Question

I already learned how to create a Twig extension.

But now I need to create a tag, because I want to do something like this:

{% singleline %}
<div>
    <script>
        function bla() {
            alert('bla');
        }
    </script>
</div>
{% endsingleline %}

Result:

<div><script>function bla() { alert('bla'); }</script></div>

Any ideas?

Answer 1

You can do it by overriding getTokenParsers() method in your Twig Extension class, as described here.

To get a good example on how it’s done, take a look at Twig Extensions repository.
Specifically, take Debug as an example (here’s the Twig_Extensions_TokenParser_Debug class that’s passed to the method).

P.S. That said, you should take a look at the note added to Spaceless documentation page and maybe look into 3-rd party libraries like Tidy.