subject: Debugging BIRT Javascript [print this page] I was creating a report in order to answer a query that had been raised by a reader of BIRT for Beginners where they needed to use the List Box parameter within a report. In order to do this with BIRT I needed to use some Javascript in the beforeOpen event of my data set and I had a problem with the creation of this script. So I needed to find a way to examine the values of variables while the script was running to see what I was dealing with and where my error was coming from.
There are ways to switch on logging from BIRT and dropping values out to a log file, which you can examine after an execution, but this is a little long winded for quickly creating and debugging snippets of Java code, so I wanted to find a faster, more immediate way to interrogate my script variables.
Looking around on the web I came across a method that involves running BIRT in the console mode, which means that you get all output from your script generated immediately to a console window.
This is great because it means that you can tweak your script and learn the results immediately, making debugging a quick and efficient process.
CONSOLE MODE
First we need to launch BIRT in Console mode, so we get to see our console window alongside the main BIRT IDE.
Do this by running eclipsec.exe, using a command line like this:
"C:BIRT 251eclipsec.exe"
Notice that this is different to the usual eclipse.exe with the addition of the letter "c", you will notice that BIRT runs in the normal way, but with a console available too.
THE BASIC REPORT
To demonstrate the use of the console window for output, create a simple listing report based on any data set that you choose. For my example I used the ClassicModels customer table and just listed out all customers.
ACCESSING THE SCRIPT AREA
Next I created a small piece of script in my report, which simply setup a for loop, to display a counter. There are various areas within a BIRT report where you can access the scripting area so for our example I am going to use the data set.
Select your data set and then click on the script tab at the bottom of the main layout window, ensure that beforeOpen is the selected script event.
