## Chapter 25 Scripting reference

BIRT provides several JavaScript classes in addition to the native JavaScript classes that are a part of Rhino JavaScript. A report developer can access any of the BIRT classes and their properties and functions when writing an expression. The BIRT classes appear in the Expression Builder's Category list as BIRT JavaScript objects.

BIRT event handlers written in Java code cannot directly access the BIRT JavaScript classes. It is possible to partially circumvent this restriction, however, by defining a new user property on an element and assigning the value of that property using a JavaScript expression. The JavaScript expression can use any of the BIRT JavaScript objects. Since Java code has access to the value of a user property, Java code can, in this way, access the result of evaluating a JavaScript expression. The primary restriction of this technique is that the expression is evaluated at the time the element is created and is therefore static.

For more information on writing Java scripts, see Using Scripting in a Report Design.

The following sections provide reference information for the BIRT JavaScript classes.