and why platform independence was and still is a primary focus of the Yoix interpreter. A single (rather large) Java application, namely the Yoix interpreter, concentrates really hard on tricky Java issues and also happens to accept a reasonably simple scripting language. By placing the Yoix interpreter between the Java Virtual Machine running on a client and Yoix scripts sitting on a server, you'll most likely end up with a portable application. But there's an advantage even when you don't - one Java program means one place to address portability issues, and when it's done right Yoix scripts everywhere benefit.

So it's the Yoix scripts sitting on the server that are endowed with the coveted Write Once, Run Anywhere property and it's the Yoix interpreter that we change when portability issues arise. The interpreter lets us reuse our Java code while the language, which intentionally omits a way to access arbitrary Java features, limits Yoix scripts to the features that are exposed by the Yoix interpreter. An obvious downside is that the Yoix interpreter always lags Java, but the same thing undoubtedly can be said about any substantial Java application. Java's latest and greatest features usually take time to appear in production programs, and that's really the way it should be.

With the Yoix scripts residing on the server, application maintenance and updating are easy. Just change or add new script files on the server and they are automatically distributed to the clients as with any web documents. Also, since the server-side is just the familiar web server model, setting up the application's back-end requires no new skill sets. For example, databases can be accessed using typical perl/odbc methods and the data can be transferred to the client GUI using any number of suitable approaches as mentioned above.

What you get

YWAIT is the complete source - from makefiles to application installer - for a fully functional Yoix web application framework. With YWAIT, you can focus your resources on writing your application specific code and not worry about all the tedious boilerplate required for a complete, production-quality application since YWAIT gives you that part. The YWAIT framework delivers a functioning generic stub application out-of-the-box that includes:
  • source code;
  • make files (a standard make program such as the freely available GNU make is required to process the make files);
  • instructions and usage examples;
  • administrative features, such as:
    • activity logs;
    • broadcast messaging;
    • adjustable shut-out settings (block all users, block non-administrative users, etc.);
    • automatic update of the Yoix interpreter and extension modules based on release number;
    • password access control;
    • inactivity detection / log-off;
  • multiple system instantiation capability (prototype, development, demonstration and production);
  • a client application installer (installs the Yoix interpreter on the client machine);
  • and much more.

Getting started

After downloading the YWAIT package from our download page, look at the top-level README file to see how to configure the application for your environemnt. Configuration is pretty easy and involves supplying basic information like the name of your application, where it is to be installed, the URL to reference it, and so on. You will, of course, also need to configure your web server appropriately in the same way you would for any web site consisting of document files and CGI scripts.

As always, contact us if you have questions.

 

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