Merge branch '6.4' into 7.0

* 6.4:
  [Value Resolver] Added `RequestPayloadValueResolver` section

Author: javiereguiluz

controller.rst

@@ -379,6 +379,8 @@ attribute, arguments of your controller's action can be automatically fulfilled:
         // ...
     }
 
+.. _controller-mapping-query-string:
+
 Mapping The Whole Query String
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -440,6 +442,8 @@ HTTP status to return if the validation fails::
 
 The default status code returned if the validation fails is 404.
 
+.. _controller-mapping-request-payload:
+
 Mapping Request Payload
 ~~~~~~~~~~~~~~~~~~~~~~~
 

controller/value_resolver.rst

@@ -75,6 +75,14 @@ Symfony ships with the following value resolvers in the
     The example above allows requesting only ``/cards/D`` and ``/cards/S``
     URLs and leads to 404 Not Found response in two other cases.
 
+:class:`Symfony\\Component\\HttpKernel\\Controller\\ArgumentResolver\\RequestPayloadValueResolver`
+    Maps the request payload or the query string into the type-hinted object.
+
+    Because this is a :ref:`targeted value resolver <value-resolver-targeted>`,
+    you'll have to use either the :ref:`MapRequestPayload <controller-mapping-request-payload>`
+    or the :ref:`MapQueryString <controller-mapping-query-string>` attribute
+    in order to use this resolver.
+
 :class:`Symfony\\Component\\HttpKernel\\Controller\\ArgumentResolver\\RequestAttributeValueResolver`
     Attempts to find a request attribute that matches the name of the argument.
 
@@ -393,6 +401,8 @@ command to see which argument resolvers are present and in which order they run:
 You can also configure the name passed to the ``ValueResolver`` attribute to target
 your resolver. Otherwise it will default to the service's id.
 
+.. _value-resolver-targeted:
+
 ``controller.targeted_value_resolver``
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~