Built-in and When() functions

Four functions are part of the expression language. All other names following an at-sign are references to function rules, instances of the Rule-Utility-Function rule type. An expression can use any of these built-in functions:

Syntax	Description
These functions are part of the expression language. Their names are reserved and cannot be overridden. These functions may only be invoked using the preferred (‘@’) syntax.
`@if( boolean expression, result1, result2)`	Evaluates the condition in parameter one and then, if true, evaluates and returns parameter two, otherwise evaluates and returns parameter three. Equivalent to the Java ternary operator “?:.” Only the one appropriate result parameter is evaluated.
`@and( e1, e2, ...)`	Logical AND operation of the (arbitrary number of) parameters (Evaluated left-to-right, stopping when the result is known)
`@or( e1, e2, ...)`	Logical OR operation of the (arbitrary number of) parameters (Evaluated left-to-right, stopping when the result is known)
General purpose
`@when(name)`	Evaluates a when condition rule in the context of the primary page of the rule in which the expression appears. The parameter can be an expression that evaluates to a text value.
`@when(name, pagename)`	Evaluates the specified when condition rule using the supplied `ClipboardPage` PublicAPI object (not a page name) as the primary page for evaluation. Either parameter can be an expression that evaluates to the correct data type. Note: The primary page for evaluation is supplied as a `ClipboardPage` object, not a page name, so that embedded pages (or pages whose name is not known) can be evaluated.

You can use a Value List, Value Group, or Page Group property as an argument to the @SUM(), @MIN(), @MAX() and @AVERAGE().