Part Validation Examples

Part validation allows you to enforce rules on the values entered by the user. Validation is configured in the Advanced tab of the part using:

• Set validation error via — selects the validation method

• Validation error — contains the rule and the message shown when the rule fails

You can reference the value of any part using:

#REPLACE-PARTVALUE-<InternalName>||#

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Validation Methods Overview

Method	Capabilities	Typical Use Cases
Plain text	Valid when the field contains at least one character	Simple “field cannot be empty” checks
NCalc	Expression-based logic, string comparison, date comparison, math	Dates, numeric logic, conditional checks
JavaScript	Full scripting engine with conditional logic and custom error messages	Complex rules, multi-part validation, document template validation

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Validation Examples

Below are common validation scenarios with examples for date logic, comparisons, and required fields.

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1. Compare two fields (must be equal)

Scenario: Part FieldTwo must match the value of FieldOne.

Set validation error via: JavaScript

Validation error:

if (#REPLACE-PARTVALUE-FieldOne||# !== #REPLACE-PARTVALUE-FieldTwo||#)
    return 'Field one must be equal to field two';

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2. Compare dates (one date must be after another)

Scenario:

• DateToCompareTo contains a reference date (possibly filled via a workflow).

• DateAfterDateToCompareWith must be a later date.

Default value for today (reference date)

Default value type: NCalc Default value:

FORMAT('{0:yyyyMMdd}', NOW())

Validation rule

Set validation error via: JavaScript Validation error:

if (#REPLACE-PARTVALUE-DateAfterDateToCompareWith||# < #REPLACE-PARTVALUE-DateToCompareTo||#)
    return 'Date must be after the comparison date';

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3. Date must be in the future

Scenario: The entered date must be today or later.

Set validation error via: NCalc Validation error:

IIF(
    '#REPLACE-PARTVALUE-DateAfterToday||#' < FORMAT('{0:yyyyMMdd}', NOW()),
    'Date must be after today',
    ''
)

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4. Number must not be negative

Scenario: The part value must be zero or higher.

Set validation error via: JavaScript Validation error:

var thenumber = Number(#REPLACE-PARTVALUE-nummer||#);

if (thenumber && thenumber < 0)
    return "Only positive numbers allowed";

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5. Display message when None is selected

Scenario:

When the field is a multi-select, and the option 'None of the above' is selected, we want to show a text that no other entries can be selected. THis message is only shown when another entry is selected.

Set validation error via: Javascript

Validation script:

var message_nl = "'Geen van bovenstaande' kan niet gecombineerd worden met andere antwoordopties.";

var message_en = "'None of the above' cannot be combined with other answer options.";

var value = cleanValue(#REPLACE-PARTVALUE-gdpr_nature_category_sensitive||value#);

var noneOfTheAbove = value.indexOf('None of the above') >= 0;

var selectedCount = value.split('||').length;

if (noneOfTheAbove && (selectedCount > 1)) {

// locale = CommonInterface.getCurrentLanguageCulture(); // doesn't exist

return message_nl + " / " + message_en;

if (locale == 'nl-BE') {

return message_nl;

}

return message_en;

}

function cleanValue(value) {

// little hack needed, because in the resulting value string, there were sometimes empty values for some reason

value = value.replace("||||", "||");

if (value.indexOf('||') == 0) {

value = value.substring(2, value.length);

}

if (value.indexOf('||') == value.length - 2) {

value = value.substring(0, value.length - 2);

}

return value;

}

Validation for Document Templates

Document Templates often require validation across multiple document parts. Using JavaScript validation allows you to check multiple fields and return detailed error messages.

Validation scripts for documents return an object:

{
  success: <true/false>,
  errormessage: "<message>",
  errormessages: {
      <InternalName>: "<message>",
      ...
  }
}

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5. Make two document fields required

Fields:

• Doc_Category

• Doc_Versie

Set validation error via: JavaScript Validation error:

var toreturn = { success: true };

var parts = JSON.parse(g_data_string).parts;

var category = parts.filter(p => p.internalname === "Doc_Category").map(p => p.value).join("");
var version = parts.filter(p => p.internalname === "Doc_Versie").map(p => p.value).join("");

if (!category || !version) {

    toreturn.success = false;
    toreturn.errormessages = {};

    if (!category && !version) {
        toreturn.errormessage = "'Category' and 'Version' are required";
    } else if (!category) {
        toreturn.errormessage = "'Category' is required";
    } else if (!version) {
        toreturn.errormessage = "'Version' is required";
    }

    if (!category) {
        toreturn.errormessages.Doc_Category = "A value is required";
    }

    if (!version) {
        toreturn.errormessages.Doc_Versie = "A value is required";
    }
}

return toreturn;

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6. Make three document fields required

Fields:

• Doc_Category

• Doc_Version

• Doc_Version_date

Set validation error via: JavaScript Validation error:

var toreturn = { success: true };

var parts = JSON.parse(g_data_string).parts;

var category     = parts.filter(p => p.internalname === "Doc_Category").map(p => p.value).join("");
var version      = parts.filter(p => p.internalname === "Doc_Version").map(p => p.value).join("");
var versiondate  = parts.filter(p => p.internalname === "Doc_Version_date").map(p => p.value).join("");

if (!category || !version || !versiondate) {

    toreturn.success = false;
    toreturn.errormessages = {};

    var missingfields = [];

    if (!category) {
        missingfields.push("Category");
        toreturn.errormessages.Doc_Category = "A value is required";
    }

    if (!version) {
        missingfields.push("Version number");
        toreturn.errormessages.Doc_Version = "A value is required";
    }

    if (!versiondate) {
        missingfields.push("Version date");
        toreturn.errormessages.Doc_Version_date = "A value is required";
    }

    toreturn.errormessage =
        "One or more fields are required: " +
        missingfields.map(fld => "'" + fld + "'").join(", ");
}

return toreturn;

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Summary

This chapter provides clear examples for:

• field-to-field comparisons

• date validation

• numeric validation

• multi-field validation for document templates

• differences between Plain text, NCalc, and JavaScript validation

By applying these patterns, you can enforce simple and advanced validation logic consistently across your templates.