Add ability to use container as a factory

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## 1.2.2 under development
 
+- Enh #354: Add ability to use container as a factory (@xepozz)
 - Enh #353: Add shortcut for tag reference #333 (@xepozz)
 
 ## 1.2.1 December 23, 2022

README.md

@@ -341,6 +341,41 @@ $config = ContainerConfig::create()
 $container = new Container($config);
 ```
 
+## Using the container as a factory
+
+You can use the container as a factory to create objects. 
+This is useful when you need to create an object every time from the bottom.
+
+```php
+use Yiisoft\Di\Container;
+use Yiisoft\Di\ContainerConfig;
+use Yiisoft\Di\Hook\AfterBuiltHook;
+
+$config = ContainerConfig::create()
+    ->withDefinitions([  
+        BlueCarService::class => [
+            'class' => BlueCarService::class,
+            'afterBuilt' => AfterBuiltHook::unsetInstance(), // it will be called after the object is created
+        ],
+    ]);
+
+$container = new Container($config);
+
+$container->get(BlueCarService::class) !== $container->get(BlueCarService::class); // true
+```
+
+You may use `afterBuilt` as you want. The value of the key must be a callable with the following signature:
+
+```php
+function (Container $container, string $id) {
+    /**
+     * @var $this Container
+     */
+    /** @psalm-scope-this Container */
+    unset($this->instances[$id]); // remove the instance from the container
+};
+```
+
 ## Resetting services state
 
 Despite stateful services isn't a great practice, these are often inevitable. When you build long-running

src/Container.php

@@ -35,7 +35,8 @@ final class Container implements ContainerInterface
 {
     private const META_TAGS = 'tags';
     private const META_RESET = 'reset';
-    private const ALLOWED_META = [self::META_TAGS, self::META_RESET];
+    private const META_AFTER_BUILT = 'afterBuilt';
+    private const ALLOWED_META = [self::META_TAGS, self::META_RESET, self::META_AFTER_BUILT];
 
     /**
      * @var DefinitionStorage Storage of object definitions.
@@ -67,6 +68,12 @@ final class Container implements ContainerInterface
      * @var Closure[]
      */
     private array $resetters = [];
+
+    /**
+     * @var Closure[]
+     */
+    public array $afterBuiltHooks = [];
+
     private bool $useResettersFromMeta = true;
 
     /**
@@ -134,10 +141,12 @@ public function has(string $id): bool
      */
     public function get(string $id)
     {
+        $result = null;
         if (!array_key_exists($id, $this->instances)) {
             try {
                 try {
-                    $this->instances[$id] = $this->build($id);
+                    /** @psalm-suppress MixedAssignment */
+                    $result = $this->instances[$id] = $this->build($id);
                 } catch (NotFoundExceptionInterface $e) {
                     if (!$this->delegates->has($id)) {
                         throw $e;
@@ -153,6 +162,7 @@ public function get(string $id)
                 throw new BuildingException($id, $e, $this->definitions->getBuildStack(), $e);
             }
         }
+        $this->callHookAfterBuilt($id);
 
         if ($id === StateResetter::class) {
             $delegatesResetter = null;
@@ -184,7 +194,7 @@ public function get(string $id)
         }
 
         /** @psalm-suppress MixedReturnStatement */
-        return $this->instances[$id];
+        return $result ?? $this->instances[$id];
     }
 
     /**
@@ -206,7 +216,7 @@ private function addDefinition(string $id, mixed $definition): void
             $this->validateMeta($meta);
         }
         /**
-         * @psalm-var array{reset?:Closure,tags?:string[]} $meta
+         * @psalm-var array{reset?:Closure,tags?:string[],afterBuilt?:Closure} $meta
          */
 
         if (isset($meta[self::META_TAGS])) {
@@ -215,6 +225,9 @@ private function addDefinition(string $id, mixed $definition): void
         if (isset($meta[self::META_RESET])) {
             $this->setDefinitionResetter($id, $meta[self::META_RESET]);
         }
+        if (isset($meta[self::META_AFTER_BUILT])) {
+            $this->setAfterBuiltHook($id, $meta[self::META_AFTER_BUILT]);
+        }
 
         unset($this->instances[$id]);
         $this->addDefinitionToStorage($id, $definition);
@@ -621,4 +634,16 @@ private function buildProvider(mixed $provider): ServiceProviderInterface
 
         return $providerInstance;
     }
+
+    private function callHookAfterBuilt(string $id): void
+    {
+        if (isset($this->afterBuiltHooks[$id])) {
+            $this->afterBuiltHooks[$id]->call($this, $this, $id);
+        }
+    }
+
+    private function setAfterBuiltHook(string $id, Closure $callback): void
+    {
+        $this->afterBuiltHooks[$id] = $callback;
+    }
 }

src/Hook/AfterBuiltHook.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Yiisoft\Di\Hook;
+
+use Closure;
+use Yiisoft\Di\Container;
+
+final class AfterBuiltHook
+{
+    public static function unsetInstance(): Closure
+    {
+        return function (Container $container, string $id) {
+            /**
+             * @var $this Container
+             */
+            /** @psalm-scope-this Container */
+            unset($this->instances[$id]);
+        };
+    }
+}

tests/Unit/Hook/AfterBuiltHookTest.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Unit\Hook;
+
+use PHPUnit\Framework\TestCase;
+use Yiisoft\Di\Container;
+use Yiisoft\Di\ContainerConfig;
+use Yiisoft\Di\Hook\AfterBuiltHook;
+use Yiisoft\Di\Tests\Support\EngineInterface;
+use Yiisoft\Di\Tests\Support\EngineMarkOne;
+
+final class AfterBuiltHookTest extends TestCase
+{
+    public function testDifferentObjects()
+    {
+        $config = ContainerConfig::create()
+            ->withDefinitions([
+                EngineInterface::class => [
+                    'class' => EngineMarkOne::class,
+                    'afterBuilt' => AfterBuiltHook::unsetInstance(),
+                ],
+            ]);
+        $container = new Container($config);
+
+        $this->assertNotSame(
+            $container->get(EngineInterface::class),
+            $container->get(EngineInterface::class),
+        );
+    }
+}