Parameters
Parameters enable the final user to interact with the contents of the report, allowing the reports to present dynamically generated content and adapt to the needs of the user.
Pentaho Report Designer (PRD) allows the inclusion of parameters in its reports by means of a fairly nice UI. Parameters in PRD can be quite simple, such as the selection of a value from a list, or more complex, such as when nested parameters are created so that setting a value in one of them causes the modification of the values of others. This means that the data set obtained by the nested parameter depends on the values selected in another parameter. In the first case we could establish a list containing every year in which films were rented, and have the user select one of them:
In the second example, we could create two parameters so that one of them holds every country, and the other one holds every city available, and have them behave in a way such that when the user selects a country, the other parameter...