Length
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Validates that a given string length is between some minimum and maximum value.
| Applies to | property or method |
| Class | Length |
| Validator | LengthValidator |
Basic Usage
To verify that the firstName field length of a class is between 2
and 50, you might add the following:
- Attributes
- YAML
- XML
- PHP
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// src/Entity/Participant.php
namespace App\Entity;
use Symfony\Component\Validator\Constraints as Assert;
class Participant
{
#[Assert\Length(
min: 2,
max: 50,
minMessage: 'Your first name must be at least {{ limit }} characters long',
maxMessage: 'Your first name cannot be longer than {{ limit }} characters',
)]
protected $firstName;
}Note
As with most of the other constraints, null is
considered a valid value. This is to allow the use of optional values.
If the value is mandatory, a common solution is to combine this constraint
with NotNull.
Options
charset
type: string default: UTF-8
The charset to be used when computing value's length with the mb_check_encoding and mb_strlen PHP functions.
charsetMessage
type: string default: This value does not match the expected {{ charset }} charset.
The message that will be shown if the value is not using the given charset.
You can use the following parameters in this message:
| Parameter | Description |
|---|---|
{{ charset }} |
The expected charset |
{{ value }} |
The current (invalid) value |
exactly
type: integer
This option is the exact length value. Validation will fail if the given value's length is not exactly equal to this value.
Note
This option is the one being set by default when using the Length constraint
without passing any named argument to it. This means that for example,
#[Assert\Length(20)] and #[Assert\Length(exactly: 20)] are equivalent.
exactMessage
type: string default: This value should have exactly {{ limit }} characters.
The message that will be shown if min and max values are equal and the underlying value's length is not exactly this value.
You can use the following parameters in this message:
| Parameter | Description |
|---|---|
{{ limit }} |
The exact expected length |
{{ value }} |
The current (invalid) value |
groups
type: array | string
It defines the validation group or groups of this constraint. Read more about validation groups.
max
type: integer
This option is the "max" length value. Validation will fail if the given value's length is greater than this max value.
This option is required when the min option is not defined.
maxMessage
type: string default: This value is too long. It should have {{ limit }} characters or less.
The message that will be shown if the underlying value's length is more than the max option.
You can use the following parameters in this message:
| Parameter | Description |
|---|---|
{{ limit }} |
The expected maximum length |
{{ value }} |
The current (invalid) value |
min
type: integer
This option is the "min" length value. Validation will fail if the given value's length is less than this min value.
This option is required when the max option is not defined.
It is important to notice that null values are considered
valid no matter if the constraint requires a minimum length. Validators
are triggered only if the value is not null.
minMessage
type: string default: This value is too short. It should have {{ limit }} characters or more.
The message that will be shown if the underlying value's length is less than the min option.
You can use the following parameters in this message:
| Parameter | Description |
|---|---|
{{ limit }} |
The expected minimum length |
{{ value }} |
The current (invalid) value |
normalizer
type: a PHP callable default: null
This option allows to define the PHP callable applied to the given value before checking if it is valid.
For example, you may want to pass the 'trim' string to apply the
trim PHP function in order to ignore leading and trailing
whitespace during validation.
payload
type: mixed default: null
This option can be used to attach arbitrary domain-specific data to a constraint. The configured payload is not used by the Validator component, but its processing is completely up to you.
For example, you may want to use several error levels to present failed constraints differently in the front-end depending on the severity of the error.
