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IsNull
IsNull¶
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.
Also see NotNull.
Applies to | property or method |
Options | |
Class | Symfony\Component\Validator\Constraints\IsNull |
Validator | Symfony\Component\Validator\Constraints\IsNullValidator |
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:
- Annotations
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// src/AppBundle/Entity/Author.php namespace AppBundle\Entity; use Symfony\Component\Validator\Constraints as Assert; class Author { /** * @Assert\IsNull() */ protected $firstName; }
- YAML
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# src/AppBundle/Resources/config/validation.yml AppBundle\Entity\Author: properties: firstName: - 'IsNull': ~
- XML
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<!-- src/AppBundle/Resources/config/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 http://symfony.com/schema/dic/constraint-mapping/constraint-mapping-1.0.xsd"> <class name="AppBundle\Entity\Author"> <property name="firstName"> <constraint name="IsNull" /> </property> </class> </constraint-mapping>
- PHP
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// src/AppBundle/Entity/Author.php namespace AppBundle\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\IsNull()); } }
This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.