The Validator Component
Edit this pageThe Validator Component
The Validator component provides tools to validate values following the JSR-303 Bean Validation specification.
Installation
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$ composer require symfony/validatorNote
If you install this component outside of a Symfony application, you must
require the vendor/autoload.php file in your code to enable the class
autoloading mechanism provided by Composer. Read
this article for more details.
Usage
See also
This article explains how to use the Validator features as an independent component in any PHP application. Read the Validation article to learn about how to validate data and entities in Symfony applications.
The Validator component behavior is based on two concepts:
- Constraints, which define the rules to be validated;
- Validators, which are the classes that contain the actual validation logic.
The following example shows how to validate that a string is at least 10 characters long:
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use Symfony\Component\Validator\Constraints\Length;
use Symfony\Component\Validator\Constraints\NotBlank;
use Symfony\Component\Validator\Validation;
$validator = Validation::createValidator();
$violations = $validator->validate('Bernhard', [
new Length(['min' => 10]),
new NotBlank(),
]);
if (0 !== count($violations)) {
// there are errors, now you can show them
foreach ($violations as $violation) {
echo $violation->getMessage().'<br>';
}
}The validate() method returns the list of violations as an object that
implements ConstraintViolationListInterface.
If you have lots of validation errors, you can filter them by error code:
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use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity;
$violations = $validator->validate(/* ... */);
if (0 !== count($violations->findByCodes(UniqueEntity::NOT_UNIQUE_ERROR))) {
// handle this specific error (display some message, send an email, etc.)
}Retrieving a Validator Instance
The Validator object (that implements ValidatorInterface) is the main access point of the Validator component. To create a new instance of it, it's recommended to use the Validation class:
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use Symfony\Component\Validator\Validation;
$validator = Validation::createValidator();This $validator object can validate simple variables such as strings, numbers
and arrays, but it can't validate objects. To do so, configure the
Validator as explained in the next sections.
Learn More
- Metadata
- Loading Resources
- Validation
- How to Create a Custom Validation Constraint
- How to Apply only a Subset of all Your Validation Constraints (Validation Groups)
- How to Validate Raw Values (Scalar Values and Arrays)
- How to Sequentially Apply Validation Groups
- How to Handle Different Error Levels
- How to Translate Validation Constraint Messages
