Add Best Practice guideline for partials/include

[timonf]

Hi there,

I was wondering if there is no Best Practice guide for partials/includes. So I would recommend to use a single prefixed underscore to determine such partials easily like in the Symfony demo application: https://github.com/symfony/demo/tree/master/templates/blog

I saw often other solutions like @SomeBundle:Partials/post_form.html.twig. But I like the approach from the Symfony demo application, so it should be a Best Practice guideline :)

Regards,
Timon

[wouterj]

👍 I like it.

/cc @javiereguiluz please share your thoughts on this as you're the best practices master :)

[javiereguiluz]

I agree with this proposal! the leading underscore has been an unofficial best practice for more than 12 years (since symfony 1) so it's time to make it official!

If I may, I'd like to propose some minor rewordings to this proposal:

.. best-practice::

    Prefix the file name of partial templates with an underscore.

You often want to reuse template code using the ``include()`` function to avoid
redundant code. To better differentiate those partials in the filesystem, you
should prefix their file names with a single underscore (e.g. ``_footer.html.twig``).

Thanks!

[weaverryan]

I like it! Thank you Timon!