symfony · andrerom · Mar 15, 2015 · aramalipoor · Sep 6, 2015 · andrerom
diff --git a/src/Symfony/Component/HttpKernel/Bundle/BundleDependenciesInterface.php b/src/Symfony/Component/HttpKernel/Bundle/BundleDependenciesInterface.php
@@ -0,0 +1,91 @@
+<?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\HttpKernel\Bundle;
+
+/**
+ * Class BundleDependenciesInterface.
+ *
+ * Adds capability to let Bundles specify other bundles they need to load (before this one), both required and optional
+ * dependencies.
+ *
+ * This allows you to define only the bundle you want to use in registerBundles(), but don't need to take care about
+ * registering the dependencies it uses, and you won't need to make any changes in your kernel if those dependencies
+ * change.
+ *
+ * NOTE: In this interface bundle dependencies are returned as FQN strings because several bundles (and root) might
+ * register the same bundle. This means dependencies can not have arguments in its constructor, reflecting best practice
+ * in Symfony of not having any logic in Bundle constructors given it is executed on every Kernel boot.
+ *
+ * NOTE2: This functionality is not a bundle plugin system, but rather a way to set your upstream dependencies,
+ *        or in the case of a distribution bundle, all bundles they are to be used with.
+ *
+ * @author André Roemcke <andre.romcke@ez.no>
+ *
+ * @since 2.8
+ *
+ * @api
+ */
+interface BundleDependenciesInterface
+{
+    /**
+     * @const Flag a Bundle Dependency as required, if missing throw exception
+     *
+     * @link \Symfony\Component\HttpKernel\Exception\DependencyMismatchException
+     */
+    const DEP_REQUIRED = true;
+
+    /**
+     * @const Flag a Bundle Dependency as optional, if missing silently ignore it
+     */
+    const DEP_OPTIONAL = false;
+
+    /**
+     * Returns an array of bundle dependencies Kernel should register on boot.
+     *
+     * Dependencies will be registered before current bundle, implying current bundle *MUST* be loaded after as it
+     * for instance extends it.
+     *
+     * Example of use:
+     * ```php
+     * class AcmeBundle extends Bundle implements BundleDependenciesInterface
+     * {
+     *     public function getBundleDependencies($environment, $debug)
+     *     {
+     *         $dependencies = array();
+     *
+     *         // If you need to load some bundles only in dev using $environment (or in $debug)
+     *         if ($environment === 'dev') {
+     *              $dependencies['Egulias\SecurityDebugCommandBundle\EguliasSecurityDebugCommandBundle'] = self::DEP_REQUIRED;
+     *         }
+     *
+     *         return $dependencies + array(
+     *             // Keys must be Fully Qualified Name (FQN) for the class to avoid bundles being loaded several times
+     *             // Note: Currently, use of DEP_OPTIONAL causes a *uncached* file system call on boot (every request)
+     *             //       if dependency is missing, in a future versions this information might be cached.
+     *             'FOS\HttpCacheBundle\FOSHttpCacheBundle' => self::DEP_OPTIONAL,
+     *
+     *             // If you require PHP 5.5+ it is possible to use `::class` constant for required dependencies:
+     *             Oneup\FlysystemBundle\OneupFlysystemBundle::class => self::DEP_REQUIRED,
+     *         );
+     *     }
+     * }
+     * ```
+     *
+     * @param string $environment The current environment
+     * @param bool   $debug       Whether to debugging is enabled or not
+     *
+     * @return mixed[string] An array where key is bundle class (FQN) names as strings, and value DEP_* constants
+     *
+     * @api
+     */
+    public function getBundleDependencies($environment, $debug);
+}
diff --git a/src/Symfony/Component/HttpKernel/Exception/DependencyMismatchException.php b/src/Symfony/Component/HttpKernel/Exception/DependencyMismatchException.php
@@ -0,0 +1,40 @@
+<?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\HttpKernel\Exception;
+
+/**
+ * DependencyMismatchException.
+ *
+ * For exceptions related to dependency issues, like missing required dependency or recursive dependencies.
+ *
+ * @author André Roemcke <andre.romcke@ez.no>
+ *
+ * @since 2.8
+ */
+class DependencyMismatchException extends \RuntimeException
+{
+    /**
+     * Constructor.
+     *
+     * @param string     $msg      The message; for recursion issues, missing required dependency, ..
+     * @param array      $stack    The Bundle dependency stack trace up until the mismatch using bundle name or FQN
+     * @param \Exception $previous The previous exception if there was one
+     */
+    public function __construct($msg, array $stack, \Exception $previous = null)
+    {
+        parent::__construct(
+            sprintf("%s, bundle dependencies stack trace: '%s'", $msg, var_export($stack, true)),
+            0,
+            $previous
+        );
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/Kernel.php b/src/Symfony/Component/HttpKernel/Kernel.php
@@ -27,10 +27,12 @@
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Bundle\BundleInterface;
+use Symfony\Component\HttpKernel\Bundle\BundleDependenciesInterface;
 use Symfony\Component\HttpKernel\Config\EnvParametersResource;
 use Symfony\Component\HttpKernel\Config\FileLocator;
 use Symfony\Component\HttpKernel\DependencyInjection\MergeExtensionConfigurationPass;
 use Symfony\Component\HttpKernel\DependencyInjection\AddClassesToCachePass;
+use Symfony\Component\HttpKernel\Exception\DependencyMismatchException;
 use Symfony\Component\Config\Loader\LoaderResolver;
 use Symfony\Component\Config\Loader\DelegatingLoader;
 use Symfony\Component\Config\ConfigCache;
@@ -468,7 +470,7 @@ protected function initializeBundles()
         $topMostBundles = array();
         $directChildren = array();
 
-        foreach ($this->registerBundles() as $bundle) {
+        foreach ($this->registeredDependencies() as $bundle) {
             $name = $bundle->getName();
             if (isset($this->bundles[$name])) {
                 throw new \LogicException(sprintf('Trying to register two bundles with the same name "%s"', $name));
@@ -514,6 +516,100 @@ protected function initializeBundles()
         }
     }
 
+    /**
+     * Returns an array of bundles to register, with dependencies, ordered.
+     *
+     * @uses appendDependenciesRecursively
+     *
+     * @return BundleInterface[] An array of bundle instances.
+     */
+    protected function registeredDependencies()
+    {
+        $bundles = $this->registerBundles();
+        $children = $rootBundles = array();
+        $hasDependencies = false;
+
+        // Build up bundles as a hash with FQN for basis to rebuild again in correct order given dependencies
+        foreach ($bundles as $bundle) {
+            $bundleFQN = get_class($bundle);
+            $children[$bundleFQN] = BundleDependenciesInterface::DEP_REQUIRED;
+            $rootBundles[$bundleFQN] = $bundle;
+
+            if ($bundle instanceof BundleDependenciesInterface) {
+                $hasDependencies = true;
+            }
+        }
+
+        if (!$hasDependencies) {
+            return $bundles;
+        }
+
+        // Rebuild bundles order with dependencies recursively
+        $bundles = array();
+        $stack = array(get_class($this) => true);
+        $this->appendDependenciesRecursively(
+            $children,
+            $bundles,
+            $rootBundles,
+            $stack
+       );
+
+        return $bundles;
+    }
+
+    /**
+     * Append dependencies of bundles recursively.
+     *
+     * Accepted arguments are as documented below where `string` implies a string with class FQN(Fully Qualified Name),
+     * this string must be in exactly same format as returned by get_class() and PHP 5.5's CLASS constant.
+     * Example of FQN string: "Symfony\Component\HttpKernel\Bundle\BundleInterface"
+     *
+     * @link BundleDependenciesInterface For further details on dependencies and DEP_* constants.
+     *
+     * @param mixed[string]           $children    Dependencies to apply, key FQN, value {@see BundleDependenciesInterface} constants
+     * @param BundleInterface[string] $bundles     Ordered bundles to append dependencies to
+     * @param BundleInterface[string] $rootBundles Loaded Bundles from registerRootBundles()
+     * @param bool[string]            $stack       For recursion protection, and for debug use on exceptions
+     *
+     * @throws \Symfony\Component\HttpKernel\Exception\DependencyMismatchException On missing dependencies
+     */
+    protected function appendDependenciesRecursively(array $children, array &$bundles, array $rootBundles, array $stack)
+    {
+        foreach ($children as $dependencyFQN => $requiredFlag) {
+            if (isset($bundles[$dependencyFQN])) {
+                continue;
+            } elseif (isset($stack[$dependencyFQN])) {
+                throw new DependencyMismatchException(sprintf('Recursive dependency for "%s"', $dependencyFQN), array_keys($stack));
+            }
+
+            // If already loaded root bundle, use that to not re instantiate
+            if (isset($rootBundles[$dependencyFQN])) {
+                $dependency = $rootBundles[$dependencyFQN];
+            } else {
+                if (!class_exists($dependencyFQN)) {
+                    if ($requiredFlag === BundleDependenciesInterface::DEP_OPTIONAL) {
+                        continue;
+                    }
+                    throw new DependencyMismatchException(sprintf('Could not find "%s"', $dependencyFQN), array_keys($stack));
+                }
+                $dependency = new $dependencyFQN();
+            }
+
+            // Append dependencies of the dependency before we append dependency itself
+            if ($dependency instanceof BundleDependenciesInterface) {
+                $stack[$dependencyFQN] = true;
+                $this->appendDependenciesRecursively(
+                    $dependency->getBundleDependencies($this->environment, $this->debug),
+                    $bundles,
+                    $rootBundles,
+                    $stack
+               );
+            }
+
+            $bundles[$dependencyFQN] = $dependency;
+        }
+    }
+
     /**
      * Gets the container class.
      *

diff --git a/...Symfony/Component/HttpKernel/Tests/Fixtures/BundleDependencies/BundleADependenciesNon.php b/...Symfony/Component/HttpKernel/Tests/Fixtures/BundleDependencies/BundleADependenciesNon.php
@@ -0,0 +1,22 @@
+<?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\HttpKernel\Tests\Fixtures\BundleDependencies;
+
+use Symfony\Component\HttpKernel\Bundle\BundleDependenciesInterface;
+
+class BundleADependenciesNon implements BundleDependenciesInterface
+{
+    public function getBundleDependencies($environment, $debug)
+    {
+        return array();
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleDependencies/BundleBDependenciesA.php b/src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleDependencies/BundleBDependenciesA.php
@@ -0,0 +1,22 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpKernel\Tests\Fixtures\BundleDependencies;
+
+use Symfony\Component\HttpKernel\Bundle\BundleDependenciesInterface;
+
+class BundleBDependenciesA implements BundleDependenciesInterface
+{
+    public function getBundleDependencies($environment, $debug)
+    {
+        return array('Symfony\Component\HttpKernel\Tests\Fixtures\BundleDependencies\BundleADependenciesNon' => self::DEP_REQUIRED);
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleDependencies/BundleCDependenciesBA.php b/src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleDependencies/BundleCDependenciesBA.php
@@ -0,0 +1,31 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpKernel\Tests\Fixtures\BundleDependencies;
+
+use Symfony\Component\HttpKernel\Bundle\BundleDependenciesInterface;
+
+class BundleCDependenciesBA implements BundleDependenciesInterface
+{
+    public function getBundleDependencies($environment, $debug)
+    {
+        if ('prod_test' === $environment) {
+            return array();
+        } elseif ($debug) {
+            return array('Symfony\Component\HttpKernel\Tests\Fixtures\BundleDependencies\BundleADependenciesNon' => self::DEP_REQUIRED);
+        }
+
+        return array(
+            'Symfony\Component\HttpKernel\Tests\Fixtures\BundleDependencies\BundleBDependenciesA' => self::DEP_REQUIRED,
+            'Symfony\Component\HttpKernel\Tests\Fixtures\BundleDependencies\BundleADependenciesNon' => self::DEP_OPTIONAL,
+        );
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleDependencies/BundleDDependenciesE.php b/src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleDependencies/BundleDDependenciesE.php
@@ -0,0 +1,22 @@
+<?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\HttpKernel\Tests\Fixtures\BundleDependencies;
+
+use Symfony\Component\HttpKernel\Bundle\BundleDependenciesInterface;
+
+class BundleDDependenciesE implements BundleDependenciesInterface
+{
+    public function getBundleDependencies($environment, $debug)
+    {
+        return array('Symfony\Component\HttpKernel\Tests\Fixtures\BundleDependencies\BundleEDependenciesD' => self::DEP_REQUIRED);
+    }
+}
diff --git a/src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleDependencies/BundleEDependenciesD.php b/src/Symfony/Component/HttpKernel/Tests/Fixtures/BundleDependencies/BundleEDependenciesD.php
@@ -0,0 +1,22 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpKernel\Tests\Fixtures\BundleDependencies;
+
+use Symfony\Component\HttpKernel\Bundle\BundleDependenciesInterface;
+
+class BundleEDependenciesD implements BundleDependenciesInterface
+{
+    public function getBundleDependencies($environment, $debug)
+    {
+        return array('Symfony\Component\HttpKernel\Tests\Fixtures\BundleDependencies\BundleDDependenciesE' => self::DEP_REQUIRED);
+    }
+}