Using data objects in gadgets

Data object files contain one or more data sets or data cubes. Data object design files use the file-name extension .datadesign. Each time they are queried for data, they make a new query to their original data sources. The BIRT iServer can cache this data as data object store files to avoid on-demand queries of external databases and to ensure that multiple dashboards use the same data. Data object store files have the file-name extension .data.

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 designers 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:

1	Data object parameters

These parameters limit data displayed in all gadgets on the user’s dashboards.

2	Gadget data-source filtering

These filters are applied to each gadget. Users can change these filters if they have permissions to edit the gadget.

3	Data selection gadgets

These gadgets filter any gadget that links to them.

4	Interactive filtering

These filters use visible data fields in a data visualization gadget. Interactive filtering are applied to data that matches all of the previous filtering conditions.

(c) Copyright Actuate Corporation 2011