Template Locations¶

Centralizing your templates in a single location simplifies the work of your designers. In addition, using this directory simplifies the notation used when referring to templates (e.g. $this->render('admin/post/show.html.twig') instead of $this->render('@SomeTwigNamespace/Admin/Posts/show.html.twig')).

This recommendation aligns with Twig best practices, where variables and template names use lowercased snake_case too (e.g. user_profile instead of userProfile and edit_form.html.twig instead of EditForm.html.twig).

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, 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 App\Utils;

class Markdown
{
    // ...

    public function toHtml(string $text): string
    {
        return $this->parser->text($text);
    }
}

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

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namespace App\Twig;

use App\Utils\Markdown;
use Twig\Extension\AbstractExtension;
use Twig\TwigFilter;

class AppExtension extends AbstractExtension
{
    private $parser;

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

    public function getFilters()
    {
        return [
            new TwigFilter('md2html', [$this, 'markdownToHtml'], [
                'is_safe' => ['html'],
                'pre_escape' => 'html',
            ]),
        ];
    }

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

And that's it!

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

Next: Forms