Validates that a given string length is between some minimum and maximum value.
To verify that the firstName field length of a class is between 2
and 50, you might add the following:
.. configuration-block::
.. code-block:: php-attributes
// 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 string $firstName;
}
.. code-block:: yaml
# config/validator/validation.yaml
App\Entity\Participant:
properties:
firstName:
- 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'
.. code-block:: xml
<!-- config/validator/validation.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<constraint-mapping xmlns="http://symfony.com/schema/dic/constraint-mapping"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://symfony.com/schema/dic/constraint-mapping https://symfony.com/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd">
<class name="App\Entity\Participant">
<property name="firstName">
<constraint name="Length">
<option name="min">2</option>
<option name="max">50</option>
<option name="minMessage">
Your first name must be at least {{ limit }} characters long
</option>
<option name="maxMessage">
Your first name cannot be longer than {{ limit }} characters
</option>
</constraint>
</property>
</class>
</constraint-mapping>
.. code-block:: php
// src/Entity/Participant.php
namespace App\Entity;
use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\Validator\Mapping\ClassMetadata;
class Participant
{
// ...
public static function loadValidatorMetadata(ClassMetadata $metadata): void
{
$metadata->addPropertyConstraint('firstName', new 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',
]));
}
}
type: string default: UTF-8
The charset to be used when computing value's length with the :phpfunction:`mb_check_encoding` and :phpfunction:`mb_strlen` PHP functions.
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 |
type: string default: Length::COUNT_CODEPOINTS
The character count unit to use for the length check. By default :phpfunction:`mb_strlen` is used, which counts Unicode code points.
Can be one of the following constants of the :class:`Symfony\\Component\\Validator\\Constraints\\Length` class:
COUNT_BYTES: Uses :phpfunction:`strlen` counting the length of the string in bytes.COUNT_CODEPOINTS: Uses :phpfunction:`mb_strlen` counting the length of the string in Unicode code points. This was the sole behavior until Symfony 6.2 and is the default since Symfony 6.3. Simple (multibyte) Unicode characters count as 1 character, while for example ZWJ sequences of composed emojis count as multiple characters.COUNT_GRAPHEMES: Uses :phpfunction:`grapheme_strlen` counting the length of the string in graphemes, i.e. even emojis and ZWJ sequences of composed emojis count as 1 character.
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.
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 |
{{ value_length }} |
The current value's length |
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.
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 |
{{ value_length }} |
The current value's length |
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.
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 |
{{ value_length }} |
The current value's length |