About linking gadgets together
Gadgets link to each other so that information from one gadget can change the information displayed in another gadget. One gadget publishes information, and one or more other gadgets subscribe to the publishing gadget, linking the two gadgets together. Gadgets, like data selection gadgets, publish their data when a user changes a value, such as selecting an item from a list.
This process supports the following data scenarios:
Filtering visual displays based on parameter selection by a user
Cascading choices, where selections in one data selection gadget populates choices displayed in another data selection gadget
Interlinking data sources, where changes in a data selection gadget can affect gadgets using data from different data objects
User selection‑triggered scripts that execute global JavaScript code
For example, a chart gadget and a report gadget link to a list gadget that contains the names of countries. When a user selects a country in the list gadget, the chart and the report gadget update with data related to the selected country.
Figure 6‑1 shows linking gadgets receiving filtered data based on user selection. The filtered data is then displayed to the user.
Figure 6‑1 Gadgets linking to list gadget
Each linked gadget can use different BIRT data objects as data sources. Using different data objects requires that the value published by the data selection gadget matches a data field in the linked gadgets.
Data selection and other gadgets that use the same data objects automatically link together, when added to the same dashboard. Automatic linking requires that gadgets use the same data object. Developers can manually add or change links in the gadget menu, configure filters on specific fields, or configure gadget events to monitor.
