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Front cover of the Symfony 5: The Fast Track book

Symfony 5: The Fast Track

A new book to learn about developing modern Symfony 5 applications.

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WARNING: You are browsing the documentation for Symfony 2.4 which is not maintained anymore. Consider upgrading your projects to Symfony 4.3.

Blank

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Blank

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 Null constraint. To force that a value is not blank, see NotBlank.

Applies to property or method
Options
Class Blank
Validator BlankValidator

Basic Usage

If, for some reason, you wanted to ensure that the firstName property of an Author class were blank, you could do the following:

  • YAML
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    # src/Acme/BlogBundle/Resources/config/validation.yml
Acme\BlogBundle\Entity\Author:
    properties:
        firstName:
            - Blank: ~
  • Annotations
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    // src/Acme/BlogBundle/Entity/Author.php
namespace Acme\BlogBundle\Entity;

use Symfony\Component\Validator\Constraints as Assert;

class Author
{
    /**
     * @Assert\Blank()
     */
    protected $firstName;
}
  • XML
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    <!-- src/Acme/BlogBundle/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="Acme\BlogBundle\Entity\Author">
        <property name="firstName">
            <constraint name="Blank" />
        </property>
    </class>
</constraint-mapping>
  • PHP
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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', new Assert\Blank());
    }
}

Options

message

type: string default: This value should be blank.

This is the message that will be shown if the value is not blank.

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.