I wrote some actions which generates dynamically PDF files. something like: reports/reportGenerator.action
when I call reports/reportGenerator?param=dialy
The solution is simple, add property to your jrxml file by clicking right on your jrxml in the iReport designer and press properties then press add :
Property name
net.sf.jasperreports.export.pdf.javascript
Property value
this.print({bUI: true,bSilent: true,bShrinkToFit: false});
This property will print automatically in the client side, I'd add it and it work perfectly.