Add Upgrade entry

yceruto · yceruto · commit 3cda2ef8c809 · 2018-04-08T12:21:08.000-04:00
diff --git a/UPGRADE-4.2.md b/UPGRADE-4.2.md
@@ -0,0 +1,34 @@
+UPGRADE FROM 4.1 to 4.2
+=======================
+
+Form
+----
+
+ * Deprecated `ChoiceLoaderInterface` implementation in `CountryType`, `LanguageType`, `LocaleType` and `CurrencyType`. Use the "choice_loader" option instead.
+
+   Before:
+   ```php
+   class MyCountryType extends CountryType
+   {
+       public function loadChoiceList()
+       {
+           // override the method
+       }
+   }
+   ```
+
+   After:
+   ```php
+   class MyCountryType extends AbstractType
+   {
+       public function getParent()
+       {
+           return CountryType::class;
+       }
+
+       public function configureOptions(OptionsResolver $resolver)
+       {
+           $resolver->setDefault('choice_loader', ...); // override the option instead
+       }
+   }
+   ```
