Validate array string lengths

The Search/arrayStringLength extension checks each item in a JSON array and confirms that every item is a string, is not null or undefined, is not blank after trimming, and stays within the configured minimum and maximum string length.

This is useful when a journey needs to validate search results, table values, API-derived arrays, or extracted text collections before continuing with later checks that depend on clean string data.

Parameters:

• Array required, a JSON string representing the array of values to validate. The source code parses this input with JSON.parse(Array), so pass a valid JSON array string such as ["hello","world"];
• MinLength required, the minimum allowed string length. This value is compared with each item's length;
• MaxLength required, the maximum allowed string length. This value is compared with each item's length;

How to apply this to your journey

Use the extension in a journey by calling Search/arrayStringLength with the execute command. Pass each value to the matching extension input using as Array, as MinLength, and as MaxLength.

execute "Search/arrayStringLength" using '["hello","world","sample"]' as Array, "2" as MinLength and "10" as MaxLength returning $response

execute "Search/arrayStringLength" using '["hello","world",null,"!","this is a test",""]' as Array, "2" as MinLength and "10" as MaxLength returning $response

You can also pass journey variables into the extension when the array or length values are prepared earlier in the journey.

execute "Search/arrayStringLength" using "$arrayValues" as Array, "$minLength" as MinLength and "$maxLength" as MaxLength returning $response

store value '["hello","world","sample"]' in $arrayValues
store value "2" in $minLength
store value "10" in $maxLength
execute "Search/arrayStringLength" using "$arrayValues" as Array, "$minLength" as MinLength and "$maxLength" as MaxLength returning $response

Example successful output:

All items meet the length requirements and are not null.

Example validation error output:

Errors found:
Item at index 2 is null or undefined.
Item at index 3 is shorter than the minimum length of 2.
Item at index 4 is longer than the maximum length of 10.
Item at index 5 is an empty string.

This extension does not require any external resource.

The extension should be configured as:

• Run asynchronously: No
• Scope: Global

Add the extension to your Virtuoso instance

Select the domain that matches your Virtuoso account.

function assertLengthAndNoNulls(array, minLength, maxLength) {
  const errors = [];

  array.forEach((item, index) => {
    if (item === null || item === undefined) {
      errors.push(`Item at index ${index} is null or undefined.`);
    } else if (typeof item !== 'string') {
      errors.push(`Item at index ${index} is not a string.`);
    } else if (item.trim() === '') {
      errors.push(`Item at index ${index} is an empty string.`);
    } else if (item.length < minLength) {
      errors.push(`Item at index ${index} is shorter than the minimum length of ${minLength}.`);
    } else if (item.length > maxLength) {
      errors.push(`Item at index ${index} is longer than the maximum length of ${maxLength}.`);
    }
  });

  if (errors.length > 0) {
    return { success: false, errors: errors };
  } else {
    return { success: true, message: 'All items meet the length requirements and are not null.' };
  }
}

// Example usage:
const array = JSON.parse(Array);
const minLength = MinLength;
const maxLength = MaxLength;
const result = assertLengthAndNoNulls(array, minLength, maxLength);

if (result.success) {
  console.log(result.message);
  return result.message;
} else {
  console.error('Errors found:');
  result.errors.forEach(error => console.error(error));
  return `Errors found:
${result.errors.join('
')}`;
}