adds synthetic attribute to definitions

This attribute can be used to hint that the service is being injected
dynamically at runtime, and not constructed by the DIC.

src/Symfony/Bundle/FrameworkBundle/Resources/config/services.xml

@@ -35,7 +35,7 @@
             This service definition only defines the scope of the request.
             It is used to check references scope.
         -->
-        <service id="request" scope="request" />
+        <service id="request" scope="request" synthetic="true" />
 
         <service id="response" class="%response.class%" scope="prototype">
             <call method="setCharset">

src/Symfony/Component/DependencyInjection/Definition.php

@@ -28,6 +28,7 @@ class Definition
     protected $configurator;
     protected $tags;
     protected $public;
+    protected $synthetic;
 
     /**
      * Constructor.
@@ -43,6 +44,7 @@ class Definition
         $this->scope = ContainerInterface::SCOPE_CONTAINER;
         $this->tags = array();
         $this->public = true;
+        $this->synthetic = false;
     }
 
     /**
@@ -377,6 +379,32 @@ class Definition
         return $this->public;
     }
 
+    /**
+     * Sets whether this definition is synthetic, that is not constructed by the
+     * container, but dynamically injected.
+     *
+     * @param Boolean $boolean
+     *
+     * @return Definition the current instance
+     */
+    public function setSynthetic($boolean)
+    {
+        $this->synthetic = (Boolean) $boolean;
+
+        return $this;
+    }
+
+    /**
+     * Whether this definition is synthetic, that is not constructed by the
+     * container, but dynamically injected.
+     *
+     * @return Boolean
+     */
+    public function isSynthetic()
+    {
+        return $this->synthetic;
+    }
+
     /**
      * Sets a configurator to call after the service is fully initialized.
      *

src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php

@@ -394,7 +394,9 @@ EOF;
         $this->variableCount = 0;
 
         $return = '';
-        if ($class = $definition->getClass()) {
+        if ($definition->isSynthetic()) {
+            $return = sprintf('@throws \RuntimeException always since this service is expected to be injected dynamically');
+        } else if ($class = $definition->getClass()) {
             $return = sprintf("@return %s A %s instance.", 0 === strpos($class, '%') ? 'Object' : $class, $class);
         } elseif ($definition->getFactoryService()) {
             $return = sprintf('@return Object An instance returned by %s::%s().', $definition->getFactoryService(), $definition->getFactoryMethod());
@@ -443,16 +445,20 @@ EOF;
 EOF;
         }
 
-        $code .=
-            $this->addServiceInclude($id, $definition).
-            $this->addServiceLocalTempVariables($id, $definition).
-            $this->addServiceInlinedDefinitions($id, $definition).
-            $this->addServiceInstance($id, $definition).
-            $this->addServiceInlinedDefinitionsSetup($id, $definition).
-            $this->addServiceMethodCalls($id, $definition).
-            $this->addServiceConfigurator($id, $definition).
-            $this->addServiceReturn($id, $definition)
-        ;
+        if ($definition->isSynthetic()) {
+            $code .= sprintf("        throw new \RuntimeException('You have requested a synthetic service (\"%s\"). The DIC does not know how to construct this service.');\n    }\n", $id);
+        } else {
+            $code .=
+                $this->addServiceInclude($id, $definition).
+                $this->addServiceLocalTempVariables($id, $definition).
+                $this->addServiceInlinedDefinitions($id, $definition).
+                $this->addServiceInstance($id, $definition).
+                $this->addServiceInlinedDefinitionsSetup($id, $definition).
+                $this->addServiceMethodCalls($id, $definition).
+                $this->addServiceConfigurator($id, $definition).
+                $this->addServiceReturn($id, $definition)
+            ;
+        }
 
         $this->definitionVariables = null;
         $this->referenceVariables = null;

src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php

@@ -12,9 +12,7 @@
 namespace Symfony\Component\DependencyInjection\Loader;
 
 use Symfony\Component\DependencyInjection\ContainerInterface;
-
 use Symfony\Component\DependencyInjection\Alias;
-
 use Symfony\Component\DependencyInjection\InterfaceInjector;
 use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Component\DependencyInjection\Reference;
@@ -139,7 +137,7 @@ class XmlFileLoader extends FileLoader
 
         $definition = new Definition();
 
-        foreach (array('class', 'scope', 'public', 'factory-method', 'factory-service') as $key) {
+        foreach (array('class', 'scope', 'public', 'factory-method', 'factory-service', 'synthetic') as $key) {
             if (isset($service[$key])) {
                 $method = 'set'.str_replace('-', '', $key);
                 $definition->$method((string) $service->getAttributeAsPhp($key));

src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php

@@ -12,7 +12,6 @@
 namespace Symfony\Component\DependencyInjection\Loader;
 
 use Symfony\Component\DependencyInjection\Alias;
-
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\DependencyInjection\InterfaceInjector;
 use Symfony\Component\DependencyInjection\Definition;
@@ -148,6 +147,10 @@ class YamlFileLoader extends FileLoader
             $definition->setScope($service['scope']);
         }
 
+        if (isset($service['synthetic'])) {
+            $definition->setSynthetic($service['synthetic']);
+        }
+
         if (isset($service['public'])) {
             $definition->setPublic($service['public']);
         }

src/Symfony/Component/DependencyInjection/Loader/schema/dic/services/services-1.0.xsd

@@ -103,6 +103,7 @@
     <xsd:attribute name="class" type="xsd:string" />
     <xsd:attribute name="scope" type="xsd:string" />
     <xsd:attribute name="public" type="boolean" />
+    <xsd:attribute name="synthetic" type="boolean" />
     <xsd:attribute name="factory-method" type="xsd:string" />
     <xsd:attribute name="factory-service" type="xsd:string" />
     <xsd:attribute name="alias" type="xsd:string" />

tests/Symfony/Tests/Component/DependencyInjection/DefinitionTest.php

@@ -125,6 +125,18 @@ class DefinitionTest extends \PHPUnit_Framework_TestCase
         $this->assertFalse($def->isPublic(), '->isPublic() returns false if the instance must not be public.');
     }
 
+    /**
+     * @covers Symfony\Component\DependencyInjection\Definition::setSynthetic
+     * @covers Symfony\Component\DependencyInjection\Definition::isSynthetic
+     */
+    public function testSetIsSynthetic()
+    {
+        $def = new Definition('stdClass');
+        $this->assertFalse($def->isSynthetic(), '->isSynthetic() returns false by default');
+        $this->assertSame($def, $def->setSynthetic(true), '->setSynthetic() implements a fluent interface');
+        $this->assertTrue($def->isSynthetic(), '->isSynthetic() returns true if the instance must not be public.');
+    }
+
     /**
      * @covers Symfony\Component\DependencyInjection\Definition::setConfigurator
      * @covers Symfony\Component\DependencyInjection\Definition::getConfigurator