JasperGrails Tutorial
Author : Marcos Fábio Pereira (marcos [dot] at [dot] embedded.ufcg.edu.br)
Contributers : Egon Jensen, João Paulo
Index
- Releases
- Step-by-step guide
- FAQ
Releases
Version 0.7.6
New features:
The user can to retrieve data report from domain classes:
Attribute 'from' was included in jasperReport tag.
XLS parameters were improved: (Thanks to Sebastian Esch)
One page per sheet;
Auto detect cell type;
Remove empty space between rows;
White page background is disabled.
Bug fixed:
Plugin didn't work on Linux (File separator was wrong). (Thanks to Sebastian Esch)
Version 0.7.5
Bug fixed:
bug in JasperService.groovy that can cause connection leaks, connection is never closed. (Thanks to Pass F. B. Travis)
----
Step-by-step guide
This guide shows how to call JasperReports from within Grails.
Written by Egon Jensen and Marcos Fábio Pereira.
I liked the Racetrack application in Getting Started with Grails, but I'm missing something. Wouldn't it be nice if you were able to create a report with all the races in, say, PDF format?
Don't worry; JasperReports can do that, and it is easy to use in Grails.
To follow this tutorial, you first have to create the Racetrack application from Getting Started with Grails. But of course you can use your own application, just remember to do the necessary changes as you follow along.
First you have to install JasperGrails
grails install-plugin jasper
Now modify "Racetrack/grails-app/views/race/list.gsp"
[...]
<div class="paginateButtons">
<g:paginate total="${Race.count()}" />
</div>
<g:jasperReport jasper="all-races" format="PDF" name="All Races" />
</div>
</body>
</html>
That's right; all we need is one line 
Now start the application
Open a browser, and go to http://localhost:8080/racetrack
Logon and below the Race List, you'll now find a PDF icon.
Press the icon, and ...
Ups!
We forgot the JasperReports file 
As you can see in the error message, we are supposed to create and save "all-races.jasper" in "racetrack/web-app/plugins/jasper-0.6/reports/". After doing that, use the browsers back button and try the PDF icon again. This time it works better.
Open the file and you get a beautiful report with all the races.
OK, I admit it, JasperReports (and iReports) is not my strong side.
Besides, this is a tutorial for JasperGrails, not for JasperReports
Let's try another example.
This time we will export all the registrations for a given race to Excel. Again we start with modifying the view: "racetrack/grails-app/views/race/show.gsp"
[...]
<div class="buttons">
<g:form>
<input type="hidden" name="id" value="${race?.id}" />
<span class="button"><g:actionSubmit class="edit" value="Edit" /></span>
<span class="button"><g:actionSubmit class="delete" onclick="return warnBeforeRaceDelete();" value="Delete" /></span>
</g:form>
</div>
<g:jasperReport jasper="registrations" format="XLS" name="Registrations">
<input type="hidden" name="race_id" value="${race.id}" />
</g:jasperReport>
</div>
</body>
</html>
We want to pass an argument to JasperReport, and we can do just that with a hidden field. Remember to include the JasperReports file.
This time we will try with the jrxml format. Thus we save "registrations.jrxml" in "racetrack/web-app/plugins/jasper-0.6/reports/".
Remember to include the following in "registrations.jrxml", to accept the argument we send from "show.gsp":
<parameter name="race_id" isForPrompting="false" class="java.lang.String">
<defaultValueExpression><\!\[CDATA\["<parameter error>"\]\]></defaultValueExpression>
</parameter>
<queryString><\!\[CDATA\[select * from registration where race_id = $P{race_id}\]\]></queryString>
Click on "Turkey Trot", and below Show Race, we now have an Excel icon.
Press the icon and open the resulting file.
But, if we don't want to use a SQL query to generate the report? If we want to use domain classes?
The user can also to retrieve data to the report directly from domain classes, without use SQL queries in .jrxml file. It's need only to set the 'from' attribute in jasperReport tag, like showed bellow:
<g:jasperReport from="Race.list()" jasper="all-races" format="PDF" name="All Races" />
It's correct! The 'from' attribute must be without '${}'. The code inside it will be evaluate by the plugin, when the user click in the icon.
Now, the .jrxml file can be defined without a datasource. The only thing you have to remember is to set the name of all fields in the report with the same name of the attributes in the domain class.
FAQ
Nice job!