This condition is a Tcl script that is substituted and then evaluated by Tcl's expression parser.  This is not a condition that is used for full scripts.  It is used for a combination of expressions that are combined together.  To use an actual Tcl script as a condition, use the Execute Script Condition.

Standard Properties 

See Standard Condition Properties.

Advanced Properties

Script

A Tcl expression to evaluate.  The entire expression is substituted for virtual text before being evaluated.

Example

The following example is a valid Tcl expression:

[string is true <%RunningInstaller%>] && [string is true <%UpgradeInstall%>]

Note that this an expression, not a full Tcl script.  An expression is multiple commands that are strung together using expression operators like && and ||.  The following is not a valid expression:

set test1 [string is true <%RunningInstaller%>]

set test2 [string is true <%UpgradeInstall%>]

return [expr {$test1 && $test2}]

This is a full Tcl script to be evaluated, not an expression.  This type of script can be used in the Execute Script Condition, but not in a Script Condition.