[DependencyInjection] Add argument type closure to help passing closures to services

Author: nicolas-grekas

CHANGELOG.md

@@ -9,6 +9,7 @@ CHANGELOG
  * Add an `env` function to the expression language provider
  * Add an `Autowire` attribute to tell a parameter how to be autowired
  * Allow using expressions as service factories
+ * Add argument type `closure` to help passing closures to services
  * Deprecate `ReferenceSetArgumentTrait`
 
 6.0

Dumper/PhpDumper.php

@@ -1132,6 +1132,15 @@ private function addNewInstance(Definition $definition, string $return = '', str
         if (null !== $definition->getFactory()) {
             $callable = $definition->getFactory();
 
+            if (['Closure', 'fromCallable'] === $callable && [0] === array_keys($definition->getArguments())) {
+                $callable = $definition->getArgument(0);
+                $arguments = ['...'];
+
+                if ($callable instanceof Reference || $callable instanceof Definition) {
+                    $callable = [$callable, '__invoke'];
+                }
+            }
+
             if (\is_array($callable)) {
                 if (!preg_match('/^[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*$/', $callable[1])) {
                     throw new RuntimeException(sprintf('Cannot dump definition because of invalid factory method (%s).', $callable[1] ?: 'n/a'));
@@ -1159,7 +1168,7 @@ private function addNewInstance(Definition $definition, string $return = '', str
                 return $return.sprintf("[%s, '%s'](%s)", $class, $callable[1], $arguments ? implode(', ', $arguments) : '').$tail;
             }
 
-            if (str_starts_with($callable, '@=')) {
+            if (\is_string($callable) && str_starts_with($callable, '@=')) {
                 return $return.sprintf('(($args = %s) ? (%s) : null)',
                     $this->dumpValue(new ServiceLocatorArgument($definition->getArguments())),
                     $this->getExpressionLanguage()->compile(substr($callable, 2), ['this' => 'container', 'args' => 'args'])

Loader/Configurator/ContainerConfigurator.php

@@ -183,3 +183,13 @@ function service_closure(string $serviceId): ClosureReferenceConfigurator
 {
     return new ClosureReferenceConfigurator($serviceId);
 }
+
+/**
+ * Creates a closure.
+ */
+function closure(string|array|ReferenceConfigurator|Expression $callable): InlineServiceConfigurator
+{
+    return (new InlineServiceConfigurator(new Definition('Closure')))
+        ->factory(['Closure', 'fromCallable'])
+        ->args([$callable]);
+}

Loader/XmlFileLoader.php

@@ -495,7 +495,7 @@ private function getArgumentsAsPhp(\DOMElement $node, string $name, string $file
                 $invalidBehavior = ContainerInterface::NULL_ON_INVALID_REFERENCE;
             }
 
-            switch ($arg->getAttribute('type')) {
+            switch ($type = $arg->getAttribute('type')) {
                 case 'service':
                     if ('' === $arg->getAttribute('id')) {
                         throw new InvalidArgumentException(sprintf('Tag "<%s>" with type="service" has no or empty "id" attribute in "%s".', $name, $file));
@@ -517,13 +517,19 @@ private function getArgumentsAsPhp(\DOMElement $node, string $name, string $file
                     $arg = $this->getArgumentsAsPhp($arg, $name, $file);
                     $arguments[$key] = new IteratorArgument($arg);
                     break;
+                case 'closure':
                 case 'service_closure':
                     if ('' !== $arg->getAttribute('id')) {
                         $arg = new Reference($arg->getAttribute('id'), $invalidBehavior);
                     } else {
                         $arg = $this->getArgumentsAsPhp($arg, $name, $file);
                     }
-                    $arguments[$key] = new ServiceClosureArgument($arg);
+                    $arguments[$key] = match ($type) {
+                        'service_closure' => new ServiceClosureArgument($arg),
+                        'closure' => (new Definition('Closure'))
+                            ->setFactory(['Closure', 'fromCallable'])
+                            ->addArgument($arg),
+                    };
                     break;
                 case 'service_locator':
                     $arg = $this->getArgumentsAsPhp($arg, $name, $file);
@@ -532,7 +538,6 @@ private function getArgumentsAsPhp(\DOMElement $node, string $name, string $file
                 case 'tagged':
                 case 'tagged_iterator':
                 case 'tagged_locator':
-                    $type = $arg->getAttribute('type');
                     $forLocator = 'tagged_locator' === $type;
 
                     if (!$arg->getAttribute('tag')) {

Loader/YamlFileLoader.php

@@ -804,6 +804,14 @@ private function resolveServices(mixed $value, string $file, bool $isParameter =
     {
         if ($value instanceof TaggedValue) {
             $argument = $value->getValue();
+
+            if ('closure' === $value->getTag()) {
+                $argument = $this->resolveServices($argument, $file, $isParameter);
+
+                return (new Definition('Closure'))
+                    ->setFactory(['Closure', 'fromCallable'])
+                    ->addArgument($argument);
+            }
             if ('iterator' === $value->getTag()) {
                 if (!\is_array($argument)) {
                     throw new InvalidArgumentException(sprintf('"!iterator" tag only accepts sequences in "%s".', $file));

Loader/schema/dic/services/services-1.0.xsd

@@ -323,6 +323,7 @@
       <xsd:enumeration value="constant" />
       <xsd:enumeration value="binary" />
       <xsd:enumeration value="iterator" />
+      <xsd:enumeration value="closure" />
       <xsd:enumeration value="service_closure" />
       <xsd:enumeration value="service_locator" />
       <!-- "tagged" is an alias of "tagged_iterator", using "tagged_iterator" is preferred. -->

Tests/Dumper/PhpDumperTest.php

@@ -1534,6 +1534,20 @@ public function testExpressionInFactory()
 
         $this->assertSame(247, $container->get('foo')->bar);
     }
+
+    public function testClosure()
+    {
+        $container = new ContainerBuilder();
+        $container->register('closure', 'Closure')
+            ->setPublic('true')
+            ->setFactory(['Closure', 'fromCallable'])
+            ->setArguments([new Reference('bar')]);
+        $container->register('bar', 'stdClass');
+        $container->compile();
+        $dumper = new PhpDumper($container);
+
+        $this->assertStringEqualsFile(self::$fixturesPath.'/php/closure.php', $dumper->dump());
+    }
 }
 
 class Rot13EnvVarProcessor implements EnvVarProcessorInterface

Tests/Fixtures/config/closure.expected.yml

@@ -0,0 +1,10 @@
+
+services:
+    service_container:
+        class: Symfony\Component\DependencyInjection\ContainerInterface
+        public: true
+        synthetic: true
+    closure_property:
+        class: stdClass
+        public: true
+        properties: { foo: !service { class: Closure, arguments: [!service { class: stdClass }], factory: [Closure, fromCallable] } }

Tests/Fixtures/config/closure.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
+return new class() {
+    public function __invoke(ContainerConfigurator $c)
+    {
+        $c->services()
+            ->set('closure_property', 'stdClass')
+                ->public()
+                ->property('foo', closure(service('bar')))
+            ->set('bar', 'stdClass');
+    }
+};

Tests/Fixtures/php/closure.php

@@ -0,0 +1,55 @@
+<?php
+
+use Symfony\Component\DependencyInjection\Argument\RewindableGenerator;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\DependencyInjection\Container;
+use Symfony\Component\DependencyInjection\Exception\InvalidArgumentException;
+use Symfony\Component\DependencyInjection\Exception\LogicException;
+use Symfony\Component\DependencyInjection\Exception\RuntimeException;
+use Symfony\Component\DependencyInjection\ParameterBag\FrozenParameterBag;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
+
+/**
+ * @internal This class has been auto-generated by the Symfony Dependency Injection Component.
+ */
+class ProjectServiceContainer extends Container
+{
+    protected $parameters = [];
+
+    public function __construct()
+    {
+        $this->services = $this->privates = [];
+        $this->methodMap = [
+            'closure' => 'getClosureService',
+        ];
+
+        $this->aliases = [];
+    }
+
+    public function compile(): void
+    {
+        throw new LogicException('You cannot compile a dumped container that was already compiled.');
+    }
+
+    public function isCompiled(): bool
+    {
+        return true;
+    }
+
+    public function getRemovedIds(): array
+    {
+        return [
+            'bar' => true,
+        ];
+    }
+
+    /**
+     * Gets the public 'closure' shared service.
+     *
+     * @return \Closure
+     */
+    protected function getClosureService()
+    {
+        return $this->services['closure'] = (new \stdClass())->__invoke(...);
+    }
+}