Template Locations

Traditionally, Symfony developers stored the application templates in the Resources/views/ directory of each bundle. Then they used the Twig namespaced path to refer to them (e.g. @AcmeDemo/Default/index.html.twig).

But for the templates used in your application, it's much more convenient to store them in the app/Resources/views/ directory. For starters, this drastically simplifies their logical names:

Another advantage is that centralizing your templates simplifies the work of your designers. They don't need to look for templates in lots of directories scattered through lots of bundles.

You often want to reuse template code using the include function to avoid redundant code. To determine those partials easily in the filesystem you should prefix partials and any other template without HTML body or extends tag with a single underscore.

Twig Extensions

Our application needs a custom md2html Twig filter so that we can transform the Markdown contents of each post into HTML.

To do this, first, install the excellent Parsedown Markdown parser as a new dependency of the project:

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$ composer require erusev/parsedown

Then, create a new Markdown class that will be used later by the Twig extension. It just needs to define one single method to transform Markdown content into HTML:

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namespace AppBundle\Utils;

class Markdown
{
    private $parser;

    public function __construct()
    {
        $this->parser = new \Parsedown();
    }

    public function toHtml($text)
    {
        $html = $this->parser->text($text);

        return $html;
    }
}

Next, create a new Twig extension and define a new filter called md2html using the Twig_SimpleFilter class. Inject the newly defined Markdown class in the constructor of the Twig extension:

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namespace AppBundle\Twig;

use AppBundle\Utils\Markdown;

class AppExtension extends \Twig_Extension
{
    private $parser;

    public function __construct(Markdown $parser)
    {
        $this->parser = $parser;
    }

    public function getFilters()
    {
        return array(
            new \Twig_SimpleFilter(
                'md2html',
                array($this, 'markdownToHtml'),
                array('is_safe' => array('html'), 'pre_escape' => 'html')
            ),
        );
    }

    public function markdownToHtml($content)
    {
        return $this->parser->toHtml($content);
    }

    public function getName()
    {
        return 'app_extension';
    }
}

And that's it!

If you're using the default services.yml configuration, you're done! Symfony will automatically know about your new service and tag it to be used as a Twig extension.

Next: Forms