I want to create the reports for In-workflow,completed,pending workflow documents reports in dashlets with pdf format.
How we will do this??
First things you can not create pdf report in dashlet.
What you can do is , You can create custom dashlet which can display the data which you required. and finally you can export the data in pdf format.
Below link will help you in creating the custom dashlet.You can use aikau or yui any of it.
Share Dashlet Using YUI | Krutik Jayswal
Aikau Dashlets | Alfresco Documentation
For exporting data in PDF, you can refer below library.There may be other library also which you can use.
Creating PDF with Java and iText - Tutorial
Retrieving data ...