Validates that a value is blank, defined as equal to a blank string or equal
to null
. To force that a value strictly be equal to null
, see the
:doc:`/reference/constraints/Null` constraint. To force that a value is not
blank, see :doc:`/reference/constraints/NotBlank`.
If, for some reason, you wanted to ensure that the firstName
property
of an Author
class were blank, you could do the following:
.. configuration-block:: .. code-block:: yaml # src/BlogBundle/Resources/config/validation.yml Acme\BlogBundle\Entity\Author: properties: firstName: - Blank: ~ .. code-block:: php-annotations // src/Acme/BlogBundle/Entity/Author.php namespace Acme\BlogBundle\Entity; use Symfony\Component\Validator\Constraints as Assert; class Author { /** * @Assert\Blank() */ protected $firstName; } .. code-block:: xml <!-- src/Acme/BlogBundle/Resources/config/validation.xml --> <class name="Acme\BlogBundle\Entity\Author"> <property name="firstName"> <constraint name="Blank" /> </property> </class> .. code-block:: php // 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', new Assert\Blank()); } }
type: string
default: This value should be blank
This is the message that will be shown if the value is not blank.