Introducing Custom Report Items
Microsoft SQL Server 2005 Reporting Services provides a rich set of tools for building and publishing enterprise reports, managing security and subscriptions, and extending the reporting functionality through a comprehensive API. Reports are defined using an XML-based language called Report Definition Language (RDL). RDL provides a set of instructions that describe layout, query information, and item types for a report. It is possible to extend RDL by writing a custom report item.
A custom report item is an extension to the RDL that allows developers to add functionality that is not natively supported in RDL, or to extend the functionality of existing controls. The custom report item is comprised of a run-time component, which is called by the report processor at run time, and a design-time component, which allows the custom report item to be available in Report Designer.
Developers who need to integrate Reporting Services into their applications may require functionality that is not natively supported in RDL. This may include items such as: map controls, horizontal lists, columnar lists, and repivotable matrixes. A run-time custom report item component can be developed and distributed with an application to fill this need.
In addition to providing functionality that isn’t natively supported, some developers may want to extend existing functionality with alternative versions of controls that are already included with Reporting Services. In this scenario, a developer could provide three components: a run-time component, a design-time component, and a design-time report item conversion component that converts an existing report item into a custom report item on demand.