title: JasperServer using REST to run a report with data source specified at run time
body: <p>I have no problem executing a report on JasperServer using the RESTful api when the report unit has data source predefined.</p>
  
  <p>What need to do though is allow my customers to select what database they want to run the report against when they are getting ready to execute a report. I assumed that when I make the PUT request to run the report I could simply throw  the data  source resource descriptor in the ReportUnit resource descriptor passed in the PUT but it doesn't seem to work.</p>
  
  <p>I even went as far as to pull the resource descritor for the ReportUnit when it had the data  source predfined. Tested that passing that resource descritor in the PUT worked. Then removed the predifiend data  source  and tried executing the report again using the exact resource descriptor I pulled previously and it would not work.</p>
  
  <p>Is this possible? </p>