.. index:: single: Validation
Validation is a very common task in web applications. Data entered in forms needs to be validated. Data also needs to be validated before it is written into a database or passed to a web service.
Symfony2 ships with a Validator component that makes this task easy and transparent. This component is based on the JSR303 Bean Validation specification.
.. index:: single: Validation; The basics
The best way to understand validation is to see it in action. To start, suppose you've created a plain-old-PHP object that you need to use somewhere in your application:
// src/Acme/BlogBundle/Entity/Author.php
namespace Acme\BlogBundle\Entity;
class Author
{
public $name;
}
So far, this is just an ordinary class that serves some purpose inside your application. The goal of validation is to tell you whether or not the data of an object is valid. For this to work, you'll configure a list of rules (called :ref:`constraints <validation-constraints>`) that the object must follow in order to be valid. These rules can be specified via a number of different formats (YAML, XML, annotations, or PHP).
For example, to guarantee that the $name property is not empty, add the
following:
.. configuration-block::
.. code-block:: yaml
# src/Acme/BlogBundle/Resources/config/validation.yml
Acme\BlogBundle\Entity\Author:
properties:
name:
- NotBlank: ~
.. code-block:: php-annotations
// src/Acme/BlogBundle/Entity/Author.php
// ...
use Symfony\Component\Validator\Constraints as Assert;
class Author
{
/**
* @Assert\NotBlank()
*/
public $name;
}
.. code-block:: xml
<!-- 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="name">
<constraint name="NotBlank" />
</property>
</class>
</constraint-mapping>
.. code-block:: php
// src/Acme/BlogBundle/Entity/Author.php
// ...
use Symfony\Component\Validator\Mapping\ClassMetadata;
use Symfony\Component\Validator\Constraints\NotBlank;
class Author
{
public $name;
public static function loadValidatorMetadata(ClassMetadata $metadata)
{
$metadata->addPropertyConstraint('name', new NotBlank());
}
}
Tip
Protected and private properties can also be validated, as well as "getter" methods (see :ref:`validator-constraint-targets`).
.. index:: single: Validation; Using the validator
Next, to actually validate an Author object, use the validate method
on the validator service (class :class:`Symfony\\Component\\Validator\\Validator`).
The job of the validator is easy: to read the constraints (i.e. rules)
of a class and verify whether or not the data on the object satisfies those
constraints. If validation fails, a non-empty list of errors
(class :class:`Symfony\\Component\\Validator\\ConstraintViolationList`) is
returned. Take this simple example from inside a controller:
// ...
use Symfony\Component\HttpFoundation\Response;
use Acme\BlogBundle\Entity\Author;
public function indexAction()
{
$author = new Author();
// ... do something to the $author object
$validator = $this->get('validator');
$errors = $validator->validate($author);
if (count($errors) > 0) {
/*
* Uses a __toString method on the $errors variable which is a
* ConstraintViolationList object. This gives us a nice string
* for debugging
*/
$errorsString = (string) $errors;
return new Response($errorsString);
}
return new Response('The author is valid! Yes!');
}
If the $name property is empty, you will see the following error
message:
Acme\BlogBundle\Author.name:
This value should not be blank
If you insert a value into the name property, the happy success message
will appear.
Tip
Most of the time, you won't interact directly with the validator
service or need to worry about printing out the errors. Most of the time,
you'll use validation indirectly when handling submitted form data. For
more information, see the :ref:`book-validation-forms`.
You could also pass the collection of errors into a template.
if (count($errors) > 0) {
return $this->render('AcmeBlogBundle:Author:validate.html.twig', array(
'errors' => $errors,
));
}Inside the template, you can output the list of errors exactly as needed:
.. configuration-block::
.. code-block:: html+jinja
{# src/Acme/BlogBundle/Resources/views/Author/validate.html.twig #}
<h3>The author has the following errors</h3>
<ul>
{% for error in errors %}
<li>{{ error.message }}</li>
{% endfor %}
</ul>
.. code-block:: html+php
<!-- src/Acme/BlogBundle/Resources/views/Author/validate.html.php -->
<h3>The author has the following errors</h3>
<ul>
<?php foreach ($errors as $error): ?>
<li><?php echo $error->getMessage() ?></li>
<?php endforeach; ?>
</ul>
Note
Each validation error (called a "constraint violation"), is represented by a :class:`Symfony\\Component\\Validator\\ConstraintViolation` object.
.. index:: single: Validation; Validation with forms
The validator service can be used at any time to validate any object.
In reality, however, you'll usually work with the validator indirectly
when working with forms. Symfony's form library uses the validator service
internally to validate the underlying object after values have been submitted.
The constraint violations on the object are converted into FieldError
objects that can easily be displayed with your form. The typical form submission
workflow looks like the following from inside a controller:
// ...
use Acme\BlogBundle\Entity\Author;
use Acme\BlogBundle\Form\AuthorType;
use Symfony\Component\HttpFoundation\Request;
public function updateAction(Request $request)
{
$author = new Author();
$form = $this->createForm(new AuthorType(), $author);
$form->handleRequest($request);
if ($form->isValid()) {
// the validation passed, do something with the $author object
return $this->redirect($this->generateUrl(...));
}
return $this->render('BlogBundle:Author:form.html.twig', array(
'form' => $form->createView(),
));
}
Note
This example uses an AuthorType form class, which is not shown here.
For more information, see the :doc:`Forms </book/forms>` chapter.
.. index:: pair: Validation; Configuration
The Symfony2 validator is enabled by default, but you must explicitly enable annotations if you're using the annotation method to specify your constraints:
.. configuration-block::
.. code-block:: yaml
# app/config/config.yml
framework:
validation: { enable_annotations: true }
.. code-block:: xml
<!-- app/config/config.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:framework="http://symfony.com/schema/dic/symfony"
xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd
http://symfony.com/schema/dic/symfony http://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
<framework:config>
<framework:validation enable-annotations="true" />
</framework:config>
</container>
.. code-block:: php
// app/config/config.php
$container->loadFromExtension('framework', array(
'validation' => array(
'enable_annotations' => true,
),
));
.. index:: single: Validation; Constraints
The validator is designed to validate objects against constraints (i.e.
rules). In order to validate an object, simply map one or more constraints
to its class and then pass it to the validator service.
Behind the scenes, a constraint is simply a PHP object that makes an assertive statement. In real life, a constraint could be: "The cake must not be burned". In Symfony2, constraints are similar: they are assertions that a condition is true. Given a value, a constraint will tell you whether or not that value adheres to the rules of the constraint.
Symfony2 packages a large number of the most commonly-needed constraints:
You can also create your own custom constraints. This topic is covered in the ":doc:`/cookbook/validation/custom_constraint`" article of the cookbook.
.. index:: single: Validation; Constraints configuration
Some constraints, like :doc:`NotBlank </reference/constraints/NotBlank>`,
are simple whereas others, like the :doc:`Choice </reference/constraints/Choice>`
constraint, have several configuration options available. Suppose that the
Author class has another property, gender that can be set to either
"male" or "female":
.. configuration-block::
.. code-block:: yaml
# src/Acme/BlogBundle/Resources/config/validation.yml
Acme\BlogBundle\Entity\Author:
properties:
gender:
- Choice: { choices: [male, female], message: Choose a valid gender. }
.. code-block:: php-annotations
// src/Acme/BlogBundle/Entity/Author.php
use Symfony\Component\Validator\Constraints as Assert;
class Author
{
/**
* @Assert\Choice(
* choices = { "male", "female" },
* message = "Choose a valid gender."
* )
*/
public $gender;
}
.. code-block:: xml
<!-- 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="gender">
<constraint name="Choice">
<option name="choices">
<value>male</value>
<value>female</value>
</option>
<option name="message">Choose a valid gender.</option>
</constraint>
</property>
</class>
</constraint-mapping>
.. code-block:: php
// src/Acme/BlogBundle/Entity/Author.php
// ...
use Symfony\Component\Validator\Mapping\ClassMetadata;
use Symfony\Component\Validator\Constraints\Choice;
class Author
{
public $gender;
public static function loadValidatorMetadata(ClassMetadata $metadata)
{
$metadata->addPropertyConstraint('gender', new Choice(array(
'choices' => array('male', 'female'),
'message' => 'Choose a valid gender.',
)));
}
}
The options of a constraint can always be passed in as an array. Some constraints,
however, also allow you to pass the value of one, "default", option in place
of the array. In the case of the Choice constraint, the choices
options can be specified in this way.
.. configuration-block::
.. code-block:: yaml
# src/Acme/BlogBundle/Resources/config/validation.yml
Acme\BlogBundle\Entity\Author:
properties:
gender:
- Choice: [male, female]
.. code-block:: php-annotations
// src/Acme/BlogBundle/Entity/Author.php
// ...
use Symfony\Component\Validator\Constraints as Assert;
class Author
{
/**
* @Assert\Choice({"male", "female"})
*/
protected $gender;
}
.. code-block:: xml
<!-- 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="gender">
<constraint name="Choice">
<value>male</value>
<value>female</value>
</constraint>
</property>
</class>
</constraint-mapping>
.. code-block:: php
// src/Acme/BlogBundle/Entity/Author.php
// ...
use Symfony\Component\Validator\Mapping\ClassMetadata;
use Symfony\Component\Validator\Constraints\Choice;
class Author
{
protected $gender;
public static function loadValidatorMetadata(ClassMetadata $metadata)
{
$metadata->addPropertyConstraint(
'gender',
new Choice(array('male', 'female'))
);
}
}
This is purely meant to make the configuration of the most common option of a constraint shorter and quicker.
If you're ever unsure of how to specify an option, either check the API documentation for the constraint or play it safe by always passing in an array of options (the first method shown above).
For information on translating the constraint messages, see :ref:`book-translation-constraint-messages`.
.. index:: single: Validation; Constraint targets
Constraints can be applied to a class property (e.g. name) or a public
getter method (e.g. getFullName). The first is the most common and easy
to use, but the second allows you to specify more complex validation rules.
.. index:: single: Validation; Property constraints
Validating class properties is the most basic validation technique. Symfony2
allows you to validate private, protected or public properties. The next
listing shows you how to configure the $firstName property of an Author
class to have at least 3 characters.
.. configuration-block::
.. code-block:: yaml
# src/Acme/BlogBundle/Resources/config/validation.yml
Acme\BlogBundle\Entity\Author:
properties:
firstName:
- NotBlank: ~
- Length:
min: 3
.. code-block:: php-annotations
// Acme/BlogBundle/Entity/Author.php
// ...
use Symfony\Component\Validator\Constraints as Assert;
class Author
{
/**
* @Assert\NotBlank()
* @Assert\Length(min = "3")
*/
private $firstName;
}
.. code-block:: xml
<!-- 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="NotBlank" />
<constraint name="Length">
<option name="min">3</option>
</constraint>
</property>
</class>
</constraint-mapping>
.. code-block:: php
// src/Acme/BlogBundle/Entity/Author.php
// ...
use Symfony\Component\Validator\Mapping\ClassMetadata;
use Symfony\Component\Validator\Constraints\NotBlank;
use Symfony\Component\Validator\Constraints\Length;
class Author
{
private $firstName;
public static function loadValidatorMetadata(ClassMetadata $metadata)
{
$metadata->addPropertyConstraint('firstName', new NotBlank());
$metadata->addPropertyConstraint(
'firstName',
new Length(array("min" => 3)));
}
}
.. index:: single: Validation; Getter constraints
Constraints can also be applied to the return value of a method. Symfony2 allows you to add a constraint to any public method whose name starts with "get", "is" or "has". In this guide, these types of methods are referred to as "getters".
.. versionadded:: 2.5
Support for methods starting with ``has`` was introduced in Symfony 2.5.
The benefit of this technique is that it allows you to validate your object
dynamically. For example, suppose you want to make sure that a password field
doesn't match the first name of the user (for security reasons). You can
do this by creating an isPasswordLegal method, and then asserting that
this method must return true:
.. configuration-block::
.. code-block:: yaml
# src/Acme/BlogBundle/Resources/config/validation.yml
Acme\BlogBundle\Entity\Author:
getters:
passwordLegal:
- "True": { message: "The password cannot match your first name" }
.. code-block:: php-annotations
// src/Acme/BlogBundle/Entity/Author.php
// ...
use Symfony\Component\Validator\Constraints as Assert;
class Author
{
/**
* @Assert\True(message = "The password cannot match your first name")
*/
public function isPasswordLegal()
{
// return true or false
}
}
.. code-block:: xml
<!-- 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">
<getter property="passwordLegal">
<constraint name="True">
<option name="message">The password cannot match your first name</option>
</constraint>
</getter>
</class>
</constraint-mapping>
.. code-block:: php
// src/Acme/BlogBundle/Entity/Author.php
// ...
use Symfony\Component\Validator\Mapping\ClassMetadata;
use Symfony\Component\Validator\Constraints\True;
class Author
{
public static function loadValidatorMetadata(ClassMetadata $metadata)
{
$metadata->addGetterConstraint('passwordLegal', new True(array(
'message' => 'The password cannot match your first name',
)));
}
}
Now, create the isPasswordLegal() method, and include the logic you need:
public function isPasswordLegal()
{
return $this->firstName != $this->password;
}
Note
The keen-eyed among you will have noticed that the prefix of the getter ("get", "is" or "has") is omitted in the mapping. This allows you to move the constraint to a property with the same name later (or vice versa) without changing your validation logic.
Some constraints apply to the entire class being validated. For example, the :doc:`Callback </reference/constraints/Callback>` constraint is a generic constraint that's applied to the class itself. When that class is validated, methods specified by that constraint are simply executed so that each can provide more custom validation.
So far, you've been able to add constraints to a class and ask whether or not that class passes all of the defined constraints. In some cases, however, you'll need to validate an object against only some of the constraints on that class. To do this, you can organize each constraint into one or more "validation groups", and then apply validation against just one group of constraints.
For example, suppose you have a User class, which is used both when a
user registers and when a user updates their contact information later:
.. configuration-block::
.. code-block:: yaml
# src/Acme/BlogBundle/Resources/config/validation.yml
Acme\BlogBundle\Entity\User:
properties:
email:
- Email: { groups: [registration] }
password:
- NotBlank: { groups: [registration] }
- Length: { min: 7, groups: [registration] }
city:
- Length:
min: 2
.. code-block:: php-annotations
// src/Acme/BlogBundle/Entity/User.php
namespace Acme\BlogBundle\Entity;
use Symfony\Component\Security\Core\User\UserInterface;
use Symfony\Component\Validator\Constraints as Assert;
class User implements UserInterface
{
/**
* @Assert\Email(groups={"registration"})
*/
private $email;
/**
* @Assert\NotBlank(groups={"registration"})
* @Assert\Length(min=7, groups={"registration"})
*/
private $password;
/**
* @Assert\Length(min = "2")
*/
private $city;
}
.. code-block:: xml
<!-- 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\User">
<property name="email">
<constraint name="Email">
<option name="groups">
<value>registration</value>
</option>
</constraint>
</property>
<property name="password">
<constraint name="NotBlank">
<option name="groups">
<value>registration</value>
</option>
</constraint>
<constraint name="Length">
<option name="min">7</option>
<option name="groups">
<value>registration</value>
</option>
</constraint>
</property>
<property name="city">
<constraint name="Length">
<option name="min">7</option>
</constraint>
</property>
</class>
</constraint-mapping>
.. code-block:: php
// src/Acme/BlogBundle/Entity/User.php
namespace Acme\BlogBundle\Entity;
use Symfony\Component\Validator\Mapping\ClassMetadata;
use Symfony\Component\Validator\Constraints\Email;
use Symfony\Component\Validator\Constraints\NotBlank;
use Symfony\Component\Validator\Constraints\Length;
class User
{
public static function loadValidatorMetadata(ClassMetadata $metadata)
{
$metadata->addPropertyConstraint('email', new Email(array(
'groups' => array('registration'),
)));
$metadata->addPropertyConstraint('password', new NotBlank(array(
'groups' => array('registration'),
)));
$metadata->addPropertyConstraint('password', new Length(array(
'min' => 7,
'groups' => array('registration')
)));
$metadata->addPropertyConstraint(
'city',
Length(array("min" => 3)));
}
}
With this configuration, there are three validation groups:
Default- contains the constraints in the current class and all referenced classes that belong to no other group;User- equivalent to all constraints of theUserobject in theDefaultgroup;registration- contains the constraints on theemailandpasswordfields only.
To tell the validator to use a specific group, pass one or more group names
as the second argument to the validate() method:
$errors = $validator->validate($author, array('registration'));
If no groups are specified, all constraints that belong in group Default
will be applied.
Of course, you'll usually work with validation indirectly through the form library. For information on how to use validation groups inside forms, see :ref:`book-forms-validation-groups`.
.. index:: single: Validation; Validating raw values
In some cases, you want to validate your groups by steps. To do this, you can
use the GroupSequence feature. In this case, an object defines a group
sequence, which determines the order groups should be validated.
For example, suppose you have a User class and want to validate that the
username and the password are different only if all other validation passes
(in order to avoid multiple error messages).
.. configuration-block::
.. code-block:: yaml
# src/Acme/BlogBundle/Resources/config/validation.yml
Acme\BlogBundle\Entity\User:
group_sequence:
- User
- Strict
getters:
passwordLegal:
- "True":
message: "The password cannot match your username"
groups: [Strict]
properties:
username:
- NotBlank: ~
password:
- NotBlank: ~
.. code-block:: php-annotations
// src/Acme/BlogBundle/Entity/User.php
namespace Acme\BlogBundle\Entity;
use Symfony\Component\Security\Core\User\UserInterface;
use Symfony\Component\Validator\Constraints as Assert;
/**
* @Assert\GroupSequence({"User", "Strict"})
*/
class User implements UserInterface
{
/**
* @Assert\NotBlank
*/
private $username;
/**
* @Assert\NotBlank
*/
private $password;
/**
* @Assert\True(message="The password cannot match your username", groups={"Strict"})
*/
public function isPasswordLegal()
{
return ($this->username !== $this->password);
}
}
.. code-block:: xml
<!-- 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\User">
<property name="username">
<constraint name="NotBlank" />
</property>
<property name="password">
<constraint name="NotBlank" />
</property>
<getter property="passwordLegal">
<constraint name="True">
<option name="message">The password cannot match your username</option>
<option name="groups">
<value>Strict</value>
</option>
</constraint>
</getter>
<group-sequence>
<value>User</value>
<value>Strict</value>
</group-sequence>
</class>
</constraint-mapping>
.. code-block:: php
// src/Acme/BlogBundle/Entity/User.php
namespace Acme\BlogBundle\Entity;
use Symfony\Component\Validator\Mapping\ClassMetadata;
use Symfony\Component\Validator\Constraints as Assert;
class User
{
public static function loadValidatorMetadata(ClassMetadata $metadata)
{
$metadata->addPropertyConstraint(
'username',
new Assert\NotBlank()
);
$metadata->addPropertyConstraint(
'password',
new Assert\NotBlank()
);
$metadata->addGetterConstraint(
'passwordLegal',
new Assert\True(array(
'message' => 'The password cannot match your first name',
'groups' => array('Strict'),
))
);
$metadata->setGroupSequence(array('User', 'Strict'));
}
}
In this example, it will first validate all constraints in the group User
(which is the same as the Default group). Only if all constraints in
that group are valid, the second group, Strict, will be validated.
Caution!
As you have already seen in the previous section, the Default group
and the group containing the class name (e.g. User) were identical.
However, when using Group Sequences, they are no longer identical. The
Default group will now reference the group sequence, instead of all
constraints that do not belong to any group.
This means that you have to use the {ClassName} (e.g. User) group
when specifying a group sequence. When using Default, you get an
infinite recursion (as the Default group references the group
sequence, which will contain the Default group which references the
same group sequence, ...).
Imagine a User entity which can be a normal user or a premium user. When
it's a premium user, some extra constraints should be added to the user entity
(e.g. the credit card details). To dynamically determine which groups should
be activated, you can create a Group Sequence Provider. First, create the
entity and a new constraint group called Premium:
.. configuration-block::
.. code-block:: yaml
# src/Acme/DemoBundle/Resources/config/validation.yml
Acme\DemoBundle\Entity\User:
properties:
name:
- NotBlank: ~
creditCard:
- CardScheme:
schemes: [VISA]
groups: [Premium]
.. code-block:: php-annotations
// src/Acme/DemoBundle/Entity/User.php
namespace Acme\DemoBundle\Entity;
use Symfony\Component\Validator\Constraints as Assert;
class User
{
// ...
/**
* @Assert\NotBlank()
*/
private $name;
/**
* @Assert\CardScheme(
* schemes={"VISA"},
* groups={"Premium"},
* )
*/
private $creditCard;
}
.. code-block:: xml
<!-- src/Acme/DemoBundle/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\DemoBundle\Entity\User">
<property name="name">
<constraint name="NotBlank" />
</property>
<property name="creditCard">
<constraint name="CardScheme">
<option name="schemes">
<value>VISA</value>
</option>
<option name="groups">
<value>Premium</value>
</option>
</constraint>
</property>
</class>
</constraint-mapping>
.. code-block:: php
// src/Acme/DemoBundle/Entity/User.php
namespace Acme\DemoBundle\Entity;
use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\Validator\Mapping\ClassMetadata;
class User
{
private $name;
private $creditCard;
// ...
public static function loadValidatorMetadata(ClassMetadata $metadata)
{
$metadata->addPropertyConstraint('name', new Assert\NotBlank());
$metadata->addPropertyConstraint('creditCard', new Assert\CardScheme(
'schemes' => array('VISA'),
'groups' => array('Premium'),
));
}
}
Now, change the User class to implement
:class:`Symfony\\Component\\Validator\\GroupSequenceProviderInterface` and
add the
:method:`Symfony\\Component\\Validator\\GroupSequenceProviderInterface::getGroupSequence`,
which should return an array of groups to use:
// src/Acme/DemoBundle/Entity/User.php
namespace Acme\DemoBundle\Entity;
// ...
use Symfony\Component\Validator\GroupSequenceProviderInterface;
class User implements GroupSequenceProviderInterface
{
// ...
public function getGroupSequence()
{
$groups = array('User');
if ($this->isPremium()) {
$groups[] = 'Premium';
}
return $groups;
}
}
At last, you have to notify the Validator component that your User class
provides a sequence of groups to be validated:
.. configuration-block::
.. code-block:: yaml
# src/Acme/DemoBundle/Resources/config/validation.yml
Acme\DemoBundle\Entity\User:
group_sequence_provider: ~
.. code-block:: php-annotations
// src/Acme/DemoBundle/Entity/User.php
namespace Acme\DemoBundle\Entity;
// ...
/**
* @Assert\GroupSequenceProvider
*/
class User implements GroupSequenceProviderInterface
{
// ...
}
.. code-block:: xml
<!-- src/Acme/DemoBundle/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\DemoBundle\Entity\User">
<group-sequence-provider />
<!-- ... -->
</class>
</constraint-mapping>
.. code-block:: php
// src/Acme/DemoBundle/Entity/User.php
namespace Acme\DemoBundle\Entity;
// ...
use Symfony\Component\Validator\Mapping\ClassMetadata;
class User implements GroupSequenceProviderInterface
{
// ...
public static function loadValidatorMetadata(ClassMetadata $metadata)
{
$metadata->setGroupSequenceProvider(true);
// ...
}
}
So far, you've seen how you can validate entire objects. But sometimes, you just want to validate a simple value - like to verify that a string is a valid email address. This is actually pretty easy to do. From inside a controller, it looks like this:
use Symfony\Component\Validator\Constraints\Email;
// ...
public function addEmailAction($email)
{
$emailConstraint = new Email();
// all constraint "options" can be set this way
$emailConstraint->message = 'Invalid email address';
// use the validator to validate the value
$errorList = $this->get('validator')->validateValue(
$email,
$emailConstraint
);
if (count($errorList) == 0) {
// this IS a valid email address, do something
} else {
// this is *not* a valid email address
$errorMessage = $errorList[0]->getMessage();
// ... do something with the error
}
// ...
}
By calling validateValue on the validator, you can pass in a raw value and
the constraint object that you want to validate that value against. A full
list of the available constraints - as well as the full class name for each
constraint - is available in the :doc:`constraints reference </reference/constraints>`
section .
The validateValue method returns a :class:`Symfony\\Component\\Validator\\ConstraintViolationList`
object, which acts just like an array of errors. Each error in the collection
is a :class:`Symfony\\Component\\Validator\\ConstraintViolation` object,
which holds the error message on its getMessage method.
The Symfony2 validator is a powerful tool that can be leveraged to
guarantee that the data of any object is "valid". The power behind validation
lies in "constraints", which are rules that you can apply to properties or
getter methods of your object. And while you'll most commonly use the validation
framework indirectly when using forms, remember that it can be used anywhere
to validate any object.