Null
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Null
Validates that a value is exactly equal to null
. To force that a property
is simply blank (blank string or null
), see the Blank
constraint. To ensure that a property is not null, see NotNull.
Applies to | property or method |
Options | |
Class | Null |
Validator | NullValidator |
Basic Usage
If, for some reason, you wanted to ensure that the firstName
property
of an Author
class exactly equal to null
, you could do the following:
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# src/Acme/BlogBundle/Resources/config/validation.yml
Acme\BlogBundle\Entity\Author:
properties:
firstName:
- 'Null': ~
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// src/Acme/BlogBundle/Entity/Author.php
namespace Acme\BlogBundle\Entity;
use Symfony\Component\Validator\Constraints as Assert;
class Author
{
/**
* @Assert\Null()
*/
protected $firstName;
}
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<!-- src/Acme/BlogBundle/Resources/config/validation.xml -->
<class name="Acme\BlogBundle\Entity\Author">
<property name="firstName">
<constraint name="Null" />
</property>
</class>
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// src/Acme/BlogBundle/Entity/Author.php
namespace Acme\BlogBundle\Entity;
use Symfony\Component\Validator\Mapping\ClassMetadata;
use Symfony\Component\Validator\Constraints as Assert;
class Author
{
public static function loadValidatorMetadata(ClassMetadata $metadata)
{
$metadata->addPropertyConstraint('firstName', Assert\Null());
}
}
This work, including the code samples, is licensed under a
Creative Commons BY-SA 3.0
license.