import re
from aiohttp.web_exceptions import HTTPMovedPermanently
from aiohttp.web_urldispatcher import SystemRoute
__all__ = (
'middleware',
'normalize_path_middleware',
)
async def _check_request_resolves(request, path):
alt_request = request.clone(rel_url=path)
match_info = await request.app.router.resolve(alt_request)
alt_request._match_info = match_info
if not isinstance(match_info.route, SystemRoute):
return True, alt_request
return False, request
def middleware(f):
f.__middleware_version__ = 1
return f
def normalize_path_middleware(
*, append_slash=True, merge_slashes=True,
redirect_class=HTTPMovedPermanently):
"""
Middleware that normalizes the path of a request. By normalizing
it means:
- Add a trailing slash to the path.
- Double slashes are replaced by one.
The middleware returns as soon as it finds a path that resolves
correctly. The order if all enable is 1) merge_slashes, 2) append_slash
and 3) both merge_slashes and append_slash. If the path resolves with
at least one of those conditions, it will redirect to the new path.
If append_slash is True append slash when needed. If a resource is
defined with trailing slash and the request comes without it, it will
append it automatically.
If merge_slashes is True, merge multiple consecutive slashes in the
path into one.
"""
@middleware
async def impl(request, handler):
if isinstance(request.match_info.route, SystemRoute):
paths_to_check = []
if '?' in request.raw_path:
path, query = request.raw_path.split('?', 1)
query = '?' + query
else:
query = ''
path = request.raw_path
if merge_slashes:
paths_to_check.append(re.sub('//+', '/', path))
if append_slash and not request.path.endswith('/'):
paths_to_check.append(path + '/')
if merge_slashes and append_slash:
paths_to_check.append(
re.sub('//+', '/', path + '/'))
for path in paths_to_check:
resolves, request = await _check_request_resolves(
request, path)
if resolves:
raise redirect_class(request.path + query)
return await handler(request)
return impl
def _fix_request_current_app(app):
@middleware
async def impl(request, handler):
with request.match_info.set_current_app(app):
return await handler(request)
return impl