Added component Validator section

components/index.rst

@@ -28,6 +28,7 @@ The Components
     stopwatch
     templating/index
     translation/index
+    validator/index
     yaml/index
 
 .. include:: /components/map.rst.inc

components/map.rst.inc

@@ -135,6 +135,11 @@
   * :doc:`/components/translation/usage`
   * :doc:`/components/translation/custom_formats`
 
+* :doc:`/components/validator/index`
+
+  * :doc:`/components/validator/introduction`
+  * :doc:`/components/validator/resources`
+
 * :doc:`/components/yaml/index`
 
   * :doc:`/components/yaml/introduction`

components/validator/builtin_validators.rst

@@ -0,0 +1,8 @@
+.. index::
+    single: Validator; Built In Validators
+
+Built In Validators
+===================
+
+For each validation rule, the component ships a Constraint class and its associated Validator class.
+The Constraint object describes the rule to check and the Validator implementation runs the validation logic.

components/validator/custom_validation.rst

@@ -0,0 +1,5 @@
+.. index::
+    single: Validator; Custom Validation
+
+Custom Validation
+=================

components/validator/index.rst

@@ -0,0 +1,13 @@
+Validator
+=========
+
+.. toctree::
+    :maxdepth: 2
+
+    introduction
+    resources
+    metadata
+    builtin_validators
+    validation_groups
+    custom_validation
+    internationalization

components/validator/internationalization.rst

@@ -0,0 +1,5 @@
+.. index::
+    single: Validator; Internationalization
+
+Internationalization
+====================

components/validator/introduction.rst

@@ -0,0 +1,84 @@
+.. index::
+   single: Validator
+   single: Components; Validator
+
+The Validator Component
+=======================
+
+    The Validator component provides tools to validate values following the
+    `JSR-303 Bean Validation specification`_. With the component, this is done in two parts:
+    * ``Contraints``: a constraint describes a rule that need to be validated
+    * ``Validators``: a list of classes that implement the validation logic for common usages
+
+Installation
+------------
+
+You can install the component in 2 different ways:
+
+* :doc:`Install it via Composer </components/using_components>` (``symfony/validator`` on `Packagist`_);
+* Use the official Git repository (https://github.com/symfony/Validator).
+
+.. include:: /components/require_autoload.rst.inc
+
+Usage
+-----
+
+The Validator component allows you to use very advanced validation rules, but
+it is also really easy to do easy validation tasks. For instance, if you want
+to validate that a string is at least 10 character long, the only code you need is::
+
+    use Symfony\Component\Validator\Validation;
+    use Symfony\Component\Validator\Constraints\Length;
+
+    $validator = Validation::createValidator();
+
+    $violations = $validator->validateValue('Bernhard', new Length(array('min' => 10)));
+
+    if (0 !== count($violations)) {
+        // there are errors, now you can show them
+        foreach ($violations as $violation) {
+            echo $violation->getMessage().'<br>';
+        }
+    }
+
+Retrieving a Validator Instance
+-------------------------------
+
+The :class:`Symfony\\Component\\Validator\\Validator` class is the main access
+point of the Validator component. To create a new instance of this class, it
+is recommended to use the :class:`Symfony\\Component\\Validator\\Validation`
+class.
+
+You can get a very basic ``Validator`` by calling
+:method:`Validation::createValidator() <Symfony\\Component\\Validator\\Validation::createValidator>`::
+
+    use Symfony\Component\Validator\Validation;
+
+    $validator = Validation::createValidator();
+
+The created validator can be used to validate strings, arrays, numbers, but it
+can't validate classes. In order to achieve that, you have to configure the ``Validator``
+class. To do that, you can use the :class:`Symfony\\Component\\Validator\\ValidatorBuilder`.
+This class can be retrieved by using the
+:method:`Validation::createValidatorBuilder() <Symfony\\Component\\Validator\\Validation::createValidatorBuilder>`
+method::
+
+    use Symfony\Component\Validator\Validation;
+
+    $validator = Validation::createValidatorBuilder()
+        // ... build a custom instance of the Validator
+        ->getValidator();
+
+In the next sections, you'll learn about all things you can configure in the Validator.
+
+Sections
+--------
+
+* :doc:`/components/validator/resources`
+* :doc:`/components/validator/builtin_validators`
+* :doc:`/components/validator/validation_groups`
+* :doc:`/components/validator/internationalization`
+* :doc:`/components/validator/custom_validation`
+
+.. _`JSR-303 Bean Validation specification`: http://jcp.org/en/jsr/detail?id=303
+.. _Packagist: https://packagist.org/packages/symfony/validator

components/validator/metadata.rst

@@ -0,0 +1,84 @@
+.. index::
+    single: Validator; Metadata
+
+Metadata
+========
+
+The :class:`Symfony\\Component\\Validator\\Mapping\\ClassMetadata` class represents and manages all the configured constraints on a given class.
+
+Properties
+----------
+
+Validating class properties is the most basic validation technique. Validation component
+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::
+
+    // ...
+    use Symfony\Component\Validator\Mapping\ClassMetadata;
+    use Symfony\Component\Validator\Constraints as Assert;
+
+    class Author
+    {
+        private $firstName;
+
+        public static function loadValidatorMetadata(ClassMetadata $metadata)
+        {
+            $metadata->addPropertyConstraint('firstName', new Assert\NotBlank());
+            $metadata->addPropertyConstraint(
+                'firstName',
+                new Assert\Length(array("min" => 3))
+            );
+        }
+    }
+
+Getters
+-------
+
+Constraints can also be applied to the return value of a method. Symfony
+allows you to add a constraint to any public method whose name starts with
+"get" or "is". In this guide, both of these types of methods are referred
+to as "getters".
+
+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``::
+
+    // ...
+    use Symfony\Component\Validator\Mapping\ClassMetadata;
+    use Symfony\Component\Validator\Constraints as Assert;
+
+    class Author
+    {
+        public static function loadValidatorMetadata(ClassMetadata $metadata)
+        {
+            $metadata->addGetterConstraint('passwordLegal', new Assert\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" or "is") 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.
+
+Classes
+-------
+
+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.