Sybren A. Stüvel
12272750c3
Static files are now served with an 8-character hash before the last
extension. For example, `tutti.min.js` is now served as
`tutti.min.abcd1234.js`. When doing a request the hash is removed before
serving the static file.
The hash must be 8 characters long, and is taken from STATIC_FILE_HASH.
It is up to the deployment to change this configuration variable
whenever static files change. This forces browsers that download newly
deployed HTML to also refresh the dependencies (most importantly
JS/CSS).
For this to work, the URL must be built with `url_for('static_xxx',
filename='/path/to/file')`. The 'static' module still returns regular,
hashless URLs.
77 lines
2.1 KiB
Python
77 lines
2.1 KiB
Python
import re
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import functools
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import flask
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import werkzeug.routing
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class HashedPathConverter(werkzeug.routing.PathConverter):
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"""Allows for files `xxx.yyy.js` to be served as `xxx.yyy.abc123.js`.
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The hash code is placed before the last extension.
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"""
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weight = 300
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# Hash length is hard-coded to 8 characters for now.
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hash_re = re.compile(r'\.([a-zA-Z0-9]{8})(?=\.[^.]+$)')
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@functools.lru_cache(maxsize=1024)
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def to_python(self, from_url: str) -> str:
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return self.hash_re.sub('', from_url)
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@functools.lru_cache(maxsize=1024)
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def to_url(self, filepath: str) -> str:
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try:
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dotidx = filepath.rindex('.')
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except ValueError:
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# Happens when there is no dot. Very unlikely.
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return filepath
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current_hash = flask.current_app.config['STATIC_FILE_HASH']
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before, after = filepath[:dotidx], filepath[dotidx:]
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return f'{before}.{current_hash}{after}'
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def add_response_headers(headers: dict):
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"""This decorator adds the headers passed in to the response"""
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def decorator(f):
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@functools.wraps(f)
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def decorated_function(*args, **kwargs):
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resp = flask.make_response(f(*args, **kwargs))
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h = resp.headers
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for header, value in headers.items():
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h[header] = value
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return resp
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return decorated_function
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return decorator
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def vary_xhr():
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"""View function decorator; adds HTTP header "Vary: X-Requested-With" to the response"""
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def decorator(f):
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header_adder = add_response_headers({'Vary': 'X-Requested-With'})
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return header_adder(f)
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return decorator
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def ensure_schema(url: str) -> str:
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"""Return the same URL with the configured PREFERRED_URL_SCHEME."""
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import urllib.parse
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if not url:
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return url
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bits = urllib.parse.urlsplit(url, allow_fragments=True)
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if not bits[0] and not bits[1]:
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# don't replace the schema if there is not even a hostname.
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return url
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scheme = flask.current_app.config.get('PREFERRED_URL_SCHEME', 'https')
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bits = (scheme, *bits[1:])
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return urllib.parse.urlunsplit(bits)
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