[DependencyInjection] added support for expressions in the service container

src/Symfony/Component/DependencyInjection/CHANGELOG.md

@@ -4,6 +4,7 @@ CHANGELOG
 2.4.0
 -----
 
+ * added support for expressions in service definitions
  * added ContainerAwareTrait to add default container aware behavior to a class
 
 2.2.0

src/Symfony/Component/DependencyInjection/ContainerBuilder.php

@@ -24,6 +24,8 @@ use Symfony\Component\Config\Resource\FileResource;
 use Symfony\Component\Config\Resource\ResourceInterface;
 use Symfony\Component\DependencyInjection\LazyProxy\Instantiator\InstantiatorInterface;
 use Symfony\Component\DependencyInjection\LazyProxy\Instantiator\RealServiceInstantiator;
+use Symfony\Component\DependencyInjection\ExpressionLanguage;
+use Symfony\Component\ExpressionLanguage\Expression;
 
 /**
  * ContainerBuilder is a DI container that provides an API to easily describe services.
@@ -78,6 +80,11 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
      */
     private $proxyInstantiator;
 
+    /**
+     * @var ExpressionLanguage|null
+     */
+    private $expressionLanguage;
+
     /**
      * Sets the track resources flag.
      *
@@ -983,11 +990,12 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
     }
 
     /**
-     * Replaces service references by the real service instance.
+     * Replaces service references by the real service instance and evaluates expressions.
      *
      * @param mixed $value A value
      *
-     * @return mixed The same value with all service references replaced by the real service instances
+     * @return mixed The same value with all service references replaced by
+     *               the real service instances and all expressions evaluated
      */
     public function resolveServices($value)
     {
@@ -999,6 +1007,8 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
             $value = $this->get((string) $value, $value->getInvalidBehavior());
         } elseif ($value instanceof Definition) {
             $value = $this->createService($value, null);
+        } elseif ($value instanceof Expression) {
+            $value = $this->getExpressionLanguage()->evaluate($value, array('this' => $this));
         }
 
         return $value;
@@ -1149,4 +1159,16 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
             }
         }
     }
+
+    private function getExpressionLanguage()
+    {
+        if (null === $this->expressionLanguage) {
+            if (!class_exists('Symfony\Component\ExpressionLanguage\ExpressionLanguage')) {
+                throw new RuntimeException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed.');
+            }
+            $this->expressionLanguage = new ExpressionLanguage();
+        }
+
+        return $this->expressionLanguage;
+    }
 }

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

@@ -23,6 +23,8 @@ use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\Exception\ServiceCircularReferenceException;
 use Symfony\Component\DependencyInjection\LazyProxy\PhpDumper\DumperInterface as ProxyDumper;
 use Symfony\Component\DependencyInjection\LazyProxy\PhpDumper\NullDumper;
+use Symfony\Component\DependencyInjection\ExpressionLanguage;
+use Symfony\Component\ExpressionLanguage\Expression;
 
 /**
  * PhpDumper dumps a service container as a PHP class.
@@ -51,6 +53,7 @@ class PhpDumper extends Dumper
     private $referenceVariables;
     private $variableCount;
     private $reservedVariables = array('instance', 'class');
+    private $expressionLanguage;
 
     /**
      * @var \Symfony\Component\DependencyInjection\LazyProxy\PhpDumper\DumperInterface
@@ -1197,6 +1200,8 @@ EOF;
             }
 
             return $this->getServiceCall((string) $value, $value);
+        } elseif ($value instanceof Expression) {
+            return $this->getExpressionLanguage()->compile((string) $value, array('this'));
         } elseif ($value instanceof Parameter) {
             return $this->dumpParameter($value);
         } elseif (true === $interpolate && is_string($value)) {
@@ -1319,4 +1324,16 @@ EOF;
             return $name;
         }
     }
+
+    private function getExpressionLanguage()
+    {
+        if (null === $this->expressionLanguage) {
+            if (!class_exists('Symfony\Component\ExpressionLanguage\ExpressionLanguage')) {
+                throw new RuntimeException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed.');
+            }
+            $this->expressionLanguage = new ExpressionLanguage();
+        }
+
+        return $this->expressionLanguage;
+    }
 }

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

@@ -17,6 +17,7 @@ use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Component\DependencyInjection\Alias;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
+use Symfony\Component\ExpressionLanguage\Expression;
 
 /**
  * XmlDumper dumps a service container as an XML string.
@@ -259,6 +260,10 @@ class XmlDumper extends Dumper
             } elseif ($value instanceof Definition) {
                 $element->setAttribute('type', 'service');
                 $this->addService($value, null, $element);
+            } elseif ($value instanceof Expression) {
+                $element->setAttribute('type', 'expression');
+                $text = $this->document->createTextNode(self::phpToXml((string) $value));
+                $element->appendChild($text);
             } else {
                 if (in_array($value, array('null', 'true', 'false'), true)) {
                     $element->setAttribute('type', 'string');

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

@@ -19,6 +19,7 @@ use Symfony\Component\DependencyInjection\Parameter;
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\DependencyInjection\Exception\RuntimeException;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\ExpressionLanguage\Expression;
 
 /**
  * YamlDumper dumps a service container as a YAML string.
@@ -231,6 +232,8 @@ class YamlDumper extends Dumper
             return $this->getServiceCall((string) $value, $value);
         } elseif ($value instanceof Parameter) {
             return $this->getParameterCall((string) $value);
+        } elseif ($value instanceof Expression) {
+            return $this->getExpressionCall((string) $value);
         } elseif (is_object($value) || is_resource($value)) {
             throw new RuntimeException('Unable to dump a service container if a parameter is an object or a resource.');
         }
@@ -267,6 +270,11 @@ class YamlDumper extends Dumper
         return sprintf('%%%s%%', $id);
     }
 
+    private function getExpressionCall($expression)
+    {
+        return sprintf('@=%s', $expression);
+    }
+
     /**
      * Prepares parameters.
      *

src/Symfony/Component/DependencyInjection/ExpressionLanguage.php

@@ -0,0 +1,42 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\DependencyInjection;
+
+use Symfony\Component\ExpressionLanguage\ExpressionLanguage as BaseExpressionLanguage;
+
+/**
+ * Adds some function to the default ExpressionLanguage.
+ *
+ * To get a service, use service('request').
+ * To get a parameter, use parameter('kernel.debug').
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class ExpressionLanguage extends BaseExpressionLanguage
+{
+    protected function registerFunctions()
+    {
+        parent::registerFunctions();
+
+        $this->addFunction('service', function ($arg) {
+            return sprintf('$this->get(%s)', $arg);
+        }, function (array $variables, $value) {
+            return $variables['container']->get($value);
+        });
+
+        $this->addFunction('parameter', function ($arg) {
+            return sprintf('$this->getParameter(%s)', $arg);
+        }, function (array $variables, $value) {
+            return $variables['container']->getParameter($value);
+        });
+    }
+}

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

@@ -19,6 +19,7 @@ use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\DependencyInjection\Exception\InvalidArgumentException;
 use Symfony\Component\Config\Resource\FileResource;
 use Symfony\Component\Yaml\Parser as YamlParser;
+use Symfony\Component\ExpressionLanguage\Expression;
 
 /**
  * YamlFileLoader loads YAML files service definitions.
@@ -311,6 +312,8 @@ class YamlFileLoader extends FileLoader
     {
         if (is_array($value)) {
             $value = array_map(array($this, 'resolveServices'), $value);
+        } elseif (is_string($value) &&  0 === strpos($value, '@=')) {
+            return new Expression(substr($value, 2));
         } elseif (is_string($value) &&  0 === strpos($value, '@')) {
             if (0 === strpos($value, '@@')) {
                 $value = substr($value, 1);

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

@@ -164,6 +164,7 @@
     <xsd:restriction base="xsd:string">
       <xsd:enumeration value="collection" />
       <xsd:enumeration value="service" />
+      <xsd:enumeration value="expression" />
       <xsd:enumeration value="string" />
       <xsd:enumeration value="constant" />
     </xsd:restriction>

src/Symfony/Component/DependencyInjection/SimpleXMLElement.php

@@ -12,6 +12,7 @@
 namespace Symfony\Component\DependencyInjection;
 
 use Symfony\Component\Config\Util\XmlUtils;
+use Symfony\Component\ExpressionLanguage\Expression;
 
 /**
  * SimpleXMLElement class.
@@ -77,6 +78,9 @@ class SimpleXMLElement extends \SimpleXMLElement
 
                     $arguments[$key] = new Reference((string) $arg['id'], $invalidBehavior, $strict);
                     break;
+                case 'expression':
+                    $arguments[$key] = new Expression((string) $arg);
+                    break;
                 case 'collection':
                     $arguments[$key] = $arg->getArgumentsAsPhp($name, false);
                     break;

src/Symfony/Component/DependencyInjection/Tests/ContainerBuilderTest.php

@@ -25,6 +25,7 @@ use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\DependencyInjection\ParameterBag\ParameterBag;
 use Symfony\Component\DependencyInjection\Scope;
 use Symfony\Component\Config\Resource\FileResource;
+use Symfony\Component\ExpressionLanguage\Expression;
 
 class ContainerBuilderTest extends \PHPUnit_Framework_TestCase
 {
@@ -377,6 +378,15 @@ class ContainerBuilderTest extends \PHPUnit_Framework_TestCase
         $builder->get('foo');
     }
 
+    public function testCreateServiceWithExpression()
+    {
+        $builder = new ContainerBuilder();
+        $builder->setParameter('bar', 'bar');
+        $builder->register('bar', 'BarClass');
+        $builder->register('foo', 'FooClass')->addArgument(array('foo' => new Expression('service("bar").foo ~ parameter("bar")')));
+        $this->assertEquals('foobar', $builder->get('foo')->arguments['foo']);
+    }
+
     /**
      * @covers Symfony\Component\DependencyInjection\ContainerBuilder::resolveServices
      */
@@ -386,6 +396,7 @@ class ContainerBuilderTest extends \PHPUnit_Framework_TestCase
         $builder->register('foo', 'FooClass');
         $this->assertEquals($builder->get('foo'), $builder->resolveServices(new Reference('foo')), '->resolveServices() resolves service references to service instances');
         $this->assertEquals(array('foo' => array('foo', $builder->get('foo'))), $builder->resolveServices(array('foo' => array('foo', new Reference('foo')))), '->resolveServices() resolves service references to service instances in nested arrays');
+        $this->assertEquals($builder->get('foo'), $builder->resolveServices(new Expression('service("foo")')), '->resolveServices() resolves expressions');
     }
 
     /**

src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container9.php

@@ -6,6 +6,7 @@ use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\DependencyInjection\Parameter;
+use Symfony\Component\ExpressionLanguage\Expression;
 
 $container = new ContainerBuilder();
 $container->
@@ -50,7 +51,8 @@ $container->
     addMethodCall('setBar', array(new Reference('foo')))->
     addMethodCall('setBar', array(new Reference('foo2', ContainerInterface::NULL_ON_INVALID_REFERENCE)))->
     addMethodCall('setBar', array(new Reference('foo3', ContainerInterface::IGNORE_ON_INVALID_REFERENCE)))->
-    addMethodCall('setBar', array(new Reference('foobaz', ContainerInterface::IGNORE_ON_INVALID_REFERENCE)))
+    addMethodCall('setBar', array(new Reference('foobaz', ContainerInterface::IGNORE_ON_INVALID_REFERENCE)))->
+    addMethodCall('setBar', array(new Expression('service("foo").foo() ~ parameter("foo")')))
 ;
 $container->
     register('factory_service', 'Bar')->

src/Symfony/Component/DependencyInjection/Tests/Fixtures/includes/classes.php

@@ -8,6 +8,7 @@ function sc_configure($instance)
 class BarClass
 {
     protected $baz;
+    public $foo = 'foo';
 
     public function setBaz(BazClass $baz)
     {

src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9.php

@@ -198,6 +198,7 @@ class ProjectServiceContainer extends Container
         if ($this->has('foobaz')) {
             $instance->setBar($this->get('foobaz', ContainerInterface::NULL_ON_INVALID_REFERENCE));
         }
+        $instance->setBar(($this->get("foo")->foo() . $this->getParameter("foo")));
 
         return $instance;
     }

src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php

@@ -203,6 +203,7 @@ class ProjectServiceContainer extends Container
 
         $instance->setBar($this->get('foo'));
         $instance->setBar(NULL);
+        $instance->setBar(($this->get("foo")->foo() . $this->getParameter("foo")));
 
         return $instance;
     }

src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services6.xml

@@ -32,6 +32,9 @@
     </service>
     <service id="method_call1" class="FooClass">
       <call method="setBar" />
+      <call method="setBar">
+        <argument type="expression">service("foo").foo() ~ parameter("foo")</argument>
+      </call>
     </service>
     <service id="method_call2" class="FooClass">
       <call method="setBar">

src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services9.xml

@@ -49,6 +49,9 @@
       <call method="setBar">
         <argument type="service" id="foobaz" on-invalid="ignore"/>
       </call>
+      <call method="setBar">
+        <argument type="expression">service("foo").foo() ~ parameter("foo")</argument>
+      </call>
     </service>
     <service id="factory_service" class="Bar" factory-method="getInstance" factory-service="foo.baz"/>
     <service id="foo_with_inline" class="Foo">

src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services6.yml

@@ -15,6 +15,7 @@ services:
         calls:
             - [ setBar, [] ]
             - [ setBar ]
+            - [ setBar, ['@=service("foo").foo() ~ parameter("foo")'] ]
     method_call2:
         class: FooClass
         calls:

src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services9.yml

@@ -38,6 +38,7 @@ services:
             - [setBar, ['@?foo2']]
             - [setBar, ['@?foo3']]
             - [setBar, ['@?foobaz']]
+            - [setBar, ['@=service("foo").foo() ~ parameter("foo")']]
 
     factory_service:
         class: Bar

src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php

@@ -22,6 +22,7 @@ use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
 use Symfony\Component\DependencyInjection\Loader\IniFileLoader;
 use Symfony\Component\Config\Loader\LoaderResolver;
 use Symfony\Component\Config\FileLocator;
+use Symfony\Component\ExpressionLanguage\Expression;
 
 class XmlFileLoaderTest extends \PHPUnit_Framework_TestCase
 {
@@ -211,7 +212,7 @@ class XmlFileLoaderTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('sc_configure', $services['configurator1']->getConfigurator(), '->load() parses the configurator tag');
         $this->assertEquals(array(new Reference('baz', ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE, false), 'configure'), $services['configurator2']->getConfigurator(), '->load() parses the configurator tag');
         $this->assertEquals(array('BazClass', 'configureStatic'), $services['configurator3']->getConfigurator(), '->load() parses the configurator tag');
-        $this->assertEquals(array(array('setBar', array())), $services['method_call1']->getMethodCalls(), '->load() parses the method_call tag');
+        $this->assertEquals(array(array('setBar', array()), array('setBar', array(new Expression('service("foo").foo() ~ parameter("foo")')))), $services['method_call1']->getMethodCalls(), '->load() parses the method_call tag');
         $this->assertEquals(array(array('setBar', array('foo', new Reference('foo'), array(true, false)))), $services['method_call2']->getMethodCalls(), '->load() parses the method_call tag');
         $this->assertNull($services['factory_service']->getClass());
         $this->assertEquals('getInstance', $services['factory_service']->getFactoryMethod());

src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php

@@ -20,6 +20,7 @@ use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
 use Symfony\Component\DependencyInjection\Loader\IniFileLoader;
 use Symfony\Component\Config\Loader\LoaderResolver;
 use Symfony\Component\Config\FileLocator;
+use Symfony\Component\ExpressionLanguage\Expression;
 
 class YamlFileLoaderTest extends \PHPUnit_Framework_TestCase
 {
@@ -113,7 +114,7 @@ class YamlFileLoaderTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('sc_configure', $services['configurator1']->getConfigurator(), '->load() parses the configurator tag');
         $this->assertEquals(array(new Reference('baz'), 'configure'), $services['configurator2']->getConfigurator(), '->load() parses the configurator tag');
         $this->assertEquals(array('BazClass', 'configureStatic'), $services['configurator3']->getConfigurator(), '->load() parses the configurator tag');
-        $this->assertEquals(array(array('setBar', array()), array('setBar', array())), $services['method_call1']->getMethodCalls(), '->load() parses the method_call tag');
+        $this->assertEquals(array(array('setBar', array()), array('setBar', array()), array('setBar', array(new Expression('service("foo").foo() ~ parameter("foo")')))), $services['method_call1']->getMethodCalls(), '->load() parses the method_call tag');
         $this->assertEquals(array(array('setBar', array('foo', new Reference('foo'), array(true, false)))), $services['method_call2']->getMethodCalls(), '->load() parses the method_call tag');
         $this->assertEquals('baz_factory', $services['factory_service']->getFactoryService());
 

src/Symfony/Component/DependencyInjection/composer.json

@@ -20,7 +20,8 @@
     },
     "require-dev": {
         "symfony/yaml": "~2.0",
-        "symfony/config": "~2.2"
+        "symfony/config": "~2.2",
+        "symfony/expression-language": "~2.4"
     },
     "suggest": {
         "symfony/yaml": "",