Report developers distribute reports to users by publishing them to BIRT iHub. Sometimes a report requires information about the iHub environment to implement application or business logic based on, for example, the security credentials of the user running the report, the browser in which the report is viewed, the server volume on which the report is run, and so on. BIRT provides an API, referred to in this chapter as the iHub API, that enables access to this type of information.

To use the iHub API in a report, you write event handler scripts in either Java or JavaScript. BIRT event handlers are associated with all the elements that make up a report, such as data sources, data sets, tables, charts, and labels. When a report is run, BIRT fires events and executes event handlers in a specific sequence to generate and render the report.

Writing event handlers in a report requires knowledge of the BIRT event model. For information about the event model and details about writing event handlers in Java and JavaScript, see Application Integrator Guide. This chapter describes the additional requirements for accessing and debugging the iHub API in an event handler.