extensions.md

layout	title	description	redirect_from
default	Extensions	Creating custom extensions to add new syntax and other custom functionality	/customization/extensions/

Extensions

Extensions provide a way to group related parsers, renderers, etc. together with pre-defined priorities, configuration settings, etc. They are perfect for distributing your customizations as reusable, open-source packages that others can plug into their own projects!

To create an extension, simply create a new class implementing ExtensionInterface. This has a single method where you're given a ConfigurableEnvironmentInterface to register whatever things you need to. For example:

use League\CommonMark\Extension\ExtensionInterface;
use League\CommonMark\Environment\ConfigurableEnvironmentInterface;

final class EmojiExtension implements ExtensionInterface
{
    public function register(ConfigurableEnvironmentInterface $environment): void
    {
        $environment
            // TODO: Create the EmojiParser, Emoji, and EmojiRenderer classes
            ->addInlineParser(new EmojiParser(), 20)
            ->addInlineRenderer(Emoji::class, new EmojiRenderer(), 0)
        ;
    }
}

To hook up your new extension to the Environment, simply do this:

use League\CommonMark\Environment\Environment;
use League\CommonMark\Extension\CommonMark\CommonMarkCoreExtension;
use League\CommonMark\MarkdownConverter;

$environment = new Environment();
$environment->addExtension(new CommonMarkCoreExtension());
$environment->addExtension(new EmojiExtension());

$converter = new MarkdownConverter($environment);
echo $converter->convert('Hello! :wave:');