pentaho/pentaho-kettle · error

The function call ltrim is not valid :

Error message

The function call ltrim is not valid : 

What it means

This is ltrim's generic wrapper exception: any Exception thrown while processing a valid single-argument call (e.g. a Rhino conversion failure or regex error) is re-thrown as 'The function call ltrim is not valid : ' + e.getMessage(). The empty message here means the underlying exception's getMessage() returned null.

Solutions

1. Log/inspect the actual field value fed to ltrim; convert it explicitly with value + '' or Context-safe toString before the call
2. Guard against null: use (value == null ? '' : value) before ltrim
3. Check the step log for the preceding stack trace to identify the wrapped exception

Example fix

// before
var s = ltrim(row.rawField);
// after
var s = ltrim(row.rawField == null ? '' : String(row.rawField));

var safe = (v == null) ? '' : String(v);
var t = ltrim(safe);

function isNonNullString(v) { return typeof v === 'string' && v !== null; }

try { var t = ltrim(s); } catch (e) { // generic wrapper: message may be empty
  throw new Error('ltrim failed on value: ' + JSON.stringify(s) + ' cause: ' + e.message); }

When it happens

Trigger: Passing a non-string object whose Context.toString conversion throws, or an underlying exception with a null message (common with NullPointerExceptions) inside the try block of ltrim.

Common situations: Passing null/undefined-adjacent values from upstream fields into ltrim; passing Rhino Java objects that fail conversion; debugging confusion because the real cause is hidden by the null message.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• Please provide a valid Char to the fillString
• The function call fillString requires 2 arguments.
• The function call ltrim requires 1 argument.
• The function call rtrim requires 1 argument.
• AbsSecurityManager.ERROR_0004_UNABLE_TO_APPLY_LOGICAL_ROLES_TO_RUNTIME_ROLE

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/4ae15a4027977c90. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/steps/scriptvalues_mod/ScriptValuesAddedFunctions.java:784

    return Boolean.valueOf( bRC );
  }

  public static String ltrim( Context actualContext, Scriptable actualObject, Object[] ArgList,
    Function FunctionContext ) {
    try {
      if ( ArgList.length == 1 ) {
        if ( isNull( ArgList[0] ) ) {
          return null;
        } else if ( isUndefined( ArgList[0] ) ) {
          return (String) Context.getUndefinedValue();
        }
        String strValueToTrim = Context.toString( ArgList[0] );
        return strValueToTrim.replaceAll( "^\\s+", "" );
      } else {
        throw Context.reportRuntimeError( "The function call ltrim requires 1 argument." );
      }
    } catch ( Exception e ) {
      throw Context.reportRuntimeError( "The function call ltrim is not valid : " + e.getMessage() );
    }
  }

  public static String rtrim( Context actualContext, Scriptable actualObject, Object[] ArgList,
    Function FunctionContext ) {
    try {
      if ( ArgList.length == 1 ) {
        if ( isNull( ArgList[0] ) ) {
          return null;
        } else if ( isUndefined( ArgList[0] ) ) {
          return (String) Context.getUndefinedValue();
        }
        String strValueToTrim = Context.toString( ArgList[0] );
        return strValueToTrim.replaceAll( "\\s+$", "" );
      } else {
        throw Context.reportRuntimeError( "The function call rtrim requires 1 argument." );
      }
    } catch ( Exception e ) {

View on GitHub (pinned to f3058517a1)