Symfony2 - checking if file exists

Question

I have a loop in Twig template, which returns multiple values. Most important - an ID of my entry. When I didn\'t use any framework nor template engine, I used simply

Answer 1

I've created a Twig function which is an extension of the answers I have found on this topic. My asset_if function takes two parameters: the first one is the path for the asset to display. The second parameter is the fallback asset, if the first asset does not exist.

Create your extension file:

src/Showdates/FrontendBundle/Twig/Extension/ConditionalAssetExtension.php:

container = $container;
    }

    /**
     * Returns a list of functions to add to the existing list.
     *
     * @return array An array of functions
     */
    public function getFunctions()
    {
        return array(
            'asset_if' => new \Twig_Function_Method($this, 'asset_if'),
        );
    }

    /**
     * Get the path to an asset. If it does not exist, return the path to the
     * fallback path.
     * 
     * @param string $path the path to the asset to display
     * @param string $fallbackPath the path to the asset to return in case asset $path does not exist
     * @return string path
     */
    public function asset_if($path, $fallbackPath)
    {
        // Define the path to look for
        $pathToCheck = realpath($this->container->get('kernel')->getRootDir() . '/../web/') . '/' . $path;

        // If the path does not exist, return the fallback image
        if (!file_exists($pathToCheck))
        {
            return $this->container->get('templating.helper.assets')->getUrl($fallbackPath);
        }

        // Return the real image
        return $this->container->get('templating.helper.assets')->getUrl($path);
    }

    /**
     * Returns the name of the extension.
     *
     * @return string The extension name
     */
    public function getName()
    {
       return 'asset_if';
    }
}

Register your service (app/config/config.yml or src/App/YourBundle/Resources/services.yml):

services:
    showdates.twig.asset_if_extension:
        class: Showdates\FrontendBundle\Twig\Extension\ConditionalAssetExtension
        arguments: ['@service_container']
        tags:
          - { name: twig.extension }

Now use it in your templates like this: