Create MinifyHTMLMiddleware

[Artem Skoretskiy]

We need a simple middleware that would compactify all the pages before sending to the client. It should be basically the same as spaceless templatetag, but for whole response.

It will reduce page size significantly -- that is important for any production site. Middleware makes sense because you don't have to care about manually using this tag in templates. It makes sense even when you use Gzip as after decompression it needs to be parsed by browser -- so size still matters.

Here is the code. Nothing special, we just use Django internals.

from django.utils.encoding import DjangoUnicodeDecodeError
from django.utils.html import strip_spaces_between_tags as minify_html

class MinifyHTMLMiddleware(object):
    def process_response(self, request, response):
        if 'text/html' in response['Content-Type']:
            try:
                response.content = minify_html(response.content.strip())
            except DjangoUnicodeDecodeError:
                pass
        return response

The idea was taken from django-pipeline. But since it makes sense and it only uses Django internals -- it would be great to have it in Django itself.

[Aymeric Augustin]

This can modify the semantic of the HTML. Spaces between inline elements *are* significant. (Between block elements, I believe they aren't, but I wouldn't swear it can't create layout bugs in IE.)

The implementation looks a bit specific — why only 'text/html'? why ignore DjangoUnicodeDecodeError?

I'd like to see a benchmark of the speed benefits: I doubt that whitespace has a noticeable impact, even on low-end hardware.

Finally this is easily implemented outside of Django.

For these four reasons, I don't think this really belongs in Django. Thanks for the suggestion, though!