source/core-developers/conditionalvisitor-validator.md

---
layout: default
title: conditionalvisitor validator
parent:
    title: Validation
    url: validation.html
---

# conditionalvisitor validator
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## Description

The ConditionalVisitorFieldValidator will forward validation to the VisitorFieldValidator only if the expression 
will evaluate to true.

## Parameters

- `expression` - an OGNL expression which should evaluate to true to pass validation to the VisitorFieldValidator.

## Examples

```xml
<field name="colleaguePosition">
    <field-validator type="conditionalvisitor">
        <param name="expression">reason == 'colleague' and colleaguePositionID == 'OTHER'</param>
        <message>You must select reason Colleague and position Other</message>
    </field-validator>
</field>
```