Rollback

Author: gary houbre

reference/forms/types/options/choice_loader.rst.inc

@@ -1,39 +1,75 @@
-choice_loader ~~~~~~~~~~~~~ **type**:
-:class:`Symfony\\Component\\Form\\ChoiceList\\Loader\\ChoiceLoaderInterface` The
-``choice_loader`` option can be used instead of the ``choices`` option. It
+choice_loader
+~~~~~~~~~~~~~
+
+**type**: :class:`Symfony\\Component\\Form\\ChoiceList\\Loader\\ChoiceLoaderInterface`
+
+The ``choice_loader`` option can be used instead of the ``choices`` option. It
 allows to create a list lazily or partially when fetching only the choices for a
 set of submitted values (i.e. querying a search engine like ``ElasticSearch``
-can be a heavy process). You can use an instance of
-:class:`Symfony\\Component\\Form\\ChoiceList\\Loader\\CallbackChoiceLoader` if
-you want to take advantage of lazy loading:: use App\StaticClass; use
-Symfony\Component\Form\ChoiceList\Loader\CallbackChoiceLoader; use
-Symfony\Component\Form\Extension\Core\Type\ChoiceType; // ...
-$builder->add('loaded_choices', ChoiceType::class, [ 'choice_loader' => new
-CallbackChoiceLoader(function() { return StaticClass::getConstants(); }), ]);
+can be a heavy process).
+
+You can use an instance of :class:`Symfony\\Component\\Form\\ChoiceList\\Loader\\CallbackChoiceLoader`
+if you want to take advantage of lazy loading::
+
+    use App\StaticClass;
+    use Symfony\Component\Form\ChoiceList\Loader\CallbackChoiceLoader;
+    use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
+    // ...
+
+    $builder->add('loaded_choices', ChoiceType::class, [
+        'choice_loader' => new CallbackChoiceLoader(function() {
+            return StaticClass::getConstants();
+        }),
+    ]);
+
 This will cause the call of ``StaticClass::getConstants()`` to not happen if the
 request is redirected and if there is no pre set or submitted data. Otherwise
-the choice options would need to be resolved thus triggering the callback. When
-you're defining a custom choice type that may be reused in many fields (like
-entries of a collection) or reused in multiple forms at once, you should use the
-:class:`Symfony\\Component\\Form\\ChoiceList\\ChoiceList` static methods to wrap
-the loader and make the choice list cacheable for better performance:: //
-src/Form/ConstantsType.php namespace App\Form; use
-App\Form\ChoiceList\CustomChoiceLoader; use App\StaticClass; use
-Symfony\Component\Form\AbstractType; use
-Symfony\Component\Form\ChoiceList\ChoiceList; use
-Symfony\Component\Form\Extension\Core\Type\ChoiceType; use
-Symfony\Component\OptionsResolver\Options; use
-Symfony\Component\OptionsResolver\OptionsResolver; class ConstantsType extends
-AbstractType { public static function getExtendedTypes(): iterable { return
-[ChoiceType::class]; } public function configureOptions(OptionsResolver
-$resolver) { $resolver->setDefaults([ // the example below will create a
-CallbackChoiceLoader from the callable 'choice_loader' =>
-ChoiceList::lazy($this, function() { return StaticClass::getConstants(); }), //
-you can pass your own loader as well, depending on other options 'some_key' =>
-null, 'choice_loader' => function (Options $options) { return
-ChoiceList::loader( // pass the instance of the type or type extension which is
-// currently configuring the choice list as first argument $this, // pass the
-other option to the loader new CustomChoiceLoader($options['some_key']), //
-ensure the type stores a loader per key // by using the special third argument
-"$vary" // an array containing anything that "changes" the loader
-[$options['some_key']] ); }, ]); } }
+the choice options would need to be resolved thus triggering the callback.
+
+When you're defining a custom choice type that may be reused in many fields
+(like entries of a collection) or reused in multiple forms at once, you
+should use the :class:`Symfony\\Component\\Form\\ChoiceList\\ChoiceList`
+static methods to wrap the loader and make the choice list cacheable for
+better performance::
+
+    use App\Form\ChoiceList\CustomChoiceLoader;
+    use App\StaticClass;
+    use Symfony\Component\Form\AbstractType;
+    use Symfony\Component\Form\ChoiceList\ChoiceList;
+    use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
+    use Symfony\Component\OptionsResolver\Options;
+    use Symfony\Component\OptionsResolver\OptionsResolver;
+
+    class ConstantsType extends AbstractType
+    {
+        public static function getExtendedTypes(): iterable
+        {
+            return [ChoiceType::class];
+        }
+
+        public function configureOptions(OptionsResolver $resolver)
+        {
+            $resolver->setDefaults([
+                // the example below will create a CallbackChoiceLoader from the callable
+                'choice_loader' => ChoiceList::lazy($this, function() {
+                    return StaticClass::getConstants();
+                }),
+
+                // you can pass your own loader as well, depending on other options
+                'some_key' => null,
+                'choice_loader' => function (Options $options) {
+                    return ChoiceList::loader(
+                        // pass the instance of the type or type extension which is
+                        // currently configuring the choice list as first argument
+                        $this,
+                        // pass the other option to the loader
+                        new CustomChoiceLoader($options['some_key']),
+                        // ensure the type stores a loader per key
+                        // by using the special third argument "$vary"
+                        // an array containing anything that "changes" the loader
+                        [$options['some_key']]
+                    );
+                },
+            ]);
+        }
+    }