Merge branch '6.0' into 6.1

* 6.0:
  Recommend a better charset for MySQL
  Update create_form_type_extension.rst
  Update uid.rst

Author: javiereguiluz

components/uid.rst

@@ -149,7 +149,6 @@ entity primary keys::
     namespace App\Entity;
 
     use Doctrine\ORM\Mapping as ORM;
-    use Symfony\Bridge\Doctrine\IdGenerator\UuidGenerator;
     use Symfony\Component\Uid\Uuid;
 
     class User implements UserInterface
@@ -158,7 +157,7 @@ entity primary keys::
          * @ORM\Id
          * @ORM\Column(type="uuid", unique=true)
          * @ORM\GeneratedValue(strategy="CUSTOM")
-         * @ORM\CustomIdGenerator(class=UuidGenerator::class)
+         * @ORM\CustomIdGenerator(class="doctrine.uuid_generator")
          */
         private $id;
 
@@ -308,7 +307,6 @@ entity primary keys::
     namespace App\Entity;
 
     use Doctrine\ORM\Mapping as ORM;
-    use Symfony\Bridge\Doctrine\IdGenerator\UlidGenerator;
     use Symfony\Component\Uid\Ulid;
 
     class Product
@@ -317,7 +315,7 @@ entity primary keys::
          * @ORM\Id
          * @ORM\Column(type="ulid", unique=true)
          * @ORM\GeneratedValue(strategy="CUSTOM")
-         * @ORM\CustomIdGenerator(class=UlidGenerator::class)
+         * @ORM\CustomIdGenerator(class="doctrine.ulid_generator")
          */
         private $id;
 

form/create_form_type_extension.rst

@@ -192,7 +192,7 @@ Specifically, you need to override the ``file_widget`` block:
 
     {% block file_widget %}
         {{ block('form_widget') }}
-        {% if image_url is not null %}
+        {% if image_url is defined and image_url is not null %}
             <img src="{{ asset(image_url) }}"/>
         {% endif %}
     {% endblock %}

reference/configuration/doctrine.rst

@@ -62,7 +62,7 @@ The following block shows all possible configuration keys:
                 unix_socket:          /tmp/mysql.sock
                 # the DBAL wrapperClass option
                 wrapper_class:        App\DBAL\MyConnectionWrapper
-                charset:              UTF8
+                charset:              utf8mb4
                 logging:              '%kernel.debug%'
                 platform_service:     App\DBAL\MyDatabasePlatformService
                 server_version:       '5.7'
@@ -96,7 +96,7 @@ The following block shows all possible configuration keys:
                     memory="true"
                     unix-socket="/tmp/mysql.sock"
                     wrapper-class="App\DBAL\MyConnectionWrapper"
-                    charset="UTF8"
+                    charset="utf8mb4"
                     logging="%kernel.debug%"
                     platform-service="App\DBAL\MyDatabasePlatformService"
                     server-version="5.7">