Cascading groups can be used:
- through the native parameters dialog of Visioneo UI (see image below)
- through native external parameter portlets, perfect for mobile devices
A cascading group is especially useful when we have to deal with very large combobox parameters. Typically we choose a category in a first combobox, and then select an item within this category. BIRT allows to design as many levels as we like in a cascading group.
This feature is available in the professional edition only. Two demo reports dedicated to cascading parameters are now bundled in Visioneo packages of the professional edition.
Each time an item is selected, a BIRT task is dynamically triggered to get possible values of the next level. Eclipse designer allows to apply any kind of query & filter across levels. In this case, we run a query on a database table to extract existing order dates. BIRT is so flexible that we can even make use of multiple datasources within a cascading group! See release notes of version 1.3 for more informations.