flask/CHANGES.rst

.. currentmodule:: flask

Version 1.0.4
-------------

Unreleased

-   The key information for ``BadRequestKeyError`` is no longer cleared
    outside debug mode, so error handlers can still access it. This
    requires upgrading to Werkzeug 0.15.5. :issue:`3249`
-   ``send_file`` url quotes the ":" and "/" characters for more
    compatible UTF-8 filename support in some browsers. :issue:`3074`
-   Fixes for PEP451 import loaders and pytest 5.x.  :issue:`3275`
-   Show message about dotenv on stderr instead of stdout.  :issue:`3285`


Version 1.0.3
-------------

Released 2019-05-17

-   :func:`send_file` encodes filenames as ASCII instead of Latin-1
    (ISO-8859-1). This fixes compatibility with Gunicorn, which is
    stricter about header encodings than PEP 3333. :issue:`2766`
-   Allow custom CLIs using ``FlaskGroup`` to set the debug flag without
    it always being overwritten based on environment variables.
    :pr:`2765`
-   ``flask --version`` outputs Werkzeug's version and simplifies the
    Python version. :pr:`2825`
-   :func:`send_file` handles an ``attachment_filename`` that is a
    native Python 2 string (bytes) with UTF-8 coded bytes. :issue:`2933`
-   A catch-all error handler registered for ``HTTPException`` will not
    handle ``RoutingExcpetion``, which is used internally during
    routing. This fixes the unexpected behavior that had been introduced
    in 1.0. :pr:`2986`
-   Passing the ``json`` argument to ``app.test_client`` does not
    push/pop an extra app context. :issue:`2900`


Version 1.0.2
-------------

Released 2018-05-02

-   Fix more backwards compatibility issues with merging slashes between
    a blueprint prefix and route. :pr:`2748`
-   Fix error with ``flask routes`` command when there are no routes.
    :issue:`2751`


Version 1.0.1
-------------

Released 2018-04-29

-   Fix registering partials (with no ``__name__``) as view functions.
    :pr:`2730`
-   Don't treat lists returned from view functions the same as tuples.
    Only tuples are interpreted as response data. :issue:`2736`
-   Extra slashes between a blueprint's ``url_prefix`` and a route URL
    are merged. This fixes some backwards compatibility issues with the
    change in 1.0. :issue:`2731`, :issue:`2742`
-   Only trap ``BadRequestKeyError`` errors in debug mode, not all
    ``BadRequest`` errors. This allows ``abort(400)`` to continue
    working as expected. :issue:`2735`
-   The ``FLASK_SKIP_DOTENV`` environment variable can be set to ``1``
    to skip automatically loading dotenv files. :issue:`2722`


Version 1.0
-----------

Released 2018-04-26

-   Python 2.6 and 3.3 are no longer supported.
-   Bump minimum dependency versions to the latest stable versions:
    Werkzeug >= 0.14, Jinja >= 2.10, itsdangerous >= 0.24, Click >= 5.1.
    :issue:`2586`
-   Skip :meth:`app.run <Flask.run>` when a Flask application is run
    from the command line. This avoids some behavior that was confusing
    to debug.
-   Change the default for :data:`JSONIFY_PRETTYPRINT_REGULAR` to
    ``False``. :func:`~json.jsonify` returns a compact format by
    default, and an indented format in debug mode. :pr:`2193`
-   :meth:`Flask.__init__ <Flask>` accepts the ``host_matching``
    argument and sets it on :attr:`~Flask.url_map`. :issue:`1559`
-   :meth:`Flask.__init__ <Flask>` accepts the ``static_host`` argument
    and passes it as the ``host`` argument when defining the static
    route. :issue:`1559`
-   :func:`send_file` supports Unicode in ``attachment_filename``.
    :pr:`2223`
-   Pass ``_scheme`` argument from :func:`url_for` to
    :meth:`~Flask.handle_url_build_error`. :pr:`2017`
-   :meth:`~Flask.add_url_rule` accepts the
    ``provide_automatic_options`` argument to disable adding the
    ``OPTIONS`` method. :pr:`1489`
-   :class:`~views.MethodView` subclasses inherit method handlers from
    base classes. :pr:`1936`
-   Errors caused while opening the session at the beginning of the
    request are handled by the app's error handlers. :pr:`2254`
-   Blueprints gained :attr:`~Blueprint.json_encoder` and
    :attr:`~Blueprint.json_decoder` attributes to override the app's
    encoder and decoder. :pr:`1898`
-   :meth:`Flask.make_response` raises ``TypeError`` instead of
    ``ValueError`` for bad response types. The error messages have been
    improved to describe why the type is invalid. :pr:`2256`
-   Add ``routes`` CLI command to output routes registered on the
    application. :pr:`2259`
-   Show warning when session cookie domain is a bare hostname or an IP
    address, as these may not behave properly in some browsers, such as
    Chrome. :pr:`2282`
-   Allow IP address as exact session cookie domain. :pr:`2282`
-   ``SESSION_COOKIE_DOMAIN`` is set if it is detected through
    ``SERVER_NAME``. :pr:`2282`
-   Auto-detect zero-argument app factory called ``create_app`` or
    ``make_app`` from ``FLASK_APP``. :pr:`2297`
-   Factory functions are not required to take a ``script_info``
    parameter to work with the ``flask`` command. If they take a single
    parameter or a parameter named ``script_info``, the
    :class:`~cli.ScriptInfo` object will be passed. :pr:`2319`
-   ``FLASK_APP`` can be set to an app factory, with arguments if
    needed, for example ``FLASK_APP=myproject.app:create_app('dev')``.
    :pr:`2326`
-   ``FLASK_APP`` can point to local packages that are not installed in
    editable mode, although ``pip install -e`` is still preferred.
    :pr:`2414`
-   The :class:`~views.View` class attribute
    :attr:`~views.View.provide_automatic_options` is set in
    :meth:`~views.View.as_view`, to be detected by
    :meth:`~Flask.add_url_rule`. :pr:`2316`
-   Error handling will try handlers registered for ``blueprint, code``,
    ``app, code``, ``blueprint, exception``, ``app, exception``.
    :pr:`2314`
-   ``Cookie`` is added to the response's ``Vary`` header if the session
    is accessed at all during the request (and not deleted). :pr:`2288`
-   :meth:`~Flask.test_request_context` accepts ``subdomain`` and
    ``url_scheme`` arguments for use when building the base URL.
    :pr:`1621`
-   Set :data:`APPLICATION_ROOT` to ``'/'`` by default. This was already
    the implicit default when it was set to ``None``.
-   :data:`TRAP_BAD_REQUEST_ERRORS` is enabled by default in debug mode.
    ``BadRequestKeyError`` has a message with the bad key in debug mode
    instead of the generic bad request message. :pr:`2348`
-   Allow registering new tags with
    :class:`~json.tag.TaggedJSONSerializer` to support storing other
    types in the session cookie. :pr:`2352`
-   Only open the session if the request has not been pushed onto the
    context stack yet. This allows :func:`~stream_with_context`
    generators to access the same session that the containing view uses.
    :pr:`2354`
-   Add ``json`` keyword argument for the test client request methods.
    This will dump the given object as JSON and set the appropriate
    content type. :pr:`2358`
-   Extract JSON handling to a mixin applied to both the
    :class:`Request` and :class:`Response` classes. This adds the
    :meth:`~Response.is_json` and :meth:`~Response.get_json` methods to
    the response to make testing JSON response much easier. :pr:`2358`
-   Removed error handler caching because it caused unexpected results
    for some exception inheritance hierarchies. Register handlers
    explicitly for each exception if you want to avoid traversing the
    MRO. :pr:`2362`
-   Fix incorrect JSON encoding of aware, non-UTC datetimes. :pr:`2374`
-   Template auto reloading will honor debug mode even even if
    :attr:`~Flask.jinja_env` was already accessed. :pr:`2373`
-   The following old deprecated code was removed. :issue:`2385`

    -   ``flask.ext`` - import extensions directly by their name instead
        of through the ``flask.ext`` namespace. For example,
        ``import flask.ext.sqlalchemy`` becomes
        ``import flask_sqlalchemy``.
    -   ``Flask.init_jinja_globals`` - extend
        :meth:`Flask.create_jinja_environment` instead.
    -   ``Flask.error_handlers`` - tracked by
        :attr:`Flask.error_handler_spec`, use :meth:`Flask.errorhandler`
        to register handlers.
    -   ``Flask.request_globals_class`` - use
        :attr:`Flask.app_ctx_globals_class` instead.
    -   ``Flask.static_path`` - use :attr:`Flask.static_url_path`
        instead.
    -   ``Request.module`` - use :attr:`Request.blueprint` instead.

-   The :attr:`Request.json` property is no longer deprecated.
    :issue:`1421`
-   Support passing a :class:`~werkzeug.test.EnvironBuilder` or ``dict``
    to :meth:`test_client.open <werkzeug.test.Client.open>`. :pr:`2412`
-   The ``flask`` command and :meth:`Flask.run` will load environment
    variables from ``.env`` and ``.flaskenv`` files if python-dotenv is
    installed. :pr:`2416`
-   When passing a full URL to the test client, the scheme in the URL is
    used instead of :data:`PREFERRED_URL_SCHEME`. :pr:`2430`
-   :attr:`Flask.logger` has been simplified. ``LOGGER_NAME`` and
    ``LOGGER_HANDLER_POLICY`` config was removed. The logger is always
    named ``flask.app``. The level is only set on first access, it
    doesn't check :attr:`Flask.debug` each time. Only one format is
    used, not different ones depending on :attr:`Flask.debug`. No
    handlers are removed, and a handler is only added if no handlers are
    already configured. :pr:`2436`
-   Blueprint view function names may not contain dots. :pr:`2450`
-   Fix a ``ValueError`` caused by invalid ``Range`` requests in some
    cases. :issue:`2526`
-   The development server uses threads by default. :pr:`2529`
-   Loading config files with ``silent=True`` will ignore
    :data:`~errno.ENOTDIR` errors. :pr:`2581`
-   Pass ``--cert`` and ``--key`` options to ``flask run`` to run the
    development server over HTTPS. :pr:`2606`
-   Added :data:`SESSION_COOKIE_SAMESITE` to control the ``SameSite``
    attribute on the session cookie. :pr:`2607`
-   Added :meth:`~flask.Flask.test_cli_runner` to create a Click runner
    that can invoke Flask CLI commands for testing. :pr:`2636`
-   Subdomain matching is disabled by default and setting
    :data:`SERVER_NAME` does not implicily enable it. It can be enabled
    by passing ``subdomain_matching=True`` to the ``Flask`` constructor.
    :pr:`2635`
-   A single trailing slash is stripped from the blueprint
    ``url_prefix`` when it is registered with the app. :pr:`2629`
-   :meth:`Request.get_json` doesn't cache the result if parsing fails
    when ``silent`` is true. :issue:`2651`
-   :func:`Request.get_json` no longer accepts arbitrary encodings.
    Incoming JSON should be encoded using UTF-8 per :rfc:`8259`, but
    Flask will autodetect UTF-8, -16, or -32. :pr:`2691`
-   Added :data:`MAX_COOKIE_SIZE` and :attr:`Response.max_cookie_size`
    to control when Werkzeug warns about large cookies that browsers may
    ignore. :pr:`2693`
-   Updated documentation theme to make docs look better in small
    windows. :pr:`2709`
-   Rewrote the tutorial docs and example project to take a more
    structured approach to help new users avoid common pitfalls.
    :pr:`2676`


Version 0.12.4
--------------

Released 2018-04-29

-   Repackage 0.12.3 to fix package layout issue. :issue:`2728`


Version 0.12.3
--------------

Released 2018-04-26

-   :func:`Request.get_json` no longer accepts arbitrary encodings.
    Incoming JSON should be encoded using UTF-8 per :rfc:`8259`, but
    Flask will autodetect UTF-8, -16, or -32. :issue:`2692`
-   Fix a Python warning about imports when using ``python -m flask``.
    :issue:`2666`
-   Fix a ``ValueError`` caused by invalid ``Range`` requests in some
    cases.


Version 0.12.2
--------------

Released 2017-05-16

-   Fix a bug in ``safe_join`` on Windows.


Version 0.12.1
--------------

Released 2017-03-31

-   Prevent ``flask run`` from showing a ``NoAppException`` when an
    ``ImportError`` occurs within the imported application module.
-   Fix encoding behavior of ``app.config.from_pyfile`` for Python 3.
    :issue:`2118`
-   Use the ``SERVER_NAME`` config if it is present as default values
    for ``app.run``. :issue:`2109`, :pr:`2152`
-   Call ``ctx.auto_pop`` with the exception object instead of ``None``,
    in the event that a ``BaseException`` such as ``KeyboardInterrupt``
    is raised in a request handler.


Version 0.12
------------

Released 2016-12-21, codename Punsch

-   The cli command now responds to ``--version``.
-   Mimetype guessing and ETag generation for file-like objects in
    ``send_file`` has been removed. :issue:`104`, :pr`1849`
-   Mimetype guessing in ``send_file`` now fails loudly and doesn't fall
    back to ``application/octet-stream``. :pr:`1988`
-   Make ``flask.safe_join`` able to join multiple paths like
    ``os.path.join`` :pr:`1730`
-   Revert a behavior change that made the dev server crash instead of
    returning an Internal Server Error. :pr:`2006`
-   Correctly invoke response handlers for both regular request
    dispatching as well as error handlers.
-   Disable logger propagation by default for the app logger.
-   Add support for range requests in ``send_file``.
-   ``app.test_client`` includes preset default environment, which can
    now be directly set, instead of per ``client.get``.
-   Fix crash when running under PyPy3. :pr:`1814`


Version 0.11.1
--------------

Released 2016-06-07

-   Fixed a bug that prevented ``FLASK_APP=foobar/__init__.py`` from
    working. :pr:`1872`


Version 0.11
------------

Released 2016-05-29, codename Absinthe

-   Added support to serializing top-level arrays to
    :func:`flask.jsonify`. This introduces a security risk in ancient
    browsers. See :ref:`json-security` for details.
-   Added before_render_template signal.
-   Added ``**kwargs`` to :meth:`flask.Test.test_client` to support
    passing additional keyword arguments to the constructor of
    :attr:`flask.Flask.test_client_class`.
-   Added ``SESSION_REFRESH_EACH_REQUEST`` config key that controls the
    set-cookie behavior. If set to ``True`` a permanent session will be
    refreshed each request and get their lifetime extended, if set to
    ``False`` it will only be modified if the session actually modifies.
    Non permanent sessions are not affected by this and will always
    expire if the browser window closes.
-   Made Flask support custom JSON mimetypes for incoming data.
-   Added support for returning tuples in the form ``(response,
    headers)`` from a view function.
-   Added :meth:`flask.Config.from_json`.
-   Added :attr:`flask.Flask.config_class`.
-   Added :meth:`flask.Config.get_namespace`.
-   Templates are no longer automatically reloaded outside of debug
    mode. This can be configured with the new ``TEMPLATES_AUTO_RELOAD``
    config key.
-   Added a workaround for a limitation in Python 3.3's namespace
    loader.
-   Added support for explicit root paths when using Python 3.3's
    namespace packages.
-   Added :command:`flask` and the ``flask.cli`` module to start the
    local debug server through the click CLI system. This is recommended
    over the old ``flask.run()`` method as it works faster and more
    reliable due to a different design and also replaces
    ``Flask-Script``.
-   Error handlers that match specific classes are now checked first,
    thereby allowing catching exceptions that are subclasses of HTTP
    exceptions (in ``werkzeug.exceptions``). This makes it possible for
    an extension author to create exceptions that will by default result
    in the HTTP error of their choosing, but may be caught with a custom
    error handler if desired.
-   Added :meth:`flask.Config.from_mapping`.
-   Flask will now log by default even if debug is disabled. The log
    format is now hardcoded but the default log handling can be disabled
    through the ``LOGGER_HANDLER_POLICY`` configuration key.
-   Removed deprecated module functionality.
-   Added the ``EXPLAIN_TEMPLATE_LOADING`` config flag which when
    enabled will instruct Flask to explain how it locates templates.
    This should help users debug when the wrong templates are loaded.
-   Enforce blueprint handling in the order they were registered for
    template loading.
-   Ported test suite to py.test.
-   Deprecated ``request.json`` in favour of ``request.get_json()``.
-   Add "pretty" and "compressed" separators definitions in jsonify()
    method. Reduces JSON response size when
    ``JSONIFY_PRETTYPRINT_REGULAR=False`` by removing unnecessary white
    space included by default after separators.
-   JSON responses are now terminated with a newline character, because
    it is a convention that UNIX text files end with a newline and some
    clients don't deal well when this newline is missing. This came up
    originally as a part of
    https://github.com/postmanlabs/httpbin/issues/168. :pr:`1262`
-   The automatically provided ``OPTIONS`` method is now correctly
    disabled if the user registered an overriding rule with the
    lowercase-version ``options``. :issue:`1288`
-   ``flask.json.jsonify`` now supports the ``datetime.date`` type.
    :pr:`1326`
-   Don't leak exception info of already caught exceptions to context
    teardown handlers. :pr:`1393`
-   Allow custom Jinja environment subclasses. :pr:`1422`
-   Updated extension dev guidelines.
-   ``flask.g`` now has ``pop()`` and ``setdefault`` methods.
-   Turn on autoescape for ``flask.templating.render_template_string``
    by default. :pr:`1515`
-   ``flask.ext`` is now deprecated. :pr:`1484`
-   ``send_from_directory`` now raises BadRequest if the filename is
    invalid on the server OS. :pr:`1763`
-   Added the ``JSONIFY_MIMETYPE`` configuration variable. :pr:`1728`
-   Exceptions during teardown handling will no longer leave bad
    application contexts lingering around.
-   Fixed broken ``test_appcontext_signals()`` test case.
-   Raise an :exc:`AttributeError` in :func:`flask.helpers.find_package`
    with a useful message explaining why it is raised when a PEP 302
    import hook is used without an ``is_package()`` method.
-   Fixed an issue causing exceptions raised before entering a request
    or app context to be passed to teardown handlers.
-   Fixed an issue with query parameters getting removed from requests
    in the test client when absolute URLs were requested.
-   Made ``@before_first_request`` into a decorator as intended.
-   Fixed an etags bug when sending a file streams with a name.
-   Fixed ``send_from_directory`` not expanding to the application root
    path correctly.
-   Changed logic of before first request handlers to flip the flag
    after invoking. This will allow some uses that are potentially
    dangerous but should probably be permitted.
-   Fixed Python 3 bug when a handler from
    ``app.url_build_error_handlers`` reraises the ``BuildError``.


Version 0.10.1
--------------

Released 2013-06-14

-   Fixed an issue where ``|tojson`` was not quoting single quotes which
    made the filter not work properly in HTML attributes. Now it's
    possible to use that filter in single quoted attributes. This should
    make using that filter with angular.js easier.
-   Added support for byte strings back to the session system. This
    broke compatibility with the common case of people putting binary
    data for token verification into the session.
-   Fixed an issue where registering the same method twice for the same
    endpoint would trigger an exception incorrectly.


Version 0.10
------------

Released 2013-06-13, codename Limoncello

-   Changed default cookie serialization format from pickle to JSON to
    limit the impact an attacker can do if the secret key leaks. See
    :ref:`upgrading-to-010` for more information.
-   Added ``template_test`` methods in addition to the already existing
    ``template_filter`` method family.
-   Added ``template_global`` methods in addition to the already
    existing ``template_filter`` method family.
-   Set the content-length header for x-sendfile.
-   ``tojson`` filter now does not escape script blocks in HTML5
    parsers.
-   ``tojson`` used in templates is now safe by default due. This was
    allowed due to the different escaping behavior.
-   Flask will now raise an error if you attempt to register a new
    function on an already used endpoint.
-   Added wrapper module around simplejson and added default
    serialization of datetime objects. This allows much easier
    customization of how JSON is handled by Flask or any Flask
    extension.
-   Removed deprecated internal ``flask.session`` module alias. Use
    ``flask.sessions`` instead to get the session module. This is not to
    be confused with ``flask.session`` the session proxy.
-   Templates can now be rendered without request context. The behavior
    is slightly different as the ``request``, ``session`` and ``g``
    objects will not be available and blueprint's context processors are
    not called.
-   The config object is now available to the template as a real global
    and not through a context processor which makes it available even in
    imported templates by default.
-   Added an option to generate non-ascii encoded JSON which should
    result in less bytes being transmitted over the network. It's
    disabled by default to not cause confusion with existing libraries
    that might expect ``flask.json.dumps`` to return bytestrings by
    default.
-   ``flask.g`` is now stored on the app context instead of the request
    context.
-   ``flask.g`` now gained a ``get()`` method for not erroring out on
    non existing items.
-   ``flask.g`` now can be used with the ``in`` operator to see what's
    defined and it now is iterable and will yield all attributes stored.
-   ``flask.Flask.request_globals_class`` got renamed to
    ``flask.Flask.app_ctx_globals_class`` which is a better name to what
    it does since 0.10.
-   ``request``, ``session`` and ``g`` are now also added as proxies to
    the template context which makes them available in imported
    templates. One has to be very careful with those though because
    usage outside of macros might cause caching.
-   Flask will no longer invoke the wrong error handlers if a proxy
    exception is passed through.
-   Added a workaround for chrome's cookies in localhost not working as
    intended with domain names.
-   Changed logic for picking defaults for cookie values from sessions
    to work better with Google Chrome.
-   Added ``message_flashed`` signal that simplifies flashing testing.
-   Added support for copying of request contexts for better working
    with greenlets.
-   Removed custom JSON HTTP exception subclasses. If you were relying
    on them you can reintroduce them again yourself trivially. Using
    them however is strongly discouraged as the interface was flawed.
-   Python requirements changed: requiring Python 2.6 or 2.7 now to
    prepare for Python 3.3 port.
-   Changed how the teardown system is informed about exceptions. This
    is now more reliable in case something handles an exception halfway
    through the error handling process.
-   Request context preservation in debug mode now keeps the exception
    information around which means that teardown handlers are able to
    distinguish error from success cases.
-   Added the ``JSONIFY_PRETTYPRINT_REGULAR`` configuration variable.
-   Flask now orders JSON keys by default to not trash HTTP caches due
    to different hash seeds between different workers.
-   Added ``appcontext_pushed`` and ``appcontext_popped`` signals.
-   The builtin run method now takes the ``SERVER_NAME`` into account
    when picking the default port to run on.
-   Added ``flask.request.get_json()`` as a replacement for the old
    ``flask.request.json`` property.


Version 0.9
-----------

Released 2012-07-01, codename Campari

-   The :func:`flask.Request.on_json_loading_failed` now returns a JSON
    formatted response by default.
-   The :func:`flask.url_for` function now can generate anchors to the
    generated links.
-   The :func:`flask.url_for` function now can also explicitly generate
    URL rules specific to a given HTTP method.
-   Logger now only returns the debug log setting if it was not set
    explicitly.
-   Unregister a circular dependency between the WSGI environment and
    the request object when shutting down the request. This means that
    environ ``werkzeug.request`` will be ``None`` after the response was
    returned to the WSGI server but has the advantage that the garbage
    collector is not needed on CPython to tear down the request unless
    the user created circular dependencies themselves.
-   Session is now stored after callbacks so that if the session payload
    is stored in the session you can still modify it in an after request
    callback.
-   The :class:`flask.Flask` class will avoid importing the provided
    import name if it can (the required first parameter), to benefit
    tools which build Flask instances programmatically. The Flask class
    will fall back to using import on systems with custom module hooks,
    e.g. Google App Engine, or when the import name is inside a zip
    archive (usually a .egg) prior to Python 2.7.
-   Blueprints now have a decorator to add custom template filters
    application wide, :meth:`flask.Blueprint.app_template_filter`.
-   The Flask and Blueprint classes now have a non-decorator method for
    adding custom template filters application wide,
    :meth:`flask.Flask.add_template_filter` and
    :meth:`flask.Blueprint.add_app_template_filter`.
-   The :func:`flask.get_flashed_messages` function now allows rendering
    flashed message categories in separate blocks, through a
    ``category_filter`` argument.
-   The :meth:`flask.Flask.run` method now accepts ``None`` for ``host``
    and ``port`` arguments, using default values when ``None``. This
    allows for calling run using configuration values, e.g.
    ``app.run(app.config.get('MYHOST'), app.config.get('MYPORT'))``,
    with proper behavior whether or not a config file is provided.
-   The :meth:`flask.render_template` method now accepts a either an
    iterable of template names or a single template name. Previously, it
    only accepted a single template name. On an iterable, the first
    template found is rendered.
-   Added :meth:`flask.Flask.app_context` which works very similar to
    the request context but only provides access to the current
    application. This also adds support for URL generation without an
    active request context.
-   View functions can now return a tuple with the first instance being
    an instance of :class:`flask.Response`. This allows for returning
    ``jsonify(error="error msg"), 400`` from a view function.
-   :class:`~flask.Flask` and :class:`~flask.Blueprint` now provide a
    :meth:`~flask.Flask.get_send_file_max_age` hook for subclasses to
    override behavior of serving static files from Flask when using
    :meth:`flask.Flask.send_static_file` (used for the default static
    file handler) and :func:`~flask.helpers.send_file`. This hook is
    provided a filename, which for example allows changing cache
    controls by file extension. The default max-age for ``send_file``
    and static files can be configured through a new
    ``SEND_FILE_MAX_AGE_DEFAULT`` configuration variable, which is used
    in the default ``get_send_file_max_age`` implementation.
-   Fixed an assumption in sessions implementation which could break
    message flashing on sessions implementations which use external
    storage.
-   Changed the behavior of tuple return values from functions. They are
    no longer arguments to the response object, they now have a defined
    meaning.
-   Added :attr:`flask.Flask.request_globals_class` to allow a specific
    class to be used on creation of the :data:`~flask.g` instance of
    each request.
-   Added ``required_methods`` attribute to view functions to force-add
    methods on registration.
-   Added :func:`flask.after_this_request`.
-   Added :func:`flask.stream_with_context` and the ability to push
    contexts multiple times without producing unexpected behavior.


Version 0.8.1
-------------

Released 2012-07-01

-   Fixed an issue with the undocumented ``flask.session`` module to not
    work properly on Python 2.5. It should not be used but did cause
    some problems for package managers.


Version 0.8
-----------

Released 2011-09-29, codename Rakija

-   Refactored session support into a session interface so that the
    implementation of the sessions can be changed without having to
    override the Flask class.
-   Empty session cookies are now deleted properly automatically.
-   View functions can now opt out of getting the automatic OPTIONS
    implementation.
-   HTTP exceptions and Bad Request errors can now be trapped so that
    they show up normally in the traceback.
-   Flask in debug mode is now detecting some common problems and tries
    to warn you about them.
-   Flask in debug mode will now complain with an assertion error if a
    view was attached after the first request was handled. This gives
    earlier feedback when users forget to import view code ahead of
    time.
-   Added the ability to register callbacks that are only triggered once
    at the beginning of the first request.
    (:meth:`Flask.before_first_request`)
-   Malformed JSON data will now trigger a bad request HTTP exception
    instead of a value error which usually would result in a 500
    internal server error if not handled. This is a backwards
    incompatible change.
-   Applications now not only have a root path where the resources and
    modules are located but also an instance path which is the
    designated place to drop files that are modified at runtime (uploads
    etc.). Also this is conceptually only instance depending and outside
    version control so it's the perfect place to put configuration files
    etc. For more information see :ref:`instance-folders`.
-   Added the ``APPLICATION_ROOT`` configuration variable.
-   Implemented :meth:`~flask.testing.TestClient.session_transaction` to
    easily modify sessions from the test environment.
-   Refactored test client internally. The ``APPLICATION_ROOT``
    configuration variable as well as ``SERVER_NAME`` are now properly
    used by the test client as defaults.
-   Added :attr:`flask.views.View.decorators` to support simpler
    decorating of pluggable (class-based) views.
-   Fixed an issue where the test client if used with the "with"
    statement did not trigger the execution of the teardown handlers.
-   Added finer control over the session cookie parameters.
-   HEAD requests to a method view now automatically dispatch to the
    ``get`` method if no handler was implemented.
-   Implemented the virtual :mod:`flask.ext` package to import
    extensions from.
-   The context preservation on exceptions is now an integral component
    of Flask itself and no longer of the test client. This cleaned up
    some internal logic and lowers the odds of runaway request contexts
    in unittests.
-   Fixed the Jinja2 environment's ``list_templates`` method not
    returning the correct names when blueprints or modules were
    involved.


Version 0.7.2
-------------

Released 2011-07-06

-   Fixed an issue with URL processors not properly working on
    blueprints.


Version 0.7.1
-------------

Released 2011-06-29

-   Added missing future import that broke 2.5 compatibility.
-   Fixed an infinite redirect issue with blueprints.


Version 0.7
-----------

Released 2011-06-28, codename Grappa

-   Added :meth:`~flask.Flask.make_default_options_response` which can
    be used by subclasses to alter the default behavior for ``OPTIONS``
    responses.
-   Unbound locals now raise a proper :exc:`RuntimeError` instead of an
    :exc:`AttributeError`.
-   Mimetype guessing and etag support based on file objects is now
    deprecated for :func:`flask.send_file` because it was unreliable.
    Pass filenames instead or attach your own etags and provide a proper
    mimetype by hand.
-   Static file handling for modules now requires the name of the static
    folder to be supplied explicitly. The previous autodetection was not
    reliable and caused issues on Google's App Engine. Until 1.0 the old
    behavior will continue to work but issue dependency warnings.
-   Fixed a problem for Flask to run on jython.
-   Added a ``PROPAGATE_EXCEPTIONS`` configuration variable that can be
    used to flip the setting of exception propagation which previously
    was linked to ``DEBUG`` alone and is now linked to either ``DEBUG``
    or ``TESTING``.
-   Flask no longer internally depends on rules being added through the
    ``add_url_rule`` function and can now also accept regular werkzeug
    rules added to the url map.
-   Added an ``endpoint`` method to the flask application object which
    allows one to register a callback to an arbitrary endpoint with a
    decorator.
-   Use Last-Modified for static file sending instead of Date which was
    incorrectly introduced in 0.6.
-   Added ``create_jinja_loader`` to override the loader creation
    process.
-   Implemented a silent flag for ``config.from_pyfile``.
-   Added ``teardown_request`` decorator, for functions that should run
    at the end of a request regardless of whether an exception occurred.
    Also the behavior for ``after_request`` was changed. It's now no
    longer executed when an exception is raised. See
    :ref:`upgrading-to-new-teardown-handling`
-   Implemented :func:`flask.has_request_context`
-   Deprecated ``init_jinja_globals``. Override the
    :meth:`~flask.Flask.create_jinja_environment` method instead to
    achieve the same functionality.
-   Added :func:`flask.safe_join`
-   The automatic JSON request data unpacking now looks at the charset
    mimetype parameter.
-   Don't modify the session on :func:`flask.get_flashed_messages` if
    there are no messages in the session.
-   ``before_request`` handlers are now able to abort requests with
    errors.
-   It is not possible to define user exception handlers. That way you
    can provide custom error messages from a central hub for certain
    errors that might occur during request processing (for instance
    database connection errors, timeouts from remote resources etc.).
-   Blueprints can provide blueprint specific error handlers.
-   Implemented generic :ref:`views` (class-based views).


Version 0.6.1
-------------

Released 2010-12-31

-   Fixed an issue where the default ``OPTIONS`` response was not
    exposing all valid methods in the ``Allow`` header.
-   Jinja2 template loading syntax now allows "./" in front of a
    template load path. Previously this caused issues with module
    setups.
-   Fixed an issue where the subdomain setting for modules was ignored
    for the static folder.
-   Fixed a security problem that allowed clients to download arbitrary
    files if the host server was a windows based operating system and
    the client uses backslashes to escape the directory the files where
    exposed from.


Version 0.6
-----------

Released 2010-07-27, codename Whisky

-   After request functions are now called in reverse order of
    registration.
-   OPTIONS is now automatically implemented by Flask unless the
    application explicitly adds 'OPTIONS' as method to the URL rule. In
    this case no automatic OPTIONS handling kicks in.
-   Static rules are now even in place if there is no static folder for
    the module. This was implemented to aid GAE which will remove the
    static folder if it's part of a mapping in the .yml file.
-   The :attr:`~flask.Flask.config` is now available in the templates as
    ``config``.
-   Context processors will no longer override values passed directly to
    the render function.
-   Added the ability to limit the incoming request data with the new
    ``MAX_CONTENT_LENGTH`` configuration value.
-   The endpoint for the :meth:`flask.Module.add_url_rule` method is now
    optional to be consistent with the function of the same name on the
    application object.
-   Added a :func:`flask.make_response` function that simplifies
    creating response object instances in views.
-   Added signalling support based on blinker. This feature is currently
    optional and supposed to be used by extensions and applications. If
    you want to use it, make sure to have `blinker`_ installed.
-   Refactored the way URL adapters are created. This process is now
    fully customizable with the :meth:`~flask.Flask.create_url_adapter`
    method.
-   Modules can now register for a subdomain instead of just an URL
    prefix. This makes it possible to bind a whole module to a
    configurable subdomain.

.. _blinker: https://pypi.org/project/blinker/


Version 0.5.2
-------------

Released 2010-07-15

-   Fixed another issue with loading templates from directories when
    modules were used.


Version 0.5.1
-------------

Released 2010-07-06

-   Fixes an issue with template loading from directories when modules
    where used.


Version 0.5
-----------

Released 2010-07-06, codename Calvados

-   Fixed a bug with subdomains that was caused by the inability to
    specify the server name. The server name can now be set with the
    ``SERVER_NAME`` config key. This key is now also used to set the
    session cookie cross-subdomain wide.
-   Autoescaping is no longer active for all templates. Instead it is
    only active for ``.html``, ``.htm``, ``.xml`` and ``.xhtml``. Inside
    templates this behavior can be changed with the ``autoescape`` tag.
-   Refactored Flask internally. It now consists of more than a single
    file.
-   :func:`flask.send_file` now emits etags and has the ability to do
    conditional responses builtin.
-   (temporarily) dropped support for zipped applications. This was a
    rarely used feature and led to some confusing behavior.
-   Added support for per-package template and static-file directories.
-   Removed support for ``create_jinja_loader`` which is no longer used
    in 0.5 due to the improved module support.
-   Added a helper function to expose files from any directory.


Version 0.4
-----------

Released 2010-06-18, codename Rakia

-   Added the ability to register application wide error handlers from
    modules.
-   :meth:`~flask.Flask.after_request` handlers are now also invoked if
    the request dies with an exception and an error handling page kicks
    in.
-   Test client has not the ability to preserve the request context for
    a little longer. This can also be used to trigger custom requests
    that do not pop the request stack for testing.
-   Because the Python standard library caches loggers, the name of the
    logger is configurable now to better support unittests.
-   Added ``TESTING`` switch that can activate unittesting helpers.
-   The logger switches to ``DEBUG`` mode now if debug is enabled.


Version 0.3.1
-------------

Released 2010-05-28

-   Fixed a error reporting bug with :meth:`flask.Config.from_envvar`
-   Removed some unused code from flask
-   Release does no longer include development leftover files (.git
    folder for themes, built documentation in zip and pdf file and some
    .pyc files)


Version 0.3
-----------

Released 2010-05-28, codename Schnaps

-   Added support for categories for flashed messages.
-   The application now configures a :class:`logging.Handler` and will
    log request handling exceptions to that logger when not in debug
    mode. This makes it possible to receive mails on server errors for
    example.
-   Added support for context binding that does not require the use of
    the with statement for playing in the console.
-   The request context is now available within the with statement
    making it possible to further push the request context or pop it.
-   Added support for configurations.


Version 0.2
-----------

Released 2010-05-12, codename Jägermeister

-   Various bugfixes
-   Integrated JSON support
-   Added :func:`~flask.get_template_attribute` helper function.
-   :meth:`~flask.Flask.add_url_rule` can now also register a view
    function.
-   Refactored internal request dispatching.
-   Server listens on 127.0.0.1 by default now to fix issues with
    chrome.
-   Added external URL support.
-   Added support for :func:`~flask.send_file`
-   Module support and internal request handling refactoring to better
    support pluggable applications.
-   Sessions can be set to be permanent now on a per-session basis.
-   Better error reporting on missing secret keys.
-   Added support for Google Appengine.


Version 0.1
-----------

Released 2010-04-16

-   First public preview release.