Here is the native listbox widget used to enter multiple values in a birt parameter, in this example it is the "Product(s)" parameter. This component has been embedded in visioneo reportlet a long time ago, but now we can display it through the external parameter portlet (Professional Edition). It makes use of a powerful open source widget (MIT), therefore we can easily upgrade or customize it if necessary.
The report is automatically refreshed when this listbox is closed, if the selection has changed.
Everything is native, we don't have anything else to develop but a BIRT report :
- Selection choices extracted from the birt engine,
- Ajax communication between the report and the parameter,
- Default values taken from the reportlet application,
- Synchronization with the existing dialog parameters and "back to previous"
Notice this demo report returns values for all products when the selection is empty, but this is obviously an arbitrary choice we can control this behavior from the report design.