[PropertyInfo] Add ConstructorExtractor documentation

Author: alexandre-daubois

components/property_info.rst

@@ -483,6 +483,38 @@ with the ``property_info`` service in the Symfony Framework::
  // Type information.
  $doctrineExtractor->getTypes($class, $property);
 
+ConstructorExtractor
+~~~~~~~~~~~~~~~~~~~~
+
+The :class:`Symfony\\Component\\PropertyInfo\\Extractor\\ConstructorExtractor`
+tries to extract properties information by using either the
+:class:`Symfony\\Component\\PropertyInfo\\Extractor\\PhpStanExtractor` or
+the :class:`Symfony\\Component\\PropertyInfo\\Extractor\\ReflectionExtractor`
+on the constructor arguments::
+
+ // src/Domain/Foo.php
+ class Foo
+ {
+ private $bar;
+
+ public function __construct(string $bar)
+ {
+ $this->bar = $bar;
+ }
+ }
+
+ // Extraction.php
+ use Symfony\Component\PropertyInfo\Extractor\ConstructorExtractor;
+ use App\Domain\Foo;
+
+ $constructorExtractor = new ConstructorExtractor([new ReflectionExtractor()]);
+ $constructorExtractor->getTypes(Foo::class, 'bar')[0]->getBuiltinType(); // returns 'string'
+
+.. versionadded:: 5.2
+
+ The :class:`Symfony\\Component\\PropertyInfo\\Extractor\\ConstructorExtractor`
+ was introduced in Symfony 5.2.
+
 .. _`components-property-information-extractors-creation`:
 
 Creating Your Own Extractors