@@ -687,23 +687,19 @@ the ``notice`` message:
 
 .. code-block:: html+jinja
 
-{% if app.session.started %}
-{% for flashMessage in app.session.flashbag.get('notice') %}
-<div class="flash-notice">
-{{ flashMessage }}
-</div>
-{% endfor %}
-{% endif %}
+{% for flashMessage in app.session.flashbag.get('notice') %}
+<div class="flash-notice">
+{{ flashMessage }}
+</div>
+{% endfor %}
 
 .. code-block:: html+php
 
-<?php if ($view['session']->isStarted()): ?>
-<?php foreach ($view['session']->getFlashBag()->get('notice') as $message): ?>
-<div class="flash-notice">
-<?php echo "<div class='flash-error'>$message</div>" ?>
-</div>
-<?php endforeach; ?>
-<?php endif; ?>
+<?php foreach ($view['session']->getFlashBag()->get('notice') as $message): ?>
+<div class="flash-notice">
+<?php echo "<div class='flash-error'>$message</div>" ?>
+</div>
+<?php endforeach; ?>
 
 By design, flash messages are meant to live for exactly one request (they're
 "gone in a flash"). They're designed to be used across redirects exactly as

@@ -1462,7 +1462,7 @@ and ``nullable``. Take a few examples:
 <!--
 A string field length 255 that cannot be null
 (reflecting the default values for the "length" and *nullable* options)
-type attribute is necessary in yaml definitions
+type attribute is necessary in xml definitions
 -->
 <field name="name" type="string" />
 <field name="email"

@@ -975,7 +975,7 @@ possible.
 
 .. tip::
 
-The listener listener only responds to local IP addresses or trusted
+The listener only responds to local IP addresses or trusted
 proxies.
 
 .. note::

@@ -1381,43 +1381,9 @@ in a JavaScript string, use the ``js`` context:
 Debugging
 ---------
 
-.. versionadded:: 2.0.9
-This feature is available as of Twig ``1.5.x``, which was first shipped
-with Symfony 2.0.9.
-
 When using PHP, you can use ``var_dump()`` if you need to quickly find the
 value of a variable passed. This is useful, for example, inside your controller.
-The same can be achieved when using Twig by using the debug extension. This
-needs to be enabled in the config:
-
-.. configuration-block::
-
-.. code-block:: yaml
-
-# app/config/config.yml
-services:
-acme_hello.twig.extension.debug:
-class: Twig_Extension_Debug
-tags:
-- { name: 'twig.extension' }
-
- .. code-block:: xml
-
-<!-- app/config/config.xml -->
-<services>
-<service id="acme_hello.twig.extension.debug" class="Twig_Extension_Debug">
-<tag name="twig.extension" />
-</service>
-</services>
-
- .. code-block:: php
-
-// app/config/config.php
-use Symfony\Component\DependencyInjection\Definition;
-
-$definition = new Definition('Twig_Extension_Debug');
-$definition->addTag('twig.extension');
-$container->setDefinition('acme_hello.twig.extension.debug', $definition);
+The same can be achieved when using Twig thanks to the the debug extension.
 
 Template parameters can then be dumped using the ``dump`` function:
 

@@ -779,6 +779,9 @@ With this configuration, there are two validation groups:
 
 * ``Default`` - contains the constraints not assigned to any other group;
 
+* ``User`` - contains the constraints that belongs to group ``Default``
+(this group is useful for :ref:`book-validation-group-sequence`);
+
 * ``registration`` - contains the constraints on the ``email`` and ``password``
 fields only.
 
@@ -787,13 +790,138 @@ 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
 
+.. _book-validation-group-sequence:
+
+Group Sequence
+--------------
+
+In some cases, you want to validate your groups by steps. To do this, you can
+use the ``GroupSequence`` feature. In the case, an object defines a group sequence,
+and then the groups in the group sequence are validated in order.
+
+.. tip::
+
+Group sequences cannot contain the group ``Default``, as this would create
+a loop. Instead, use the group ``{ClassName}`` (e.g. ``User``) instead.
+
+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({"Strict", "User"})
+*/
+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 -->
+<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>
+
+ .. 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.
+
 .. _book-validation-raw-values:
 
 Validating Values and Arrays

@@ -443,7 +443,7 @@ and sometimes only:
 
 By default ``connection`` would be an array in the first case and a string
 in the second making it difficult to validate. You can ensure it is always
-an array with with ``fixXmlConfig``.
+an array with ``fixXmlConfig``.
 
 You can further control the normalization process if you need to. For example,
 you may want to allow a string to be set and used as a particular key or several

@@ -56,7 +56,7 @@ Adding Subscriber Services
 ``EventSubscribers`` can be added using the
 :method:`Symfony\\Component\\EventDiser\\ContainerAwareEventDiser::addSubscriberService`
 method where the first argument is the service ID of the subscriber service,
-and the second argument is the the service's class name (which must implement
+and the second argument is the service's class name (which must implement
 :class:`Symfony\\Component\\EventDiser\\EventSubscriberInterface`) as follows::
 
 $diser->addSubscriberService(

@@ -79,7 +79,7 @@ examples if you wish to write your own.
 Example usage::
 
 use Symfony\Component\HttpFoundation\Session\Session;
-use Symfony\Component\HttpFoundation\Session\Storage\SessionStorage;
+use Symfony\Component\HttpFoundation\Session\Storage\NativeSessionStorage;
 use Symfony\Component\HttpFoundation\Session\Storage\Handler\PdoSessionHandler;
 
 $storage = new NativeSessionStorage(array(), new PdoSessionHandler());

@@ -329,16 +329,3 @@ Compact method to process display all flashes at once::
 echo "<div class='flash-$type'>$message</div>\n";
 }
 }
-
-.. caution::
-
-As flash messages use a session to store the messages from one request to
-the next one, a session will be automatically started when you read the
-flash messages even if none already exists. To avoid that default
-behavior, test if there is an existing session first::
-
-if ($session->isStarted()) {
-foreach ($session->getFlashBag()->get('warning', array()) as $message) {
-echo "<div class='flash-warning'>$message</div>";
-}
-}

@@ -34,15 +34,15 @@ Set up your user information with your real name and a working email address:
 
 .. tip::
 
-If your IDE creates configuration files inside project's directory,
+If your IDE creates configuration files inside the project's directory,
 you can use global ``.gitignore`` file (for all projects) or
 ``.git/info/exclude`` file (per project) to ignore them. See
 `'s documentation`_.
 
 .. tip::
 
 Windows users: when installing Git, the installer will ask what to do with
-line endings and suggests to replace all Lf by CRLF. This is the wrong
+line endings, and suggests replacing all LF with CRLF. This is the wrong
 setting if you wish to contribute to Symfony! Selecting the as-is method is
 your best choice, as git will convert your line feeds to the ones in the
 repository. If you have already installed Git, you can check the value of
@@ -52,8 +52,8 @@ Set up your user information with your real name and a working email address:
 
 $ git config core.autocrlf
 
- This will return either "false", "input" or "true", "true" and "false" being
-the wrong values. Set it to another value by typing:
+ This will return either "false", "input" or "true"; "true" and "false" being
+the wrong values. Change it to "input" by typing:
 
 .. code-block:: bash
 
@@ -344,7 +344,7 @@ because you want early feedback on your work, add an item to todo-list:
 .. code-block:: text
 
 - [ ] finish the code
-- [ ] gather feedback my changes
+- [ ] gather feedback for my changes
 
 As long as you have items in the todo-list, please prefix the pull request
 title with "[WIP]".

@@ -49,11 +49,11 @@ example containing most features described below:
 
 /**
 * @param string $dummy Some argument description
-* @param array $options
+* @param array $options
 *
 * @return string|null Transformed input
 */
-private function transformText($dummy, $options = array())
+private function transformText($dummy, array $options = array())
 {
 $mergedOptions = array_merge(
 $options,