lektor_minify_html.py

from lektor.pluginsystem import Plugin
import minify_html
import re

class MinifyHtmlPlugin(Plugin):
    name = 'Lektor minify html'
    description = u'Minify content using minify-html'

    def is_valid_minify(self, filename: str) -> bool:
        regex = r".+\.(html|js|css)$"
        return bool(re.match(regex, filename))

    def minify(self, source: str) -> str:
        return minify_html.minify(source, minify_js=True, minify_css=True)

    def on_after_build(self, builder, **extra) -> None:
        if not len(extra["prog"].artifacts):
            return

        dst_filename = extra["prog"].artifacts[0].dst_filename

        if not self.is_valid_minify(dst_filename):
            return

        try:
            with open(dst_filename, 'r+') as file:
                html_content = file.read()
                file.seek(0)
                file.write(self.minify(html_content))
                file.truncate()
        except UnicodeDecodeError:
            # Minification is skipped.
            return