As long as popular libraries (e.g. Celery) require click 7, depending
on Click 8 in Flask makes it hard to test the latest version (and its
other dependencies) in existing applications.
Wrapped functions are not comparable, see
https://bugs.python.org/issue3564, therefore a marker is used to note
when the function has been sync wrapped to allow comparison with the
wrapped function instead.
This ensures that multiple route decorators work without raising
exceptions i.e.,
@app.route("/")
@app.route("/a")
async def index():
...
works.
This allows blueprints to be nested within blueprints via a new
Blueprint.register_blueprint method. This should provide a use case
that has been desired for the past ~10 years.
This works by setting the endpoint name to be the blueprint names,
from parent to child delimeted by "." and then iterating over the
blueprint names in reverse order in the app (from most specific to
most general). This means that the expectation of nesting a blueprint
within a nested blueprint is met.
See this Python bug https://bugs.python.org/issue33261. The
iscoroutinefunction doesn't recognise partially wrapped coroutine
functions as coroutine functions - which is problematic as the
coroutines will be called as if they are sync, which results in
un-awaited coroutines.
This allows extensions to override the Flask.ensure_sync method and
have the change apply to blueprints as well. Without this change it is
possible for differing blueprints to have differing ensure_sync
approaches depending on the extension used - which would likely result
in event-loop blocking issues.
This also allows blueprints to have a custom ensure_sync, although
this is a by product rather than an expected use case.
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.
This code originates from supporting Python 2.4. Dicts are ordered in
supported Pythons as of 3.6. An OrderedDict could be used to indicate
that order matters, but is not since we don't rely on the implementation
differences.
This code originates from the Python 2.4 supporting version of Flask,
with defaultdicts being added in 2.5. Using defaultdict makes the
intentional usage clearer, and slightly simplifies the code.
This takes a popular API whereby instead of passing the HTTP method as
an argument to route it is instead used as the method name i.e.
@app.route("/", methods=["POST"])
is now writeable as,
@app.post("/")
This is simply syntatic sugar, it doesn't do anything else, but makes
it slightly easier for users.
I've included all the methods that are relevant and aren't auto
generated i.e. not connect, head, options, and trace.
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.
Flask's client.open mirrors Werkzeug's for processing an existing
environ.
Always test with latest code for other Pallets projects. This will
be changed back once the new versions are released.
Flask instances with static folders were creating a reference cycle
via their "static" view function (which held a strong reference back
to the Flask instance to call its `send_static_file` method). This
prevented CPython from freeing the memory for a Flask instance
when all external references to it were released.
Now use a weakref for the back reference to avoid this.
Co-authored-by: Joshua Bronson <jab@users.noreply.github.com>
Commit 2ae740dd49 probably inadvertently
changed to iterate over a set of "create_app", "make_app" to discover
application factory functions. As sets don't guarantee order,
differences in the implementation of the type can make it
non-deterministic which factory function is used if a project implements
both. Revert to using a tuple.
Signed-off-by: Nils Philippsen <nils@redhat.com>
