Templates
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Templates
When PHP was created 20 years ago, developers loved its simplicity and how well it blended HTML and dynamic code. But as time passed, other template languages - like Twig - were created to make templating even better.
Best Practice
Use Twig templating format for your templates.
Generally speaking, PHP templates are more verbose than Twig templates because they lack native support for lots of modern features needed by templates, like inheritance, automatic escaping and named arguments for filters and functions.
Twig is the default templating format in Symfony and has the largest community support of all non-PHP template engines (it's used in high profile projects such as Drupal 8).
Template Locations
Best Practice
Store the application templates in the templates/ directory at the root
of your project.
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')).
Best Practice
Use lowercased snake_case for directory and template names.
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).
Best Practice
Use a prefixed underscore for partial templates in template names.
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
Best Practice
Define your Twig extensions in the src/Twig/ directory. Your
application will automatically detect them and configure them.
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
