Question

Do anyone know why this occurs?

as far I can get, the child class method is declared in the same way as parent’s.

Thanks!

here is my kernel code:

<?php

require_once __DIR__.'/../src/autoload.php';

use Symfony\Framework\Kernel;
use Symfony\Components\DependencyInjection\Loader\YamlFileLoader as ContainerLoader;
use Symfony\Components\Routing\Loader\YamlFileLoader as RoutingLoader;

use Symfony\Framework\KernelBundle;
use Symfony\Bundle\FrameworkBundle\FrameworkBundle;
use Symfony\Bundle\ZendBundle\ZendBundle;
use Symfony\Bundle\SwiftmailerBundle\SwiftmailerBundle;
use Symfony\Bundle\DoctrineBundle\DoctrineBundle;
use Symfony\Bundle\DoctrineMigrationsBundle\DoctrineMigrationsBundle;
use Symfony\Bundle\DoctrineMongoDBBundle\DoctrineMongoDBBundle;
use Symfony\Bundle\PropelBundle\PropelBundle;
use Symfony\Bundle\TwigBundle\TwigBundle;
use Application\UfaraBundle\UfaraBundle;



class UfaraKernel extends Kernel {
    public function registerRootDir() {
        return __DIR__;
    }

    public function registerBundles() {
        $bundles = array(
                new KernelBundle(),
                new FrameworkBundle(),
                new ZendBundle(),
                new SwiftmailerBundle(),
                new DoctrineBundle(),
                //new DoctrineMigrationsBundle(),
                //new DoctrineMongoDBBundle(),
                //new PropelBundle(),
                //new TwigBundle(),
                new UfaraBundle(),
        );

        if ($this->isDebug()) {
        }

        return $bundles;
    }

    public function registerBundleDirs() {
        $bundles = array(
                'Application'        => __DIR__.'/../src/Application',
                'Bundle'             => __DIR__.'/../src/Bundle',
                'Symfony\\Framework' => __DIR__.'/../src/vendor/symfony/src/Symfony/Framework',
                'Symfony\\Bundle'    => __DIR__.'/../src/vendor/symfony/src/Symfony/Bundle',
        );

        return $bundles;
    }

    public function registerContainerConfiguration(LoaderInterface $loader) {
        return $loader->load(__DIR__.'/config/config_'.$this->getEnvironment().'.yml');
    }

    public function registerRoutes() {
        $loader = new RoutingLoader($this->getBundleDirs());

        return $loader->load(__DIR__.'/config/routing.yml');
    }
}

here is the parent class code:

<?php

namespace Symfony\Framework;

use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Dumper\PhpDumper;
use Symfony\Component\DependencyInjection\Resource\FileResource;
use Symfony\Component\DependencyInjection\ParameterBag\ParameterBag;
use Symfony\Component\DependencyInjection\Loader\DelegatingLoader;
use Symfony\Component\DependencyInjection\Loader\LoaderResolver;
use Symfony\Component\DependencyInjection\Loader\LoaderInterface;
use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
use Symfony\Component\DependencyInjection\Loader\IniFileLoader;
use Symfony\Component\DependencyInjection\Loader\PhpFileLoader;
use Symfony\Component\DependencyInjection\Loader\ClosureLoader;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\HttpKernelInterface;
use Symfony\Framework\ClassCollectionLoader;

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <[e-mail]>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * The Kernel is the heart of the Symfony system. It manages an environment
 * that can host bundles.
 *
 * @author     Fabien Potencier <[e-mail]>
 */
abstract class Kernel implements HttpKernelInterface, \Serializable
{
    protected $bundles;
    protected $bundleDirs;
    protected $container;
    protected $rootDir;
    protected $environment;
    protected $debug;
    protected $booted;
    protected $name;
    protected $startTime;
    protected $request;

    const VERSION = '2.0.0-DEV';

    /**
     * Constructor.
     *
     * @param string  $environment The environment
     * @param Boolean $debug       Whether to enable debugging or not
     */
    public function __construct($environment, $debug)
    {
        $this->environment = $environment;
        $this->debug = (Boolean) $debug;
        $this->booted = false;
        $this->rootDir = realpath($this->registerRootDir());
        $this->name = basename($this->rootDir);

        if ($this->debug) {
            ini_set('display_errors', 1);
            error_reporting(-1);

            $this->startTime = microtime(true);
        } else {
            ini_set('display_errors', 0);
        }
    }

    public function __clone()
    {
        if ($this->debug) {
            $this->startTime = microtime(true);
        }

        $this->booted = false;
        $this->container = null;
        $this->request = null;
    }

    abstract public function registerRootDir();

    abstract public function registerBundles();

    abstract public function registerBundleDirs();

    abstract public function registerContainerConfiguration(LoaderInterface $loader);

    /**
     * Checks whether the current kernel has been booted or not.
     *
     * @return boolean $booted
     */
    public function isBooted()
    {
        return $this->booted;
    }

    /**
     * Boots the current kernel.
     *
     * This method boots the bundles, which MUST set
     * the DI container.
     *
     * @throws \LogicException When the Kernel is already booted
     */
    public function boot()
    {
        if (true === $this->booted) {
            throw new \LogicException('The kernel is already booted.');
        }

        if (!$this->isDebug()) {
            require_once __DIR__.'/bootstrap.php';
        }

        $this->bundles = $this->registerBundles();
        $this->bundleDirs = $this->registerBundleDirs();
        $this->container = $this->initializeContainer();

        // load core classes
        ClassCollectionLoader::load(
            $this->container->getParameter('kernel.compiled_classes'),
            $this->container->getParameter('kernel.cache_dir'),
            'classes',
            $this->container->getParameter('kernel.debug'),
            true
        );

        foreach ($this->bundles as $bundle) {
            $bundle->setContainer($this->container);
            $bundle->boot();
        }

        $this->booted = true;
    }

    /**
     * Shutdowns the kernel.
     *
     * This method is mainly useful when doing functional testing.
     */
    public function shutdown()
    {
        $this->booted = false;

        foreach ($this->bundles as $bundle) {
            $bundle->shutdown();
            $bundle->setContainer(null);
        }

        $this->container = null;
    }

    /**
     * Reboots the kernel.
     *
     * This method is mainly useful when doing functional testing.
     *
     * It is a shortcut for the call to shutdown() and boot().
     */
    public function reboot()
    {
        $this->shutdown();
        $this->boot();
    }

    /**
     * Gets the Request instance associated with the master request.
     *
     * @return Request A Request instance
     */
    public function getRequest()
    {
        return $this->request;
    }

    /**
     * Handles a request to convert it to a response by calling the HttpKernel service.
     *
     * @param  Request $request A Request instance
     * @param  integer $type    The type of the request (one of HttpKernelInterface::MASTER_REQUEST or HttpKernelInterface::SUB_REQUEST)
     * @param  Boolean $raw     Whether to catch exceptions or not
     *
     * @return Response $response A Response instance
     */
    public function handle(Request $request = null, $type = HttpKernelInterface::MASTER_REQUEST, $raw = false)
    {
        if (false === $this->booted) {
            $this->boot();
        }

        if (null === $request) {
            $request = $this->container->get('request');
        } else {
            $this->container->set('request', $request);
        }

        if (HttpKernelInterface::MASTER_REQUEST === $type) {
            $this->request = $request;
        }

        $response = $this->container->getHttpKernelService()->handle($request, $type, $raw);

        $this->container->set('request', $this->request);

        return $response;
    }

    /**
     * Gets the directories where bundles can be stored.
     *
     * @return array An array of directories where bundles can be stored
     */
    public function getBundleDirs()
    {
        return $this->bundleDirs;
    }

    /**
     * Gets the registered bundle names.
     *
     * @return array An array of registered bundle names
     */
    public function getBundles()
    {
        return $this->bundles;
    }

    /**
     * Checks if a given class name belongs to an active bundle.
     *
     * @param string $class A class name
     *
     * @return Boolean true if the class belongs to an active bundle, false otherwise
     */
    public function isClassInActiveBundle($class)
    {
        foreach ($this->bundles as $bundle) {
            $bundleClass = get_class($bundle);
            if (0 === strpos($class, substr($bundleClass, 0, strrpos($bundleClass, '\\')))) {
                return true;
            }
        }

        return false;
    }

    /**
     * Returns the Bundle name for a given class.
     *
     * @param string $class A class name
     *
     * @return string The Bundle name or null if the class does not belongs to a bundle
     */
    public function getBundleForClass($class)
    {
        $namespace = substr($class, 0, strrpos($class, '\\'));
        foreach (array_keys($this->getBundleDirs()) as $prefix) {
            if (0 === $pos = strpos($namespace, $prefix)) {
                return substr($namespace, strlen($prefix) + 1, strpos($class, 'Bundle\\') + 7);
            }
        }
    }

    public function getName()
    {
        return $this->name;
    }

    public function getSafeName()
    {
        return preg_replace('/[^a-zA-Z0-9_]+/', '', $this->name);
    }

    public function getEnvironment()
    {
        return $this->environment;
    }

    public function isDebug()
    {
        return $this->debug;
    }

    public function getRootDir()
    {
        return $this->rootDir;
    }

    public function getContainer()
    {
        return $this->container;
    }

    public function getStartTime()
    {
        return $this->debug ? $this->startTime : -INF;
    }

    public function getCacheDir()
    {
        return $this->rootDir.'/cache/'.$this->environment;
    }

    public function getLogDir()
    {
        return $this->rootDir.'/logs';
    }

    protected function initializeContainer()
    {
        $class = $this->getSafeName().ucfirst($this->environment).($this->debug ? 'Debug' : '').'ProjectContainer';
        $location = $this->getCacheDir().'/'.$class;
        $reload = $this->debug ? $this->needsReload($class, $location) : false;

        if ($reload || !file_exists($location.'.php')) {
            $this->buildContainer($class, $location.'.php');
        }

        require_once $location.'.php';

        $container = new $class();
        $container->set('kernel', $this);

        return $container;
    }

    public function getKernelParameters()
    {
        $bundles = array();
        foreach ($this->bundles as $bundle) {
            $bundles[] = get_class($bundle);
        }

        return array_merge(
            array(
                'kernel.root_dir'         => $this->rootDir,
                'kernel.environment'      => $this->environment,
                'kernel.debug'            => $this->debug,
                'kernel.name'             => $this->name,
                'kernel.cache_dir'        => $this->getCacheDir(),
                'kernel.logs_dir'         => $this->getLogDir(),
                'kernel.bundle_dirs'      => $this->bundleDirs,
                'kernel.bundles'          => $bundles,
                'kernel.charset'          => 'UTF-8',
                'kernel.compiled_classes' => array(),
            ),
            $this->getEnvParameters()
        );
    }

    protected function getEnvParameters()
    {
        $parameters = array();
        foreach ($_SERVER as $key => $value) {
            if ('SYMFONY__' === substr($key, 0, 9)) {
                $parameters[strtolower(str_replace('__', '.', substr($key, 9)))] = $value;
            }
        }

        return $parameters;
    }

    protected function needsReload($class, $location)
    {
        if (!file_exists($location.'.meta') || !file_exists($location.'.php')) {
            return true;
        }

        $meta = unserialize(file_get_contents($location.'.meta'));
        $time = filemtime($location.'.php');
        foreach ($meta as $resource) {
            if (!$resource->isUptodate($time)) {
                return true;
            }
        }

        return false;
    }

    protected function buildContainer($class, $file)
    {
        $parameterBag = new ParameterBag($this->getKernelParameters());

        $container = new ContainerBuilder($parameterBag);
        foreach ($this->bundles as $bundle) {
            $bundle->registerExtensions($container);

            if ($this->debug) {
                $container->addObjectResource($bundle);
            }
        }

        if (null !== $cont = $this->registerContainerConfiguration($this->getContainerLoader($container))) {
            $container->merge($cont);
        }
        $container->freeze();

        foreach (array('cache', 'logs') as $name) {
            $dir = $container->getParameter(sprintf('kernel.%s_dir', $name));
            if (!is_dir($dir)) {
                if (false === @mkdir($dir, 0777, true)) {
                    die(sprintf('Unable to create the %s directory (%s)', $name, dirname($dir)));
                }
            } elseif (!is_writable($dir)) {
                die(sprintf('Unable to write in the %s directory (%s)', $name, $dir));
            }
        }

        // cache the container
        $dumper = new PhpDumper($container);
        $content = $dumper->dump(array('class' => $class));
        if (!$this->debug) {
            $content = self::stripComments($content);
        }
        $this->writeCacheFile($file, $content);

        if ($this->debug) {
            $container->addObjectResource($this);

            // save the resources
            $this->writeCacheFile($this->getCacheDir().'/'.$class.'.meta', serialize($container->getResources()));
        }
    }

    protected function getContainerLoader(ContainerInterface $container)
    {
        $resolver = new LoaderResolver(array(
            new XmlFileLoader($container, $this->getBundleDirs()),
            new YamlFileLoader($container, $this->getBundleDirs()),
            new IniFileLoader($container, $this->getBundleDirs()),
            new PhpFileLoader($container, $this->getBundleDirs()),
            new ClosureLoader($container),
        ));

        return new DelegatingLoader($resolver);
    }

    /**
     * Removes comments from a PHP source string.
     *
     * We don't use the PHP php_strip_whitespace() function
     * as we want the content to be readable and well-formatted.
     *
     * @param string $source A PHP string
     *
     * @return string The PHP string with the comments removed
     */
    static public function stripComments($source)
    {
        if (!function_exists('token_get_all')) {
            return $source;
        }

        $output = '';
        foreach (token_get_all($source) as $token) {
            if (is_string($token)) {
                $output .= $token;
            } elseif (!in_array($token[0], array(T_COMMENT, T_DOC_COMMENT))) {
                $output .= $token[1];
            }
        }

        // replace multiple new lines with a single newline
        $output = preg_replace(array('/\s+$/Sm', '/\n+/S'), "\n", $output);

        // reformat {} "a la python"
        $output = preg_replace(array('/\n\s*\{/', '/\n\s*\}/'), array(' {', ' }'), $output);

        return $output;
    }

    protected function writeCacheFile($file, $content)
    {
        $tmpFile = tempnam(dirname($file), basename($file));
        if (false !== @file_put_contents($tmpFile, $content) && @rename($tmpFile, $file)) {
            chmod($file, 0644);

            return;
        }

        throw new \RuntimeException(sprintf('Failed to write cache file "%s".', $file));
    }

    public function serialize()
    {
        return serialize(array($this->environment, $this->debug));
    }

    public function unserialize($data)
    {
        list($environment, $debug) = unserialize($data);

        $this->__construct($environment, $debug);
    }
}

Answer 1

Your answer lies in the imported namespaces. In the Kernel‘s file, there’s this use clause:

use Symfony\Component\DependencyInjection\Loader\LoaderInterface;

So that ties LoaderInterface to the fully namespaced class Symfony\Component\DependencyInjection\Loader\LoaderInterface.

Basically making the signature:

public function registerContainerConfiguration(Symfony\Component\DependencyInjection\Loader\LoaderInterface $loader);

In your class, you don’t import that namespace. So PHP by default assumes the class is in your namespace (since none of the imported namespaces have that interface name).

So your signature is (since you don’t declare a namespace):

public function registerContainerConfiguration(\LoaderInterface $loader);

So to get them to match, simply add the use line to the top of your file:

use Symfony\Component\DependencyInjection\Loader\LoaderInterface;