pentaho/pentaho-kettle · error · RuntimeException

The function call ltrim requires 1 argument.

Error message

The function call ltrim requires 1 argument.

What it means

ltrim strips leading whitespace from a string and requires exactly one argument. When ArgList.length != 1 it throws this RuntimeException. The check sits inside an outer try, but this specific throw happens before the per-argument processing.

Solutions

1. Call with exactly one argument: ltrim(str).
2. Remove any second character-set argument; if you need custom trimming, use str.replace(/^\s+/, '') or a char-class regex in JavaScript.
3. Ensure the field value is passed explicitly, not assumed from context.

Example fix

// before
var trimmed = ltrim(name, ' ');
// after
var trimmed = ltrim(name);

if (arguments.length !== 1 || typeof str !== 'string') {
  throw new Error('ltrim requires exactly one string argument');
}
var trimmed = ltrim(str);

function isStringArg(v) { return typeof v === 'string' || v instanceof String; }

try {
  var trimmed = ltrim(str);
} catch (e) {
  if (String(e.message).indexOf('requires 1 argument') !== -1) {
    throw new Error('Call ltrim with exactly one argument');
  } else { throw e; }
}

When it happens

Trigger: Calling ltrim() with no arguments, or ltrim(str, chars) with a second character-set argument (not supported by this API).

Common situations: Porting from ltrim implementations (e.g. Oracle/PHP) that accept a character list as the second argument; calling without arguments expecting it to operate on a bound field.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• The function call initCap requires 1 argument.
• The function call removeDigits requires 1 argument.
• The function call rtrim requires 1 argument.
• Please provide a valid Char to the fillString
• The function call date2str requires 1, 2, 3, or 4 arguments.

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/8ecc4abcd3c7821c. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/steps/script/ScriptAddedFunctions.java:751

    } else {
      throw new RuntimeException( "The function call isCodepage requires 2 arguments." );
    }
    return Boolean.valueOf( bRC );
  }

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

  public static String rtrim( ScriptEngine actualContext, Bindings actualObject, Object[] ArgList,
    Object FunctionContext ) {
    try {
      if ( ArgList.length == 1 ) {
        if ( isNull( ArgList[0] ) ) {
          return null;
        } else if ( isUndefined( ArgList[0] ) ) {
          return (String) undefinedValue;
        }
        String strValueToTrim = (String) ArgList[0];
        return strValueToTrim.replaceAll( "\\s+$", "" );
      } else {

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