Merge branch '2.7' into 2.8

* 2.7:
  Update custom_constraint.rst
  Add form_theme in error customization
  Wrap the instantiation in parenthesis, and chain away

Author: xabbuh

email.rst

@@ -103,7 +103,7 @@ an email is pretty straightforward::
 
     public function indexAction($name)
     {
-        $message = new \Swift_Message('Hello Email')
+        $message = (new \Swift_Message('Hello Email'))
             ->setFrom('send@example.com')
             ->setTo('recipient@example.com')
             ->setBody(
@@ -125,6 +125,7 @@ an email is pretty straightforward::
             )
             */
         ;
+
         $this->get('mailer')->send($message);
 
         return $this->render(...);

email/dev_environment.rst

@@ -100,7 +100,7 @@ Now, suppose you're sending an email to ``recipient@example.com``.
 
     public function indexAction($name)
     {
-        $message = new \Swift_Message('Hello Email')
+        $message = (new \Swift_Message('Hello Email'))
             ->setFrom('send@example.com')
             ->setTo('recipient@example.com')
             ->setBody(
@@ -110,6 +110,7 @@ Now, suppose you're sending an email to ``recipient@example.com``.
                 )
             )
         ;
+
         $this->get('mailer')->send($message);
 
         return $this->render(...);

email/testing.rst

@@ -14,7 +14,7 @@ Start with an easy controller action that sends an email::
 
     public function sendEmailAction($name)
     {
-        $message = new \Swift_Message('Hello Email')
+        $message = (new \Swift_Message('Hello Email'))
             ->setFrom('send@example.com')
             ->setTo('recipient@example.com')
             ->setBody('You should see me from the profiler!')

form/form_customization.rst

@@ -873,6 +873,8 @@ and customize the ``form_errors`` fragment.
 
     .. code-block:: html+twig
 
+        {% form_theme form _self %}
+
         {# form_errors.html.twig #}
         {% block form_errors %}
             {% spaceless %}
@@ -933,6 +935,8 @@ fields (e.g. a whole form), and not just an individual field.
 
     .. code-block:: html+twig
 
+        {% form_theme form _self %}
+
         {# form_errors.html.twig #}
         {% block form_errors %}
             {% spaceless %}

validation/custom_constraint.rst

@@ -45,7 +45,7 @@ includes some simple default logic::
     // in the base Symfony\Component\Validator\Constraint class
     public function validatedBy()
     {
-        return get_class($this).'Validator';
+        return ContainsAlphanumericValidator::class;
     }
 
 In other words, if you create a custom ``Constraint`` (e.g. ``MyConstraint``),