Merge remote-tracking branch 'MyIgel/templating'

20 files changed, 711 insertions, 20 deletions

diff --git a/src/Application.php b/src/Application.php
index 6644a6cf..86397a2c 100644
--- a/src/Application.php
+++ b/src/Application.php
@@ -107,6 +107,7 @@ class Application extends Container
         $this->instance('path', $appPath);
         $this->instance('path.config', $appPath . DIRECTORY_SEPARATOR . 'config');
         $this->instance('path.lang', $appPath . DIRECTORY_SEPARATOR . 'locale');
+        $this->instance('path.views', $appPath . DIRECTORY_SEPARATOR . 'templates');
     }
 
     /**
diff --git a/src/Config/ConfigServiceProvider.php b/src/Config/ConfigServiceProvider.php
index 9fbccd68..63f43ced 100644
--- a/src/Config/ConfigServiceProvider.php
+++ b/src/Config/ConfigServiceProvider.php
@@ -13,6 +13,7 @@ class ConfigServiceProvider extends ServiceProvider
     public function register()
     {
         $config = $this->app->make(Config::class);
+        $this->app->instance(Config::class, $config);
         $this->app->instance('config', $config);
 
         foreach ($this->configFiles as $file) {
diff --git a/src/Helpers/TranslationServiceProvider.php b/src/Helpers/TranslationServiceProvider.php
new file mode 100644
index 00000000..9d86df7d
--- /dev/null
+++ b/src/Helpers/TranslationServiceProvider.php
@@ -0,0 +1,58 @@
+<?php
+
+namespace Engelsystem\Helpers;
+
+use Engelsystem\Config\Config;
+use Engelsystem\Container\ServiceProvider;
+use Symfony\Component\HttpFoundation\Session\Session;
+
+class TranslationServiceProvider extends ServiceProvider
+{
+    public function register()
+    {
+        /** @var Config $config */
+        $config = $this->app->get('config');
+        /** @var Session $session */
+        $session = $this->app->get('session');
+
+        $locales = $config->get('locales');
+        $locale = $config->get('default_locale');
+
+        $sessionLocale = $session->get('locale', $locale);
+        if (isset($locales[$sessionLocale])) {
+            $locale = $sessionLocale;
+        }
+
+        $this->initGettext();
+        $session->set('locale', $locale);
+
+        $translator = $this->app->make(
+            Translator::class,
+            ['locale' => $locale, 'locales' => $locales, 'localeChangeCallback' => [$this, 'setLocale']]
+        );
+        $this->app->instance(Translator::class, $translator);
+        $this->app->instance('translator', $translator);
+    }
+
+    /**
+     * @param string $textDomain
+     * @param string $encoding
+     * @codeCoverageIgnore
+     */
+    protected function initGettext($textDomain = 'default', $encoding = 'UTF-8')
+    {
+        bindtextdomain($textDomain, $this->app->get('path.lang'));
+        bind_textdomain_codeset($textDomain, $encoding);
+        textdomain($textDomain);
+    }
+
+    /**
+     * @param string $locale
+     * @codeCoverageIgnore
+     */
+    public function setLocale($locale)
+    {
+        putenv('LC_ALL=' . $locale);
+        setlocale(LC_ALL, $locale);
+    }
+}
diff --git a/src/Helpers/Translator.php b/src/Helpers/Translator.php
new file mode 100644
index 00000000..1e953a21
--- /dev/null
+++ b/src/Helpers/Translator.php
@@ -0,0 +1,105 @@
+<?php
+
+namespace Engelsystem\Helpers;
+
+class Translator
+{
+    /** @var string[] */
+    protected $locales;
+
+    /** @var string */
+    protected $locale;
+
+    /** @var callable */
+    protected $localeChangeCallback;
+
+    /**
+     * Translator constructor.
+     *
+     * @param string   $locale
+     * @param string[] $locales
+     * @param callable $localeChangeCallback
+     */
+    public function __construct(string $locale, array $locales = [], callable $localeChangeCallback = null)
+    {
+        $this->localeChangeCallback = $localeChangeCallback;
+
+        $this->setLocale($locale);
+        $this->setLocales($locales);
+    }
+
+    /**
+     * Get the translation for a given key
+     *
+     * @param string $key
+     * @param array  $replace
+     * @return string
+     */
+    public function translate(string $key, array $replace = []): string
+    {
+        $translated = $this->translateGettext($key);
+
+        if (!empty($replace)) {
+            $translated = call_user_func_array('sprintf', array_merge([$translated], $replace));
+        }
+
+        return $translated;
+    }
+
+    /**
+     * Translate the key via gettext
+     *
+     * @param string $key
+     * @return string
+     * @codeCoverageIgnore
+     */
+    protected function translateGettext(string $key): string
+    {
+        return _($key);
+    }
+
+    /**
+     * @return string
+     */
+    public function getLocale(): string
+    {
+        return $this->locale;
+    }
+
+    /**
+     * @param string $locale
+     */
+    public function setLocale(string $locale)
+    {
+        $this->locale = $locale;
+
+        if (is_callable($this->localeChangeCallback)) {
+            call_user_func_array($this->localeChangeCallback, [$locale]);
+        }
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getLocales(): array
+    {
+        return $this->locales;
+    }
+
+    /**
+     * @param string $locale
+     * @return bool
+     */
+    public function hasLocale(string $locale): bool
+    {
+        return isset($this->locales[$locale]);
+    }
+
+    /**
+     * @param string[] $locales
+     */
+    public function setLocales(array $locales)
+    {
+        $this->locales = $locales;
+    }
+}
diff --git a/src/Http/Response.php b/src/Http/Response.php
index 9db6fa83..d79ab98b 100644
--- a/src/Http/Response.php
+++ b/src/Http/Response.php
@@ -2,6 +2,7 @@
 
 namespace Engelsystem\Http;
 
+use Engelsystem\Renderer\Renderer;
 use Psr\Http\Message\ResponseInterface;
 use Symfony\Component\HttpFoundation\Response as SymfonyResponse;
 
@@ -9,6 +10,25 @@ class Response extends SymfonyResponse implements ResponseInterface
 {
     use MessageTrait;
 
+    /** @var Renderer */
+    protected $view;
+
+    /**
+     * @param string   $content
+     * @param int      $status
+     * @param array    $headers
+     * @param Renderer $view
+     */
+    public function __construct(
+        $content = '',
+        int $status = 200,
+        array $headers = array(),
+        Renderer $view = null
+    ) {
+        $this->view = $view;
+        parent::__construct($content, $status, $headers);
+    }
+
     /**
      * Return an instance with the specified status code and, optionally, reason phrase.
      *
@@ -72,4 +92,25 @@ class Response extends SymfonyResponse implements ResponseInterface
 
         return $new;
     }
+
+    /**
+     * Return an instance with the rendered content.
+     *
+     * THis method retains the immutability of the message and returns
+     * an instance with the updated status and headers
+     *
+     * @param string              $view
+     * @param array               $data
+     * @param int                 $status
+     * @param string[]|string[][] $headers
+     * @return Response
+     */
+    public function withView($view, $data = [], $status = 200, $headers = [])
+    {
+        if (!$this->view instanceof Renderer) {
+            throw new \InvalidArgumentException('Renderer not defined');
+        }
+
+        return $this->create($this->view->render($view, $data), $status, $headers);
+    }
 }
diff --git a/src/Http/SessionServiceProvider.php b/src/Http/SessionServiceProvider.php
index 55e3f48b..59121a3b 100644
--- a/src/Http/SessionServiceProvider.php
+++ b/src/Http/SessionServiceProvider.php
@@ -17,6 +17,7 @@ class SessionServiceProvider extends ServiceProvider
         $this->app->bind(SessionStorageInterface::class, 'session.storage');
 
         $session = $this->app->make(Session::class);
+        $this->app->instance(Session::class, $session);
         $this->app->instance('session', $session);
 
         /** @var Request $request */
diff --git a/src/Http/UrlGeneratorServiceProvider.php b/src/Http/UrlGeneratorServiceProvider.php
index 37304076..9b9988aa 100644
--- a/src/Http/UrlGeneratorServiceProvider.php
+++ b/src/Http/UrlGeneratorServiceProvider.php
@@ -9,6 +9,7 @@ class UrlGeneratorServiceProvider extends ServiceProvider
     public function register()
     {
         $urlGenerator = $this->app->make(UrlGenerator::class);
+        $this->app->instance(UrlGenerator::class, $urlGenerator);
         $this->app->instance('http.urlGenerator', $urlGenerator);
     }
 }
diff --git a/src/Middleware/ErrorHandler.php b/src/Middleware/ErrorHandler.php
new file mode 100644
index 00000000..a7c4cfe6
--- /dev/null
+++ b/src/Middleware/ErrorHandler.php
@@ -0,0 +1,80 @@
+<?php
+
+namespace Engelsystem\Middleware;
+
+use Engelsystem\Http\Response;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+use Twig_LoaderInterface as TwigLoader;
+
+class ErrorHandler implements MiddlewareInterface
+{
+    /** @var TwigLoader */
+    protected $loader;
+
+    /** @var string */
+    protected $viewPrefix = 'errors/';
+
+    /**
+     * @param TwigLoader $loader
+     */
+    public function __construct(TwigLoader $loader)
+    {
+        $this->loader = $loader;
+    }
+
+    /**
+     * Handles any error messages
+     *
+     * Should be added at the beginning
+     *
+     * @param ServerRequestInterface  $request
+     * @param RequestHandlerInterface $handler
+     * @return ResponseInterface
+     */
+    public function process(
+        ServerRequestInterface $request,
+        RequestHandlerInterface $handler
+    ): ResponseInterface {
+        $response = $handler->handle($request);
+
+        $statusCode = $response->getStatusCode();
+        if ($statusCode < 400 || !$response instanceof Response) {
+            return $response;
+        }
+
+        $view = $this->selectView($statusCode);
+
+        return $response->withView(
+            $this->viewPrefix . $view,
+            [
+                'status'  => $statusCode,
+                'content' => $response->getContent(),
+            ],
+            $statusCode,
+            $response->getHeaders()
+        );
+    }
+
+    /**
+     * Select a view based on the given status code
+     *
+     * @param int $statusCode
+     * @return string
+     */
+    protected function selectView(int $statusCode): string
+    {
+        $hundreds = intdiv($statusCode, 100);
+
+        $viewsList = [$statusCode, $hundreds, $hundreds * 100];
+        foreach ($viewsList as $view) {
+            if ($this->loader->exists($this->viewPrefix . $view)) {
+                return $view;
+            }
+        }
+
+        return 'default';
+    }
+}
diff --git a/src/Middleware/LegacyMiddleware.php b/src/Middleware/LegacyMiddleware.php
index 276fb3ee..78132815 100644
--- a/src/Middleware/LegacyMiddleware.php
+++ b/src/Middleware/LegacyMiddleware.php
@@ -83,7 +83,7 @@ class LegacyMiddleware implements MiddlewareInterface
         }
 
         if (empty($title) and empty($content)) {
-            $page = '404';
+            $page = 404;
             $title = _('Page not found');
             $content = _('This page could not be found or you don\'t have permission to view it. You probably have to sign in or register in order to gain access!');
         }
@@ -277,29 +277,17 @@ class LegacyMiddleware implements MiddlewareInterface
             $parameters['meetings'] = 1;
         }
 
-        $status = 200;
-        if ($page == '404') {
-            $status = 404;
-            $content = info($content, true);
+        if (!empty($page) && is_int($page)) {
+            return response($content, (int)$page);
         }
 
-        return response(view(__DIR__ . '/../../templates/layout.html', [
-            'theme'          => isset($user) ? $user['color'] : config('theme'),
+        return response(view('layouts/app', [
             'title'          => $title,
-            'atom_link'      => ($page == 'news' || $page == 'user_meetings')
-                ? ' <link href="'
-                . page_link_to('atom', $parameters)
-                . '" type = "application/atom+xml" rel = "alternate" title = "Atom Feed">'
-                : '',
-            'start_page_url' => page_link_to('/'),
-            'credits_url'    => page_link_to('credits'),
+            'atom_feed'      => ($page == 'news' || $page == 'user_meetings') ? $parameters : [],
             'menu'           => make_menu(),
             'content'        => msg() . $content,
             'header_toolbar' => header_toolbar(),
-            'faq_url'        => config('faq_url'),
-            'contact_email'  => config('contact_email'),
-            'locale'         => locale(),
             'event_info'     => EventConfig_info($event_config) . ' <br />'
-        ]), $status);
+        ]), 200);
     }
 }
diff --git a/src/Middleware/SetLocale.php b/src/Middleware/SetLocale.php
new file mode 100644
index 00000000..86fa0b7f
--- /dev/null
+++ b/src/Middleware/SetLocale.php
@@ -0,0 +1,49 @@
+<?php
+
+namespace Engelsystem\Middleware;
+
+use Engelsystem\Helpers\Translator;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+use Symfony\Component\HttpFoundation\Session\Session;
+
+class SetLocale implements MiddlewareInterface
+{
+    /** @var Translator */
+    protected $translator;
+
+    /** @var Session */
+    protected $session;
+
+    /**
+     * @param Translator $translator
+     * @param Session    $session
+     */
+    public function __construct(Translator $translator, Session $session)
+    {
+        $this->translator = $translator;
+        $this->session = $session;
+    }
+
+    /**
+     * Process an incoming server request and setting the locale if required
+     *
+     * @param ServerRequestInterface  $request
+     * @param RequestHandlerInterface $handler
+     * @return ResponseInterface
+     */
+    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
+    {
+        $query = $request->getQueryParams();
+        if (isset($query['set-locale']) && $this->translator->hasLocale($query['set-locale'])) {
+            $locale = $query['set-locale'];
+
+            $this->translator->setLocale($locale);
+            $this->session->set('locale', $locale);
+        }
+
+        return $handler->handle($request);
+    }
+}
diff --git a/src/Renderer/RendererServiceProvider.php b/src/Renderer/RendererServiceProvider.php
index 3e8d69bc..2e41837b 100644
--- a/src/Renderer/RendererServiceProvider.php
+++ b/src/Renderer/RendererServiceProvider.php
@@ -24,12 +24,14 @@ class RendererServiceProvider extends ServiceProvider
     protected function registerRenderer()
     {
         $renderer = $this->app->make(Renderer::class);
+        $this->app->instance(Renderer::class, $renderer);
         $this->app->instance('renderer', $renderer);
     }
 
     protected function registerHtmlEngine()
     {
         $htmlEngine = $this->app->make(HtmlEngine::class);
+        $this->app->instance(HtmlEngine::class, $htmlEngine);
         $this->app->instance('renderer.htmlEngine', $htmlEngine);
         $this->app->tag('renderer.htmlEngine', ['renderer.engine']);
     }
diff --git a/src/Renderer/Twig/Extensions/Config.php b/src/Renderer/Twig/Extensions/Config.php
new file mode 100644
index 00000000..dbbe93e7
--- /dev/null
+++ b/src/Renderer/Twig/Extensions/Config.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Engelsystem\Renderer\Twig\Extensions;
+
+use Engelsystem\Config\Config as EngelsystemConfig;
+use Twig_Extension as TwigExtension;
+use Twig_Function as TwigFunction;
+
+class Config extends TwigExtension
+{
+    /** @var EngelsystemConfig */
+    protected $config;
+
+    /**
+     * @param EngelsystemConfig $config
+     */
+    public function __construct(EngelsystemConfig $config)
+    {
+        $this->config = $config;
+    }
+
+    /**
+     * @return TwigFunction[]
+     */
+    public function getFunctions()
+    {
+        return [
+            new TwigFunction('config', [$this->config, 'get']),
+        ];
+    }
+}
diff --git a/src/Renderer/Twig/Extensions/Globals.php b/src/Renderer/Twig/Extensions/Globals.php
new file mode 100644
index 00000000..f9bffbc8
--- /dev/null
+++ b/src/Renderer/Twig/Extensions/Globals.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Engelsystem\Renderer\Twig\Extensions;
+
+use Twig_Extension as TwigExtension;
+use Twig_Extension_GlobalsInterface as GlobalsInterface;
+
+class Globals extends TwigExtension implements GlobalsInterface
+{
+    /**
+     * Returns a list of global variables to add to the existing list.
+     *
+     * @return array An array of global variables
+     */
+    public function getGlobals()
+    {
+        global $user;
+
+        return [
+            'user' => isset($user) ? $user : [],
+        ];
+    }
+}
diff --git a/src/Renderer/Twig/Extensions/Session.php b/src/Renderer/Twig/Extensions/Session.php
new file mode 100644
index 00000000..4690f701
--- /dev/null
+++ b/src/Renderer/Twig/Extensions/Session.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Engelsystem\Renderer\Twig\Extensions;
+
+use Symfony\Component\HttpFoundation\Session\Session as SymfonySession;
+use Twig_Extension as TwigExtension;
+use Twig_Function as TwigFunction;
+
+class Session extends TwigExtension
+{
+    /** @var SymfonySession */
+    protected $session;
+
+    /**
+     * @param SymfonySession $session
+     */
+    public function __construct(SymfonySession $session)
+    {
+        $this->session = $session;
+    }
+
+    /**
+     * @return TwigFunction[]
+     */
+    public function getFunctions()
+    {
+        return [
+            new TwigFunction('session_get', [$this->session, 'get']),
+        ];
+    }
+}
diff --git a/src/Renderer/Twig/Extensions/Translation.php b/src/Renderer/Twig/Extensions/Translation.php
new file mode 100644
index 00000000..63f9800e
--- /dev/null
+++ b/src/Renderer/Twig/Extensions/Translation.php
@@ -0,0 +1,57 @@
+<?php
+
+namespace Engelsystem\Renderer\Twig\Extensions;
+
+use Engelsystem\Helpers\Translator;
+use Twig_Extension as TwigExtension;
+use Twig_Extensions_TokenParser_Trans as TranslationTokenParser;
+use Twig_Filter as TwigFilter;
+use Twig_Function as TwigFunction;
+use Twig_TokenParserInterface as TwigTokenParser;
+
+class Translation extends TwigExtension
+{
+    /** @var Translator */
+    protected $translator;
+
+    /** @var TranslationTokenParser */
+    protected $tokenParser;
+
+    /**
+     * @param Translator             $translator
+     * @param TranslationTokenParser $tokenParser
+     */
+    public function __construct(Translator $translator, TranslationTokenParser $tokenParser)
+    {
+        $this->translator = $translator;
+        $this->tokenParser = $tokenParser;
+    }
+
+    /**
+     * @return array
+     */
+    public function getFilters()
+    {
+        return [
+            new TwigFilter('trans', [$this->translator, 'translate']),
+        ];
+    }
+
+    /**
+     * @return TwigFunction[]
+     */
+    public function getFunctions()
+    {
+        return [
+            new TwigFunction('__', [$this->translator, 'translate']),
+        ];
+    }
+
+    /**
+     * @return TwigTokenParser[]
+     */
+    public function getTokenParsers()
+    {
+        return [$this->tokenParser];
+    }
+}
diff --git a/src/Renderer/Twig/Extensions/Url.php b/src/Renderer/Twig/Extensions/Url.php
new file mode 100644
index 00000000..62e59782
--- /dev/null
+++ b/src/Renderer/Twig/Extensions/Url.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace Engelsystem\Renderer\Twig\Extensions;
+
+use Engelsystem\Http\UrlGenerator;
+use Twig_Extension as TwigExtension;
+use Twig_Function as TwigFunction;
+
+class Url extends TwigExtension
+{
+    /** @var UrlGenerator */
+    protected $urlGenerator;
+
+    /**
+     * @param UrlGenerator $urlGenerator
+     */
+    public function __construct(UrlGenerator $urlGenerator)
+    {
+        $this->urlGenerator = $urlGenerator;
+    }
+
+    /**
+     * @return TwigFunction[]
+     */
+    public function getFunctions()
+    {
+        return [
+            new TwigFunction('url', [$this, 'getUrl']),
+        ];
+    }
+
+    /**
+     * @param string $path
+     * @param array  $parameters
+     * @return UrlGenerator|string
+     */
+    public function getUrl($path, $parameters = [])
+    {
+        $path = str_replace('_', '-', $path);
+
+        return $this->urlGenerator->to($path, $parameters);
+    }
+}
diff --git a/src/Renderer/TwigEngine.php b/src/Renderer/TwigEngine.php
new file mode 100644
index 00000000..55a2e299
--- /dev/null
+++ b/src/Renderer/TwigEngine.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace Engelsystem\Renderer;
+
+use Twig_Environment as Twig;
+use Twig_Error_Loader as LoaderError;
+use Twig_Error_Runtime as RuntimeError;
+use Twig_Error_Syntax as SyntaxError;
+
+class TwigEngine implements EngineInterface
+{
+    /** @var Twig */
+    protected $twig;
+
+    public function __construct(Twig $twig)
+    {
+        $this->twig = $twig;
+    }
+
+    /**
+     * Render a twig template
+     *
+     * @param string $path
+     * @param array  $data
+     * @return string
+     * @throws LoaderError|RuntimeError|SyntaxError
+     */
+    public function get($path, $data = [])
+    {
+        return $this->twig->render($path, $data);
+    }
+
+    /**
+     * @param string $path
+     * @return bool
+     */
+    public function canRender($path)
+    {
+        return $this->twig->getLoader()->exists($path);
+    }
+}
diff --git a/src/Renderer/TwigLoader.php b/src/Renderer/TwigLoader.php
new file mode 100644
index 00000000..154e6dbb
--- /dev/null
+++ b/src/Renderer/TwigLoader.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace Engelsystem\Renderer;
+
+use Twig_Error_Loader;
+use Twig_Loader_Filesystem as FilesystemLoader;
+
+class TwigLoader extends FilesystemLoader
+{
+    /**
+     * @param string $name
+     * @param bool   $throw
+     * @return false|string
+     * @throws Twig_Error_Loader
+     */
+    public function findTemplate($name, $throw = true)
+    {
+        $extension = '.twig';
+        $extensionLength = strlen($extension);
+        if (substr($name, -$extensionLength, $extensionLength) !== $extension) {
+            $name .= $extension;
+        }
+
+        return parent::findTemplate($name, $throw);
+    }
+}
diff --git a/src/Renderer/TwigServiceProvider.php b/src/Renderer/TwigServiceProvider.php
new file mode 100644
index 00000000..0f453989
--- /dev/null
+++ b/src/Renderer/TwigServiceProvider.php
@@ -0,0 +1,77 @@
+<?php
+
+namespace Engelsystem\Renderer;
+
+use Engelsystem\Container\ServiceProvider;
+use Engelsystem\Renderer\Twig\Extensions\Config;
+use Engelsystem\Renderer\Twig\Extensions\Globals;
+use Engelsystem\Renderer\Twig\Extensions\Session;
+use Engelsystem\Renderer\Twig\Extensions\Translation;
+use Engelsystem\Renderer\Twig\Extensions\Url;
+use Twig_Environment as Twig;
+use Twig_LoaderInterface as TwigLoaderInterface;
+
+class TwigServiceProvider extends ServiceProvider
+{
+    /** @var array */
+    protected $extensions = [
+        'config'      => Config::class,
+        'globals'     => Globals::class,
+        'session'     => Session::class,
+        'url'         => Url::class,
+        'translation' => Translation::class,
+    ];
+
+    public function register()
+    {
+        $this->registerTwigEngine();
+
+        foreach ($this->extensions as $alias => $class) {
+            $this->registerTwigExtensions($class, $alias);
+        }
+    }
+
+    public function boot()
+    {
+        /** @var Twig $renderer */
+        $renderer = $this->app->get('twig.environment');
+
+        foreach ($this->app->tagged('twig.extension') as $extension) {
+            $renderer->addExtension($extension);
+        }
+    }
+
+    protected function registerTwigEngine()
+    {
+        $viewsPath = $this->app->get('path.views');
+
+        $twigLoader = $this->app->make(TwigLoader::class, ['paths' => $viewsPath]);
+        $this->app->instance(TwigLoader::class, $twigLoader);
+        $this->app->instance(TwigLoaderInterface::class, $twigLoader);
+        $this->app->instance('twig.loader', $twigLoader);
+
+        $twig = $this->app->make(Twig::class);
+        $this->app->instance(Twig::class, $twig);
+        $this->app->instance('twig.environment', $twig);
+
+        $twigEngine = $this->app->make(TwigEngine::class);
+        $this->app->instance('renderer.twigEngine', $twigEngine);
+        $this->app->tag('renderer.twigEngine', ['renderer.engine']);
+    }
+
+    /**
+     * @param string $class
+     * @param string $alias
+     */
+    protected function registerTwigExtensions($class, $alias)
+    {
+        $alias = 'twig.extension.' . $alias;
+
+        $extension = $this->app->make($class);
+
+        $this->app->instance($class, $extension);
+        $this->app->instance($alias, $extension);
+
+        $this->app->tag($alias, ['twig.extension']);
+    }
+}
diff --git a/src/helpers.php b/src/helpers.php
index 95571a40..84f26dfa 100644
--- a/src/helpers.php
+++ b/src/helpers.php
@@ -3,10 +3,11 @@
 
 use Engelsystem\Application;
 use Engelsystem\Config\Config;
+use Engelsystem\Helpers\Translator;
 use Engelsystem\Http\Request;
 use Engelsystem\Http\Response;
-use Engelsystem\Renderer\Renderer;
 use Engelsystem\Http\UrlGenerator;
+use Engelsystem\Renderer\Renderer;
 use Symfony\Component\HttpFoundation\Session\SessionInterface;
 
 /**
@@ -119,6 +120,40 @@ function session($key = null, $default = null)
 }
 
 /**
+ * Translate the given message
+ *
+ * @param  string $key
+ * @param  array  $replace
+ * @return string|Translator
+ */
+function trans($key = null, $replace = [])
+{
+    /** @var Translator $translator */
+    $translator = app('translator');
+
+    if (is_null($key)) {
+        return $translator;
+    }
+
+    return $translator->translate($key, $replace);
+}
+
+/**
+ * Translate the given message
+ *
+ * @param  string $key
+ * @param  array  $replace
+ * @return string
+ */
+function __($key, $replace = [])
+{
+    /** @var Translator $translator */
+    $translator = app('translator');
+
+    return $translator->translate($key, $replace);
+}
+
+/**
  * @param string $path
  * @param array  $parameters
  * @return UrlGeneratorInterface|string
@@ -139,7 +174,7 @@ function url($path = null, $parameters = [])
  * @param mixed[] $data
  * @return Renderer|string
  */
-function view($template = null, $data = null)
+function view($template = null, $data = [])
 {
     $renderer = app('renderer');