TwigExtension.md

Twig Extension

• ThemeExtension示例

    <?php
    //src/KitWebBundle/Twig/ThemeExtension.php
    namespace KitWebBundle\Twig;
    
    use Symfony\Component\DependencyInjection\ContainerInterface;
    
    class ThemeExtension extends \Twig\Extension\AbstractExtension implements \Twig\Extension\GlobalsInterface
    {
        private $container;
        
        public function __construct(ContainerInterface $container)
        {
            $this->container = $container;
        }
        // 注册一个全局变量
        public function getGlobals()
        {
            return array(
                'theme_name' => $this->getThemeName()
            );
        }
    	// 注册一个名为theme的过滤器
        public function getFilters()
        {
            return array(
                new \Twig\TwigFilter('theme', array($this, 'themeFilter')),
            );
        }
        // 注册一个theme的函数
        public function getFunctions()
        {
            return array(
                new \Twig\TwigFunction('theme', array($this, 'themeFunction')),
            );
        }
        
        public function themeFilter($resource, $default = 'Default')
        {
            
            return 'theme/'. $this->getThemeName($default) . '/' . $resource;
        }
        
        public function themeFunction($resource, $default = 'Default')
        {
            return 'theme/'. $this->getThemeName($default) . '/' . $resource;
        }
        
        private function getThemeName($default = 'Default')
        {
            /**
             * @var \KitAdminBundle\Service\ThemeService $themeService
             */
            $themeService = $this->container->get('kit_admin.theme_service');
            return $themeService->get($default);
        }
    }
  

• 注册服务

    # app/config/services.yml
    services:
    	twig.extension.theme_extension:
    		class: KitWebBundle\Twig\ThemeExtension
    		arguments: ["@service_container"]
    		tags:
     		   - { name: twig.extension } // tag表明为twig的扩展，非常重要
  

• 使用

    {# in twig #}
    {{ theme_name }} //使用注册的全局变量
    {{ asset(theme('style.css')) }} // 使用扩展函数
    {{ asset('style.css' | theme )}} //使用扩展过滤器
  

• 高级参数

  • is_safe

      class MacroExtension extends \Twig_Extension
      {
    
          public function getFunctions()
          {
              return array(
                  new \Twig\TwigFunction('macro_no_content', [
                      $this,
                      'noContent'
                  ], [
                      'is_safe' => [
                          'html'
                      ]
                  ])
              );
          }
    
          public function noContent($num)
          {
              return <<<EOF
              <tr>
              <td colspan="$num" align="center">
              <img src="/public/img/no_content.gif"/>
              </td>
              </tr>
      EOF;
          }
      }
    

  • needs_context

  • needs_environment

• 官方Extension仓库:github.com/twigphp/Twig-extensions