Werkzeug offers a ContextVar replacement for Python < 3.7, however it
doesn't work across asyncio tasks, hence it makes sense to error out
rather than find there are odd bugs.
Note the docs build requires the latest (dev) Werkzeug due to this
change (to import ContextVar from werkzeug.local).
This allows for async functions to be passed to the Flask class
instance, for example as a view function,
@app.route("/")
async def index():
return "Async hello"
this comes with a cost though of poorer performance than using the
sync equivalent.
asgiref is the standard way to run async code within a sync context,
and is used in Django making it a safe and sane choice for this.
The implementations were moved to Werkzeug, Flask's functions become
wrappers around Werkzeug to pass some Flask-specific values.
cache_timeout is renamed to max_age. SEND_FILE_MAX_AGE_DEFAULT,
app.send_file_max_age_default, and app.get_send_file_max_age defaults
to None. This tells the browser to use conditional requests rather than
a 12 hour cache.
attachment_filename is renamed to download_name, and is always sent if
a name is known.
Deprecate helpers.safe_join in favor of werkzeug.utils.safe_join.
Removed most of the send_file tests, they're tested in Werkzeug.
In the file upload example, renamed the uploaded_file view to
download_file to avoid a common source of confusion.
* No longer causes AttributeError: 'PosixPath' object has no
attribute 'rstrip'.
* This was broken by e6178fe489
which was released in 1.1.2.
* Add a regression test that now passes.
See #3557.
