Minify HTML output from Flask application with Jinja2 templates

Question

Is there a Flask or Jinja2 configuration flag / extension to automatically minify the HTML output after rendering the template?

Answer 1

I use the following decorators

import bs4
import functools
import htmlmin


def prettify(route_function):
    @functools.wraps(route_function)
    def wrapped(*args, **kwargs):
        yielded_html = route_function(*args, **kwargs)
        soup = bs4.BeautifulSoup(yielded_html, 'html.parser')
        return soup.prettify()

    return wrapped

def uglify(route_function):
    @functools.wraps(route_function)
    def wrapped(*args, **kwargs):
        yielded_html = route_function(*args, **kwargs)
        minified_html = htmlmin.minify(yielded_html)
        return minified_html

    return wrapped

And simply wrapped the default render_template function like so

if app.debug:
    flask.render_template = prettify(flask.render_template)
else:
    flask.render_template = uglify(flask.render_template)

This has the added benefit of being auto added to the cache, since we don't actually touch app.route