minor #2446 Fixed a FormTypeExtensionInterface deprecation (javieregu…

…iluz)

This PR was squashed before being merged into the 1.x branch (closes #2446).

Discussion
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Fixed a FormTypeExtensionInterface deprecation

This fixes #2445 thanks to the proposal made by @yceruto and reviewed by @xabbuh. Thanks!

Commits
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cde62cd Fixed a FormTypeExtensionInterface deprecation

src/Form/Extension/EasyAdminExtension.php

@@ -95,6 +95,15 @@ public function getExtendedType()
     {
         return LegacyFormHelper::getType('form');
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getExtendedTypes()
+    {
+        // needed to avoid a deprecation when using Symfony 4.2
+        return array(LegacyFormHelper::getType('form'));
+    }
 }
 
 class_alias('EasyCorp\Bundle\EasyAdminBundle\Form\Extension\EasyAdminExtension', 'JavierEguiluz\Bundle\EasyAdminBundle\Form\Extension\EasyAdminExtension', false);