Using data objects in gadgets
Data object files contain one or more data sets or data cubes. Data objects are either a design file or a store file. Data object design files contain only the information to query and add structure to external data sources. These files can cache the queried data as a data object store file.
For example, a data object design file that is only be a few kilobytes in size is saved as a data object store file. The size of the new file is a few megabytes in size because the results from data query are stored inside the data object store file. Data objects can filter data using parameters, if the BIRT developer included them. Filtered data objects limit the data that appears in all gadgets that use them.
Dashboard developers can also filter the data displayed in each gadget using the data settings of the gadget. For example, two chart gadgets using the same data object are on a dashboard. One gadget has a filter condition to display data from 2010 and the other gadget has a filter to display data from 2009. Additionally, data visualization gadgets support interactive filtering by the user.
The order of filtering is as follows:
Data object parameters
These parameters limit data displayed in all gadgets on the user’s dashboards.
Gadget data source filtering
These filters are applied to each gadget. Users can change these filters if they have permissions to edit the gadget.
Data selection gadgets
These gadgets filter any gadget that links to them.
Interactive filtering
These filters use visible data fields in a data visualization gadget. Interactive filtering are applied to data that matches all previous filtering conditions.
If data contain hyperlinks, these hyperlinks can appear in the data visualization gadgets. For example, order numbers in a data object can have hyperlinks to view the invoice for an entire order.