Friday, March 09, 2007

I still don't know enough, but I know something

For quite a while I've wanted an easier way of using Jasper Reports in my web applications. My first go around with Jasper Reports involved implementing custom servlets for Jasper reports and using (what I now realize is) a giant kludge to add to and maintain those reports and compile and run them on the fly. I've clearly learned a lot since that first try. My second go around with Jasper Reports involved precompiling them with an Ant task and using report views in Spring after I moved to the Spring framework. This was a lot better than what I had been doing, but I still made mistakes when I didn't quite know the best way to get parameters into my report.

Now I'm about to start with round three. This round started with an epiphane the other day: why not use a tag library to insert a Jasper Report into a page rather than dealing with entire views ? This would surely be far more compact and would even look far better. After googling for several hours and finding nothing even close to satisfactory in this regard, I decided to make my own tag library. I whipped up the tag library tutorial on Sun's website, and within a couple of hours, I had the very beginnings of a rudimentary tag library going, and I had successfully embedded a Jasper report within a page of one of my web apps. (It was a piece of shit test report embedded within a div, but it was more than enough for proof-of-concept).

This short snippet:
<div style="overflow: auto;">
<jr:report printerName="${printerName}" reportName="test" reportParameters="${sessionScope.mymap}"/>

Showed just how powerful and useful tag libraries can be. Combining this with Spring's dependency injection made things a lot easier too. I thought to myself: this could be really useful. And I was really surprised that nobody else had done this already. In light of my epiphane, I think I'm going to start up a source forge project for this, probably call it JasperTags. Who knows, it might even be useful. But there's a bunch of other stuff I need to learn first, like Maven 2, JIRA, and numerous other little useful developer tools so I can at least put on the facade of being a competent open source developer.

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