source/core-developers/short-validator.md

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

# short validator
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* Will be replaced with the ToC, excluding a header
{:toc}

## Description

Field Validator that checks if the short specified is within a certain range.

## Parameters

- `fieldName` - The field name this validator is validating. Required if using Plain-Validator Syntax otherwise not required.
- `min` - the minimum value (if none is specified, it will not be checked).
- `max` - the maximum value (if none is specified, it will not be checked).
- `parse` - if set to true, minExpression and maxExpression will be evaluated to find min/max.
- `minExpression` - expression to calculate the minimum value (if none is specified, it will not be checked).
- `maxExpression` - expression to calculate the maximum value (if none is specified, it will not be checked).

You can either use the `min` / `max` value or `minExpression` / `maxExpression` (when `parse` is set to `true`) - using 
expression can be slightly slower, see the example below.

> Warning: do not use `${minExpression}` and `${maxExpression}` as an expression as this will turn into infinitive loop!

## Examples

```xml
<validators>
    <!-- Plain Validator Syntax -->
    <validator type="short">
        <param name="fieldName">age</param>
        <param name="min">20</param>
        <param name="max">50</param>
        <message>Age needs to be between ${min} and ${max}</message>
    </validator>
 
    <!-- Field Validator Syntax -->
    <field name="age">
        <field-validator type="short">
            <param name="min">20</param>
            <param name="max">50</param>
            <message>Age needs to be between ${min} and ${max}</message>
        </field-validator>
    </field>
 
    <!-- Field Validator Syntax with expression -->
    <field name="age">
        <field-validator type="short">
            <param name="minExpression">${minValue}</param> <!-- will be evaluated as: Short getMinValue() -->
            <param name="maxExpression">${maxValue}</param> <!-- will be evaluated as: Short getMaxValue() -->
            <message>Age needs to be between ${min} and ${max}</message>
        </field-validator>
    </field>
</validators>
```