12.1 Introduction

Although TXT2XML and XML2COB are not GUI tools (see chapter ), it's perfectly understandable that some people don't like the command line. That's why a GUI front-end was written for non-mainframe platforms. There is a lot of programming techniques for GUI applications available on the Internet and choosing one of them was not simple. Some requirements were established : the GUI front-end had to :

• be portable,
• be easy to write,
• use known standards and software.

Thinlet http://thinlet.sourceforge.net/ was chosen. It's a GUI toolkit, a single Java class that parses the hierarchy and properties of the GUI, handles user interaction, and calls business logic. It separates the graphic presentation (described in an XML file) and the application methods (written as Java code). Thinlet usesXUL (XML User Interface Language) which is a markup language for describing user interfaces. With XUL you can create rich, sophisticated cross-platform applications easily. Here is an example of an XUL file :

Figure: XUL sample file.

Of course, if you are a shell or a 'DOS command prompt' fanatic, you can still continue to use TXT2XML and XML2COB Rexx scripts on a command line.