Creating custom report functions

Report authors create report expressions using the expression editor. The expression editor provides a list of functions that can be used in expressions. In addition to the functions that are available by default, such as Today(), ReportDate() or ReportName(), you can create custom functions and make them available to report authors by defining report function libraries.

All functions available through the expression editor must be identified in the function definition service, a series of files that tells the expression editor what functions are defined. Report function collections are provided to report authors through dynamic load libraries on Windows operating systems, in shareable libraries on UNIX operating system, or in shared object files on the Linux® operating system.

Many types of function metadata definitions are shared among IBM® Cognos® applications and their components. Only the requirements for defining custom report functions are outlined in this chapter.

To make custom report functions available to report authors, you:

For an example, see Example of a custom report functions implementation.