Merge branch '2.3' into 2.5

* 2.3: (33 commits)
  Fixing bad reference
  [#4743] parts -> part - subjective, but this sounds slightly better to me
  Update web_server_configuration.rst
  Update web_server_configuration.rst
  Update web_server_configuration.rst
  Add exception to console exception log
  [#4454] Re-wording section, but it may not actually be accurate
  More concrete explanation of validation groups
  Adding missing index/map documents
  [#4611] A few more tweaks and fixes
  Basically copying a section about upgrading other libraries down into the minor version section
  [#4611] Removing a few entries I meant to remove before
  [#4611] Making many tweaks thanks to guys like Javier, Wouter, Christian (xabbuh) and Stof
  Adding a guide about upgrading
  Fix typo and remove redundant sentence
  [Reference] Add default_locale config description
  Clarify tip for creating a new AppBundle
  Update forms.rst
  Rewroded some contents and fixed some lists of elements
  MAde some tweaks suggested by Wouter
  ...

Conflicts:
	book/http_cache.rst

best_practices/creating-the-project.rst

@@ -152,8 +152,7 @@ that follows these best practices:
 
 .. tip::
 
-    If you are using Symfony 2.6 or a newer version, the ``AppBundle`` bundle
-    is already generated for you. If you are using an older Symfony version,
+    If your Symfony installation doesn't come with a pre-generated ``AppBundle``,
     you can generate it by hand executing this command:
 
     .. code-block:: bash

best_practices/forms.rst

@@ -13,8 +13,8 @@ Building Forms
     Define your forms as PHP classes.
 
 The Form component allows you to build forms right inside your controller
-code. Honestly, unless you need to reuse the form somewhere else, that's
-totally fine. But for organization and reuse, we recommend that you define each
+code. This is perfectly fine if you don't need to reuse the form somewhere else.
+But for organization and reuse, we recommend that you define each
 form in its own PHP class::
 
     namespace AppBundle\Form;

best_practices/templates.rst

@@ -153,6 +153,7 @@ name is irrelevant because you never use it in your own code):
         app.twig.app_extension:
             class:     AppBundle\Twig\AppExtension
             arguments: ["@markdown"]
+            public: false
             tags:
                 - { name: twig.extension }
 

book/forms.rst

@@ -526,6 +526,7 @@ to an array callback::
 
     use Symfony\Component\OptionsResolver\OptionsResolverInterface;
 
+    // ...
     public function setDefaultOptions(OptionsResolverInterface $resolver)
     {
         $resolver->setDefaults(array(
@@ -541,23 +542,51 @@ This will call the static method ``determineValidationGroups()`` on the
 The Form object is passed as an argument to that method (see next example).
 You can also define whole logic inline by using a ``Closure``::
 
+    use Acme\AcmeBundle\Entity\Client;
     use Symfony\Component\Form\FormInterface;
     use Symfony\Component\OptionsResolver\OptionsResolverInterface;
 
+    // ...
     public function setDefaultOptions(OptionsResolverInterface $resolver)
     {
         $resolver->setDefaults(array(
             'validation_groups' => function(FormInterface $form) {
                 $data = $form->getData();
-                if (Entity\Client::TYPE_PERSON == $data->getType()) {
+                if (Client::TYPE_PERSON == $data->getType()) {
                     return array('person');
-                } else {
-                    return array('company');
                 }
+
+                return array('company');
+            },
+        ));
+    }
+
+Using the ``validation_groups`` option overrides the default validation
+group which is being used. If you want to validate the default constraints
+of the entity as well you have to adjust the option as follows::
+
+    use Acme\AcmeBundle\Entity\Client;
+    use Symfony\Component\Form\FormInterface;
+    use Symfony\Component\OptionsResolver\OptionsResolverInterface;
+
+    // ...
+    public function setDefaultOptions(OptionsResolverInterface $resolver)
+    {
+        $resolver->setDefaults(array(
+            'validation_groups' => function(FormInterface $form) {
+                $data = $form->getData();
+                if (Client::TYPE_PERSON == $data->getType()) {
+                    return array('Default', 'person');
+                }
+
+                return array('Default', 'company');
             },
         ));
     }
 
+You can find more information about how the validation groups and the default constraints
+work in the book section about :ref:`validation groups <book-validation-validation-groups>`.
+
 .. index::
    single: Forms; Validation groups based on clicked button
 

book/http_cache.rst

@@ -333,7 +333,14 @@ its creation more manageable::
     // set a custom Cache-Control directive
     $response->headers->addCacheControlDirective('must-revalidate', true);
 
-Public vs private Responses
+.. tip::
+
+    If you need to set cache headers for many different controller actions,
+    you might want to look into the FOSHttpCacheBundle_. It provides a way
+    to define cache headers based on the URL pattern and other request
+    properties.
+
+Public vs Private Responses
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 Both gateway and proxy caches are considered "shared" caches as the cached
@@ -399,9 +406,10 @@ header when none is set by the developer by following these rules:
   ``private`` directive automatically (except when ``s-maxage`` is set).
 
 .. _http-expiration-validation:
+.. _http-expiration-and-validation:
 
-HTTP Expiration and Validation
-------------------------------
+HTTP Expiration, Validation and Invalidation
+--------------------------------------------
 
 The HTTP specification defines two caching models:
 
@@ -418,7 +426,9 @@ The HTTP specification defines two caching models:
   header) to check if the page has changed since being cached.
 
 The goal of both models is to never generate the same response twice by relying
-on a cache to store and return "fresh" responses.
+on a cache to store and return "fresh" responses. To achieve long caching times
+but still provide updated content immediately, *cache invalidation* is
+sometimes used.
 
 .. sidebar:: Reading the HTTP Specification
 
@@ -772,7 +782,7 @@ at some interval (the expiration) to verify that the content is still valid.
     annotations. See the `FrameworkExtraBundle documentation`_.
 
 .. index::
-    pair: Cache; Configuration
+   pair: Cache; Configuration
 
 More Response Methods
 ~~~~~~~~~~~~~~~~~~~~~
@@ -800,8 +810,110 @@ Additionally, most cache-related HTTP headers can be set via the single
     ));
 
 .. index::
-  single: Cache; ESI
-  single: ESI
+   single: Cache; Invalidation
+
+.. _http-cache-invalidation:
+
+Cache Invalidation
+~~~~~~~~~~~~~~~~~~
+
+    "There are only two hard things in Computer Science: cache invalidation
+    and naming things." -- Phil Karlton
+
+Once an URL is cached by a gateway cache, the cache will not ask the
+application for that content anymore. This allows the cache to provide fast
+responses and reduces the load on your application. However, you risk
+delivering outdated content. A way out of this dilemma is to use long
+cache lifetimes, but to actively notify the gateway cache when content
+changes. Reverse proxies usually provide a channel to receive such
+notifications, typically through special HTTP requests.
+
+.. caution::
+
+    While cache invalidation is powerful, avoid it when possible. If you fail
+    to invalidate something, outdated caches will be served for a potentially
+    long time. Instead, use short cache lifetimes or use the validation model,
+    and adjust your controllers to perform efficient validation checks as
+    explained in :ref:`optimizing-cache-validation`.
+
+    Furthermore, since invalidation is a topic specific to each type of reverse
+    proxy, using this concept will tie you to a specific reverse proxy or need
+    additional efforts to support different proxies.
+
+Sometimes, however, you need that extra performance you can get when
+explicitly invalidating. For invalidation, your application needs to detect
+when content changes and tell the cache to remove the URLs which contain
+that data from its cache.
+
+.. tip::
+
+    If you want to use cache invalidation, have a look at the
+    `FOSHttpCacheBundle`_. This bundle provides services to help with various
+    cache invalidation concepts, and also documents the configuration for the
+    a couple of common caching proxies.
+
+If one content corresponds to one URL, the ``PURGE`` model works well.
+You send a request to the cache proxy with the HTTP method ``PURGE`` (using
+the word "PURGE" is a convention, technically this can be any string) instead
+of ``GET`` and make the cache proxy detect this and remove the data from the
+cache instead of going to Symfony to get a response.
+
+Here is how you can configure the Symfony reverse proxy to support the
+``PURGE`` HTTP method::
+
+    // app/AppCache.php
+
+    // ...
+    use Symfony\Bundle\FrameworkBundle\HttpCache\HttpCache;
+    use Symfony\Component\HttpFoundation\Request;
+    use Symfony\Component\HttpFoundation\Response;
+
+    class AppCache extends HttpCache
+    {
+        protected function invalidate(Request $request, $catch = false)
+        {
+            if ('PURGE' !== $request->getMethod()) {
+                return parent::invalidate($request, $catch);
+            }
+
+            if ('127.0.0.1' !== $request->getClientIp()) {
+                return new Response('Invalid HTTP method', Response::HTTP_BAD_REQUEST);
+            }
+
+            $response = new Response();
+            if ($this->getStore()->purge($request->getUri())) {
+                $response->setStatusCode(200, 'Purged');
+            } else {
+                $response->setStatusCode(200, 'Not found');
+            }
+
+            return $response;
+        }
+    }
+
+.. caution::
+
+    You must protect the ``PURGE`` HTTP method somehow to avoid random people
+    purging your cached data.
+
+**Purge** instructs the cache to drop a resource in *all its variants*
+(according to the ``Vary`` header, see above). An alternative to purging is
+**refreshing** a content. Refreshing means that the caching proxy is
+instructed to discard its local cache and fetch the content again. This way,
+the new content is already available in the cache. The drawback of refreshing
+is that variants are not invalidated.
+
+In many applications, the same content bit is used on various pages with
+different URLs. More flexible concepts exist for those cases:
+
+* **Banning** invalidates responses matching regular expressions on the
+  URL or other criteria;
+* **Cache tagging** lets you add a tag for each content used in a response
+  so that you can invalidate all URLs containing a certain content.
+
+.. index::
+   single: Cache; ESI
+   single: ESI
 
 .. _edge-side-includes:
 
@@ -1048,70 +1160,6 @@ The ``render_esi`` helper supports two other useful options:
     of ``continue`` indicating that, in the event of a failure, the gateway cache
     will simply remove the ESI tag silently.
 
-.. index::
-    single: Cache; Invalidation
-
-.. _http-cache-invalidation:
-
-Cache Invalidation
-------------------
-
-    "There are only two hard things in Computer Science: cache invalidation
-    and naming things." -- Phil Karlton
-
-You should never need to invalidate cached data because invalidation is already
-taken into account natively in the HTTP cache models. If you use validation,
-you never need to invalidate anything by definition; and if you use expiration
-and need to invalidate a resource, it means that you set the expires date
-too far away in the future.
-
-.. note::
-
-    Since invalidation is a topic specific to each type of reverse proxy,
-    if you don't worry about invalidation, you can switch between reverse
-    proxies without changing anything in your application code.
-
-Actually, all reverse proxies provide ways to purge cached data, but you
-should avoid them as much as possible. The most standard way is to purge the
-cache for a given URL by requesting it with the special ``PURGE`` HTTP method.
-
-Here is how you can configure the Symfony reverse proxy to support the
-``PURGE`` HTTP method::
-
-    // app/AppCache.php
-
-    // ...
-    use Symfony\Bundle\FrameworkBundle\HttpCache\HttpCache;
-    use Symfony\Component\HttpFoundation\Request;
-    use Symfony\Component\HttpFoundation\Response;
-
-    class AppCache extends HttpCache
-    {
-        protected function invalidate(Request $request, $catch = false)
-        {
-            if ('PURGE' !== $request->getMethod()) {
-                return parent::invalidate($request, $catch);
-            }
-
-            $response = new Response();
-            if ($this->getStore()->purge($request->getUri())) {
-                $response->setStatusCode(Response::HTTP_OK, 'Purged');
-            } else {
-                $response->setStatusCode(Response::HTTP_NOT_FOUND, 'Not purged');
-            }
-
-            return $response;
-        }
-    }
-
-.. versionadded:: 2.4
-    Support for HTTP status code constants was introduced in Symfony 2.4.
-
-.. caution::
-
-    You must protect the ``PURGE`` HTTP method somehow to avoid random people
-    purging your cached data.
-
 Summary
 -------
 
@@ -1139,3 +1187,4 @@ Learn more from the Cookbook
 .. _`P6 - Caching: Browser and intermediary caches`: http://tools.ietf.org/html/draft-ietf-httpbis-p6-cache
 .. _`FrameworkExtraBundle documentation`: http://symfony.com/doc/current/bundles/SensioFrameworkExtraBundle/annotations/cache.html
 .. _`ESI`: http://www.w3.org/TR/esi-lang
+.. _`FOSHttpCacheBundle`: http://foshttpcachebundle.readthedocs.org/

book/security.rst

@@ -1141,8 +1141,7 @@ Next, you'll need to create a route for this URL (but not a controller):
         return $collection;
 
 And that's it! By sending a user to ``/logout`` (or whatever you configure
-the ``path`` to be), Symfony will un-authenticate the current user. and 
-redirect them the homepage (the value defined by ``target``).
+the ``path`` to be), Symfony will un-authenticate the current user.
 
 Once the user has been logged out, they will be redirected to whatever path
 is defined by the ``target`` parameter above (e.g. the ``homepage``).

book/validation.rst

@@ -817,11 +817,39 @@ With this configuration, there are three validation groups:
     that belong to no other group.
 
 ``User``
-    Equivalent to all constraints of the ``User`` object in the ``Default`` group.
+    Equivalent to all constraints of the ``User`` object in the ``Default``
+    group. This is always the name of the class. The difference between this
+    and ``Default`` is explained below.
 
 ``registration``
     Contains the constraints on the ``email`` and ``password`` fields only.
 
+Constraints in the ``Default`` group of a class are the constraints that have either no
+explicit group configured or that are configured to a group equal to the class name or
+the string ``Default``.
+
+.. caution::
+
+    When validating *just* the User object, there is no difference between the ``Default`` group
+    and the ``User`` group. But, there is a difference if ``User`` has embedded objects. For example,
+    imagine ``User`` has an ``address`` property that contains some ``Address`` object and that
+    you've added the :doc:`/reference/constraints/Valid` constraint to this property so that it's
+    validated when you validate the ``User`` object.
+
+    If you validate ``User`` using the ``Default`` group, then any constraints on the ``Address``
+    class that are in the ``Default`` group *will* be used. But, if you validate ``User`` using the
+    ``User`` validation group, then only constraints on the ``Address`` class with the ``User``
+    group will be validated.
+
+    In other words, the ``Default`` group and the class name group (e.g. ``User``) are identical,
+    except when the class is embedded in another object that's actually the one being validated.
+
+    If you have inheritance (e.g. ``User extends BaseUser``) and you validate
+    with the class name of the subclass (i.e. ``User``), then all constraints
+    in the ``User`` and ``BaseUser`` will be validated. However, if you validate
+    using the base class (i.e. ``BaseUser``), then only the constraints in
+    the ``BaseUser`` group will be validated.
+
 To tell the validator to use a specific group, pass one or more group names
 as the third argument to the ``validate()`` method::