General Specifics

The following general specifics apply to JavaScript for the Designer:

• In the script, input and output parameters are known by their name.

• If you want your function to return a value

  • add the return parameter to the operation signature

  • use a return statement for the value you want to return

  Please note that nothing will prevent you from returning values without having the return parameter defined on the operation.
  

  • If you defined a return parameter but didn't use a return statement in your script, the return value is NULL.
  • If you did not define a return parameter but exited the JavaScript with return <something>, the value of the return parameter can not be accessed by the operation caller.
• Every unassigned xUML object property is set to NULL.
• The xUML object properties defined in the model cannot be deleted.
• The JavaScript code will be executed in strict mode ("use strict"), using the V8 engine.

Limitations

• There are some limitations to array handling due to the ECMA standard. This is discussed on JavaScript Type Mapping > Arrays.
• You cannot call operations that are defined on Designer classes from a JavaScript. This applies to both static and non-static operations.

Exception Handling

Thrown exceptions will be propagated outside the operation as standard Runtime exceptions. All JavaScript exceptions will be reported to the Designer as SCRIPTSM/1. They can be caught using the JavaScript statement try{} catch(){}. You can throw a user-defined exception using the  throw statement.