Added translation support for twig templates

See https://twig-extensions.readthedocs.io/en/latest/i18n.html for documentation

composer.json

@@ -29,6 +29,7 @@
         "symfony/http-foundation": "^3.3",
         "symfony/psr-http-message-bridge": "^1.0",
         "twbs/bootstrap": "^3.3",
+        "twig/extensions": "^1.5",
         "twig/twig": "^2.5",
         "zendframework/zend-diactoros": "^1.7"
     },

config/app.php

@@ -10,13 +10,13 @@ return [
         \Engelsystem\Config\ConfigServiceProvider::class,
         \Engelsystem\Http\UrlGeneratorServiceProvider::class,
         \Engelsystem\Renderer\RendererServiceProvider::class,
-        \Engelsystem\Renderer\TwigServiceProvider::class,
         \Engelsystem\Database\DatabaseServiceProvider::class,
         \Engelsystem\Http\RequestServiceProvider::class,
         \Engelsystem\Http\SessionServiceProvider::class,
         \Engelsystem\Helpers\TranslationServiceProvider::class,
         \Engelsystem\Http\ResponseServiceProvider::class,
         \Engelsystem\Http\Psr7ServiceProvider::class,
+        \Engelsystem\Renderer\TwigServiceProvider::class,
         \Engelsystem\Middleware\RouteDispatcherServiceProvider::class,
         \Engelsystem\Middleware\RequestHandlerServiceProvider::class,
     ],

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];
+    }
+}

src/Renderer/TwigServiceProvider.php

@@ -6,6 +6,7 @@ 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;
@@ -18,6 +19,7 @@ class TwigServiceProvider extends ServiceProvider
         'globals'     => Globals::class,
         'session'     => Session::class,
         'url'         => Url::class,
+        'translation' => Translation::class,
     ];
 
     public function register()

templates/errors/default.twig

@@ -1,6 +1,6 @@
 {% extends "layouts/app.twig" %}
 
-{% block title %}Error {{ status }}{% endblock %}
+{% block title %}{% if status == 404 %}{{ __("Page not found") }}{% else %}Error {{ status }}{% endif %}{% endblock %}
 
 {% block content %}
     <div class="alert alert-info">{{ content }}</div>

tests/Unit/Renderer/Twig/Extensions/ExtensionTest.php

@@ -7,6 +7,27 @@ use Twig_Function as TwigFunction;
 
 abstract class ExtensionTest extends TestCase
 {
+    /**
+     * Assert that a twig filter was registered
+     *
+     * @param string         $name
+     * @param callable       $callback
+     * @param TwigFunction[] $functions
+     */
+    protected function assertFilterExists($name, $callback, $functions)
+    {
+        foreach ($functions as $function) {
+            if ($function->getName() != $name) {
+                continue;
+            }
+
+            $this->assertEquals($callback, $function->getCallable());
+            return;
+        }
+
+        $this->fail(sprintf('Filter %s not found', $name));
+    }
+
     /**
      * Assert that a twig function was registered
      *
@@ -45,4 +66,19 @@ abstract class ExtensionTest extends TestCase
 
         $this->fail(sprintf('Global %s not found', $name));
     }
+
+    /**
+     * Assert that a token parser was set
+     *
+     * @param $tokenParser
+     * @param $tokenParsers
+     */
+    protected function assertTokenParserExists($tokenParser, $tokenParsers)
+    {
+        $this->assertArraySubset(
+            [$tokenParser],
+            $tokenParsers,
+            sprintf('Token parser %s not found', get_class($tokenParser))
+        );
+    }
 }

tests/Unit/Renderer/Twig/Extensions/TranslationTest.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace Engelsystem\Test\Unit\Renderer\Twig\Extensions;
+
+use Engelsystem\Helpers\Translator;
+use Engelsystem\Renderer\Twig\Extensions\Translation;
+use PHPUnit\Framework\MockObject\MockObject;
+use Twig_Extensions_TokenParser_Trans as TranslationTokenParser;
+
+class TranslationTest extends ExtensionTest
+{
+    /**
+     * @covers \Engelsystem\Renderer\Twig\Extensions\Translation::__construct
+     * @covers \Engelsystem\Renderer\Twig\Extensions\Translation::getFilters
+     */
+    public function testGeFilters()
+    {
+        /** @var Translator|MockObject $translator */
+        $translator = $this->createMock(Translator::class);
+        /** @var TranslationTokenParser|MockObject $parser */
+        $parser = $this->createMock(TranslationTokenParser::class);
+
+        $extension = new Translation($translator, $parser);
+        $filters = $extension->getFilters();
+
+        $this->assertExtensionExists('trans', [$translator, 'translate'], $filters);
+    }
+
+    /**
+     * @covers \Engelsystem\Renderer\Twig\Extensions\Translation::getFunctions
+     */
+    public function testGetFunctions()
+    {
+        /** @var Translator|MockObject $translator */
+        $translator = $this->createMock(Translator::class);
+        /** @var TranslationTokenParser|MockObject $parser */
+        $parser = $this->createMock(TranslationTokenParser::class);
+
+        $extension = new Translation($translator, $parser);
+        $functions = $extension->getFunctions();
+
+        $this->assertExtensionExists('__', [$translator, 'translate'], $functions);
+    }
+
+    /**
+     * @covers \Engelsystem\Renderer\Twig\Extensions\Translation::getTokenParsers
+     */
+    public function testGetTokenParsers()
+    {
+        /** @var Translator|MockObject $translator */
+        $translator = $this->createMock(Translator::class);
+        /** @var TranslationTokenParser|MockObject $parser */
+        $parser = $this->createMock(TranslationTokenParser::class);
+
+        $extension = new Translation($translator, $parser);
+        $tokenParsers = $extension->getTokenParsers();
+
+        $this->assertTokenParserExists($parser, $tokenParsers);
+    }
+}