Execute JavaScript expressions and return the result.

Summary

Deprecated: Javascript script engine removed in Java 15. This macro might not work anymore and might be removed in future versions.

The js macro executes one or more JavaScript expressions using the Java ScriptEngine and returns the value of the last expression or any output produced.

Syntax 

${js;<expression>[;<expression>...]}

Parameters

  • expression - One or more JavaScript expressions to execute

Behavior

  • Executes all expressions in sequence
  • Returns the value of the last expression
  • If no return value, returns stdout output
  • Has access to domain object (Processor instance)
  • Persistent context across macro invocations
  • Can load JavaScript from javascript property

Examples

Simple calculation:

${js;2 + 2}
# Returns: "4"

String manipulation:

${js;"hello".toUpperCase()}
# Returns: "HELLO"

Multiple expressions:

${js;var x = 10;x * 2}
# Returns: "20"

Access properties:

${js;domain.getProperty("version")}

Use Cases

  • Complex calculations
  • String transformations
  • Conditional logic too complex for macros
  • Property manipulation
  • Dynamic value generation

Notes

  • Uses Java’s ScriptEngine (Nashorn/GraalVM)
  • Context persists between calls
  • domain object provides access to bnd
  • JavaScript property can define initialization code
  • Errors reported to build
  • Warning: Adds JavaScript engine dependency

See test cases in MacroTestsForDocsExamples.java