[DX] Filter PropertyInfo Extractors with Interfaces

Use a single service tag to filter a central source of information extractor instances. Since PropertyInfo requires PHP 5.5+, use ::class constant to negate the use of class constants or strings.
symfony · zanbaldwin · Dec 6, 2015 · Dec 7, 2015 · 159fd83a15bfc9ff0e4fcdfb650cb49de43011a9
commit 159fd83a15bfc9ff0e4fcdfb650cb49de43011a9
diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/PropertyInfoPass.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/PropertyInfoPass.php
@@ -31,17 +31,8 @@ public function process(ContainerBuilder $container)
             return;
         }
 
-        $listExtractors = $this->findAndSortTaggedServices('property_info.list_extractor', $container);
-        $container->getDefinition('property_info')->replaceArgument(0, $listExtractors);
-
-        $typeExtractors = $this->findAndSortTaggedServices('property_info.type_extractor', $container);
-        $container->getDefinition('property_info')->replaceArgument(1, $typeExtractors);
-
-        $descriptionExtractors = $this->findAndSortTaggedServices('property_info.description_extractor', $container);
-        $container->getDefinition('property_info')->replaceArgument(2, $descriptionExtractors);
-
-        $accessExtractors = $this->findAndSortTaggedServices('property_info.access_extractor', $container);
-        $container->getDefinition('property_info')->replaceArgument(3, $accessExtractors);
+        $extractors = $this->findAndSortTaggedServices('property_info.extractor', $container);
+        $container->getDefinition('property_info')->replaceArgument(0, $extractors);
     }
 
     /**

diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
@@ -1007,8 +1007,7 @@ private function registerPropertyInfoConfiguration(array $config, ContainerBuild
 
         if (class_exists('phpDocumentor\Reflection\ClassReflector')) {
             $definition = $container->register('property_info.php_doc_extractor', 'Symfony\Component\PropertyInfo\Extractor\PhpDocExtractor');
-            $definition->addTag('property_info.description_extractor', array('priority' => -1000));
-            $definition->addTag('property_info.type_extractor', array('priority' => -1001));
+            $definition->addTag('property_info.extractor', array('priority' => -1001));
         }
     }
 

diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/property_info.xml b/src/Symfony/Bundle/FrameworkBundle/Resources/config/property_info.xml
@@ -7,16 +7,11 @@
     <services>
         <service id="property_info" class="Symfony\Component\PropertyInfo\PropertyInfoExtractor" >
             <argument type="collection" />
-            <argument type="collection" />
-            <argument type="collection" />
-            <argument type="collection" />
         </service>
 
         <!-- Extractor -->
         <service id="property_info.reflection_extractor" class="Symfony\Component\PropertyInfo\Extractor\ReflectionExtractor" public="false">
-            <tag name="property_info.list_extractor" priority="-1000" />
-            <tag name="property_info.type_extractor" priority="-1000" />
-            <tag name="property_info.access_extractor" priority="-1000" />
+            <tag name="property_info.extractor" priority="-1000" />
         </service>
     </services>
 </container>
@@ -0,0 +1,12 @@
+<?php
+
+namespace Symfony\Component\PropertyInfo;
+
+/**
+ * Interface ExtractorInterface.
+ *
+ * @author Zander Baldwin <hello@zanderbaldwin.com>
+ */
+interface ExtractorInterface
+{
+}
@@ -16,7 +16,7 @@
  *
  * @author Kévin Dunglas <dunglas@gmail.com>
  */
-interface PropertyAccessExtractorInterface
+interface PropertyAccessExtractorInterface extends ExtractorInterface
 {
     /**
      * Is the property readable?

@@ -16,7 +16,7 @@
  *
  * @author Kévin Dunglas <dunglas@gmail.com>
  */
-interface PropertyDescriptionExtractorInterface
+interface PropertyDescriptionExtractorInterface extends ExtractorInterface
 {
     /**
      * Gets the short description of the property.

@@ -19,102 +19,118 @@
 class PropertyInfoExtractor implements PropertyInfoExtractorInterface
 {
     /**
-     * @var PropertyListExtractorInterface[]
+     * @var \SplObjectStorage
      */
-    private $listExtractors;
+    private $extractors;
 
     /**
-     * @var PropertyTypeExtractorInterface[]
+     * @param ExtractorInterface[] $extractors
      */
-    private $typeExtractors;
-
-    /**
-     * @var PropertyDescriptionExtractorInterface[]
-     */
-    private $descriptionExtractors;
-
-    /**
-     * @var PropertyAccessExtractorInterface[]
-     */
-    private $accessExtractors;
+    public function __construct(array $extractors = array())
+    {
+        $this->extractors = new \SplObjectStorage();
+        foreach ($extractors as $extractor) {
+            $this->addExtractor($extractor);
+        }
+    }
 
     /**
-     * @param PropertyListExtractorInterface[]        $listExtractors
-     * @param PropertyTypeExtractorInterface[]        $typeExtractors
-     * @param PropertyDescriptionExtractorInterface[] $descriptionExtractors
-     * @param PropertyAccessExtractorInterface[]      $accessExtractors
+     * {@inheritdoc}
      */
-    public function __construct(array $listExtractors = array(), array $typeExtractors = array(),  array $descriptionExtractors = array(), array $accessExtractors = array())
+    public function addExtractor(ExtractorInterface $extractor)
     {
-        $this->listExtractors = $listExtractors;
-        $this->typeExtractors = $typeExtractors;
-        $this->descriptionExtractors = $descriptionExtractors;
-        $this->accessExtractors = $accessExtractors;
+        $this->extractors->attach($extractor);
     }
 
     /**
      * {@inheritdoc}
      */
     public function getProperties($class, array $context = array())
     {
-        return $this->extract($this->listExtractors, 'getProperties', array($class, $context));
+        return $this->extract(
+            PropertyListExtractorInterface::class,
+            'getProperties',
+            array($class, $context)
+        );
     }
 
     /**
      * {@inheritdoc}
      */
     public function getShortDescription($class, $property, array $context = array())
     {
-        return $this->extract($this->descriptionExtractors, 'getShortDescription', array($class, $property, $context));
+        return $this->extract(
+            PropertyDescriptionExtractorInterface::class,
+            'getShortDescription',
+            array($class, $property, $context)
+        );
     }
 
     /**
      * {@inheritdoc}
      */
     public function getLongDescription($class, $property, array $context = array())
     {
-        return $this->extract($this->descriptionExtractors, 'getLongDescription', array($class, $property, $context));
+        return $this->extract(
+            PropertyDescriptionExtractorInterface::class,
+            'getLongDescription',
+            array($class, $property, $context)
+        );
     }
 
     /**
      * {@inheritdoc}
      */
     public function getTypes($class, $property, array $context = array())
     {
-        return $this->extract($this->typeExtractors, 'getTypes', array($class, $property, $context));
+        return $this->extract(
+            PropertyTypeExtractorInterface::class,
+            'getTypes',
+            array($class, $property, $context)
+        );
     }
 
     /**
      * {@inheritdoc}
      */
     public function isReadable($class, $property, array $context = array())
     {
-        return $this->extract($this->accessExtractors, 'isReadable', array($class, $property, $context));
+        return $this->extract(
+            PropertyAccessExtractorInterface::class,
+            'isReadable',
+            array($class, $property, $context)
+        );
     }
 
     /**
      * {@inheritdoc}
      */
     public function isWritable($class, $property, array $context = array())
     {
-        return $this->extract($this->accessExtractors, 'isWritable', array($class, $property, $context));
+        return $this->extract(
+            PropertyAccessExtractorInterface::class,
+            'isWritable',
+            array($class, $property, $context)
+        );
     }
 
     /**
      * Iterates over registered extractors and return the first value found.
      *
-     * @param array  $extractors
+     * @param string $interfaceFilter
      * @param string $method
      * @param array  $arguments
      *
      * @return mixed
      */
-    private function extract(array $extractors, $method, array $arguments)
+    private function extract($interfaceFilter, $method, array $arguments)
     {
-        foreach ($extractors as $extractor) {
-            $value = call_user_func_array(array($extractor, $method), $arguments);
-            if (null !== $value) {
-                return $value;
+        foreach ($this->extractors as $extractor) {
+            if ($extractor instanceof $interfaceFilter) {
+                $value = call_user_func_array(array($extractor, $method), $arguments);
+                if (null !== $value) {
+                    return $value;
+                }
             }
         }
     }

@@ -20,4 +20,8 @@
  */
 interface PropertyInfoExtractorInterface extends PropertyTypeExtractorInterface, PropertyDescriptionExtractorInterface, PropertyAccessExtractorInterface, PropertyListExtractorInterface
 {
+    /**
+     * @param ExtractorInterface $extractor
+     */
+    public function addExtractor(ExtractorInterface $extractor);
 }
@@ -16,7 +16,7 @@
  *
  * @author Kévin Dunglas <dunglas@gmail.com>
  */
-interface PropertyListExtractorInterface
+interface PropertyListExtractorInterface extends ExtractorInterface
 {
     /**
      * Gets the list of properties available for the given class.

@@ -16,7 +16,7 @@
  *
  * @author Kévin Dunglas <dunglas@gmail.com>
  */
-interface PropertyTypeExtractorInterface
+interface PropertyTypeExtractorInterface extends ExtractorInterface
 {
     /**
      * Gets types of a property.

diff --git a/src/Symfony/Component/PropertyInfo/Tests/PropertyInfoExtractorTest.php b/src/Symfony/Component/PropertyInfo/Tests/PropertyInfoExtractorTest.php
@@ -28,8 +28,7 @@ class PropertyInfoExtractorTest extends \PHPUnit_Framework_TestCase
 
     public function setUp()
     {
-        $extractors = array(new NullExtractor(), new DummyExtractor());
-        $this->propertyInfo = new PropertyInfoExtractor($extractors, $extractors, $extractors, $extractors);
+        $this->propertyInfo = new PropertyInfoExtractor(array(new NullExtractor(), new DummyExtractor()));
     }
 
     public function testInstanceOf()
@@ -38,6 +37,7 @@ public function testInstanceOf()
         $this->assertInstanceOf('Symfony\Component\PropertyInfo\PropertyTypeExtractorInterface', $this->propertyInfo);
         $this->assertInstanceOf('Symfony\Component\PropertyInfo\PropertyDescriptionExtractorInterface', $this->propertyInfo);
         $this->assertInstanceOf('Symfony\Component\PropertyInfo\PropertyAccessExtractorInterface', $this->propertyInfo);
+        $this->assertInstanceOf('Symfony\Component\PropertyInfo\ExtractorInterface', $this->propertyInfo);
     }
 
     public function testGetShortDescription()