feature #31390 [Serializer] UnwrappingDenormalizer (nonanerz)

This PR was merged into the 5.1-dev branch.

Discussion
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[Serializer] UnwrappingDenormalizer

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

UnwrappingDenormalizer, registered with very high priority. Unwrapping the data if UNWRAP_PATH is provided.

Very often some APIs give nested responses in which we need only the child object. With UnwrappingDenormalizer we can get the needed object without creating unnecessary Model class that we don't really need.

Regarding to symfony/symfony#28887 and symfony/symfony#30894

Usage:

`$serialiser->deserialize('{"baz": {"foo": "bar", "inner": {"title": "value", "numbers": [5,3]}}}', Object::class, ['UnwrappingDenormalizer::UNWRAP_PATH' => '[baz][inner]'])`

Commits
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00d103d5f7 UnwrappingDenormalizer

Author: fabpot

DependencyInjection/FrameworkExtension.php

@@ -119,6 +119,7 @@
 use Symfony\Component\Serializer\Encoder\EncoderInterface;
 use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+use Symfony\Component\Serializer\Normalizer\UnwrappingDenormalizer;
 use Symfony\Component\Stopwatch\Stopwatch;
 use Symfony\Component\String\LazyString;
 use Symfony\Component\String\Slugger\SluggerInterface;
@@ -1471,6 +1472,10 @@ private function registerSerializerConfiguration(array $config, ContainerBuilder
             $container->removeDefinition('serializer.encoder.yaml');
         }
 
+        if (!class_exists(UnwrappingDenormalizer::class)) {
+            $container->removeDefinition('serializer.denormalizer.unwrapping');
+        }
+
         $serializerLoaders = [];
         if (isset($config['enable_annotations']) && $config['enable_annotations']) {
             if (!$this->annotationsConfigEnabled) {

Resources/config/serializer.xml

@@ -70,6 +70,12 @@
             <tag name="serializer.normalizer" priority="-890" />
         </service>
 
+        <service id="serializer.denormalizer.unwrapping" class="Symfony\Component\Serializer\Normalizer\UnwrappingDenormalizer">
+            <argument type="service" id="serializer.property_accessor" />
+            <!-- Run before serializer.normalizer.object -->
+            <tag name="serializer.normalizer" priority="1000" />
+        </service>
+
         <service id="serializer.normalizer.object" class="Symfony\Component\Serializer\Normalizer\ObjectNormalizer">
             <argument type="service" id="serializer.mapping.class_metadata_factory" />
             <argument type="service" id="serializer.name_converter.metadata_aware" />