documentation/_extensions/redirects.py
2020-04-06 16:31:27 +02:00

65 lines
2.3 KiB
Python

# Adapted from https://github.com/sphinx-contrib/redirects
import os
import re
from pathlib import Path
from sphinx.builders import html as builders
from sphinx.util import logging as logging
TEMPLATE = '<html><head><meta http-equiv="refresh" content="0; url=%s"/></head></html>'
logger = logging.getLogger(__name__)
def generate_redirects(app):
path = os.path.join(app.srcdir, app.config.redirects_file)
if not os.path.exists(path):
logger.debug("Could not find redirects file at '%s'", path)
return
source_suffix = next(iter(app.config.source_suffix))
if not type(app.builder) == builders.StandaloneHTMLBuilder:
logger.info("Redirects are only supported by the 'html' builder. Skipping...")
return
with open(path) as redirects:
escaped_source_suffix = source_suffix.replace('.', '\.')
pattern = re.compile(
r'^[ \t]*([\w\-/]+{0})[ \t]+([\w\-/]+{0})[ \t]*(#.*)?$'.format(escaped_source_suffix)
)
for line in redirects.readlines():
# Exclude comment or empty lines
if not line.rstrip() or line.startswith('#'):
continue
match_result = pattern.match(line)
# Log malformed rules
if not match_result:
logger.error(
"Ignoring malformed redirection: {0}"
"Please use this format: old_page{1} new_page{1} # optional comment".format(
line, source_suffix)
)
continue
# Parse the rule
from_file, to_file, _ = match_result.groups()
logger.debug("Redirecting '%s' to '%s'", from_file, to_file)
# Prepare source and destination paths
to_path_prefix = '../' * from_file.count('/')
from_html_file = from_file.replace(source_suffix, '.html')
to_html_file = to_path_prefix + to_file.replace(source_suffix, '.html')
absolute_from_path = Path(app.builder.outdir) / from_html_file
# Create the redirection
absolute_from_path.parent.mkdir(parents=True, exist_ok=True)
absolute_from_path.write_text(TEMPLATE % to_html_file)
def setup(app):
app.add_config_value('redirects_file', 'redirects', 'env')
app.connect('builder-inited', generate_redirects)