Changelog

Version 1.1.2

Unreleased

  • Work around an issue when running the flask command with anexternal debugger on Windows. #3297

Version 1.1.1

Released 2019-07-08

  • The flask.json_available flag was added back for compatibilitywith some extensions. It will raise a deprecation warning when used,and will be removed in version 2.0.0. #3288

Version 1.1.0

Released 2019-07-04

  • Bump minimum Werkzeug version to >= 0.15.

  • Drop support for Python 3.4.

  • Error handlers for InternalServerError or 500 will always bepassed an instance of InternalServerError. If they are invokeddue to an unhandled exception, that original exception is nowavailable as e.original_exception rather than being passeddirectly to the handler. The same is true if the handler is for thebase HTTPException. This makes error handler behavior moreconsistent. #3266

    • Flask.finalize_request() is called for all unhandledexceptions even if there is no 500 error handler.

  • Flask.logger takes the same name asFlask.name (the value passed asFlask(import_name). This reverts 1.0’s behavior of alwayslogging to "flask.app", in order to support multiple apps in thesame process. A warning will be shown if old configuration isdetected that needs to be moved. #2866

  • flask.RequestContext.copy() includes the current sessionobject in the request context copy. This prevents sessionpointing to an out-of-date object. #2935

  • Using built-in RequestContext, unprintable Unicode characters inHost header will result in a HTTP 400 response and not HTTP 500 aspreviously. #2994

  • send_file() supports PathLike objects asdescribed in PEP 0519, to support pathlib in Python 3.#3059

  • send_file() supports BytesIO partial content.#2957

  • open_resource() accepts the “rt” file mode. This still doesthe same thing as “r”. #3163

  • The MethodView.methods attribute set in a base class is usedby subclasses. #3138

  • Flask.jinja_options is a dict instead of anImmutableDict to allow easier configuration. Changes must stillbe made before creating the environment. #3190

  • Flask’s JSONMixin for the request and response wrappers wasmoved into Werkzeug. Use Werkzeug’s version with Flask-specificsupport. This bumps the Werkzeug dependency to >= 0.15.#3125

  • The flask command entry point is simplified to take advantageof Werkzeug 0.15’s better reloader support. This bumps the Werkzeugdependency to >= 0.15. #3022

  • Support static_url_path that ends with a forward slash.#3134

  • Support empty static_folder without requiring setting an emptystatic_url_path as well. #3124

  • jsonify() supports dataclasses.dataclass objects.#3195

  • Allow customizing the Flask.url_map_class used for routing.#3069

  • The development server port can be set to 0, which tells the OS topick an available port. #2926

  • The return value from cli.load_dotenv() is more consistentwith the documentation. It will return False if python-dotenv isnot installed, or if the given path isn’t a file. #2937

  • Signaling support has a stub for the connect_via method whenthe Blinker library is not installed. #3208

  • Add an —extra-files option to the flask run CLI command tospecify extra files that will trigger the reloader on change.#2897

  • Allow returning a dictionary from a view function. Similar to howreturning a string will produce a text/html response, returninga dict will call jsonify to produce a application/jsonresponse. #3111

  • Blueprints have a cli Click group like app.cli. CLI commandsregistered with a blueprint will be available as a group under theflask command. #1357.

  • When using the test client as a context manager (with client:),all preserved request contexts are popped when the block exits,ensuring nested contexts are cleaned up correctly. #3157

  • Show a better error message when the view return type is notsupported. #3214

  • flask.testing.make_test_environ_builder() has been deprecated infavour of a new class flask.testing.EnvironBuilder. #3232

  • The flask run command no longer fails if Python is not builtwith SSL support. Using the —cert option will show anappropriate error message. #3211

  • URL matching now occurs after the request context is pushed, ratherthan when it’s created. This allows custom URL converters to accessthe app and request contexts, such as to query a database for an id.#3088

Version 1.0.4

Released 2019-07-04

  • The key information for BadRequestKeyError is no longer clearedoutside debug mode, so error handlers can still access it. Thisrequires upgrading to Werkzeug 0.15.5. #3249

  • send_file url quotes the “:” and “/” characters for morecompatible UTF-8 filename support in some browsers. #3074

  • Fixes for PEP451 import loaders and pytest 5.x. #3275

  • Show message about dotenv on stderr instead of stdout. #3285

Version 1.0.3

Released 2019-05-17

  • send_file() encodes filenames as ASCII instead of Latin-1(ISO-8859-1). This fixes compatibility with Gunicorn, which isstricter about header encodings than PEP 3333. #2766

  • Allow custom CLIs using FlaskGroup to set the debug flag withoutit always being overwritten based on environment variables.#2765

  • flask —version outputs Werkzeug’s version and simplifies thePython version. #2825

  • send_file() handles an attachment_filename that is anative Python 2 string (bytes) with UTF-8 coded bytes. #2933

  • A catch-all error handler registered for HTTPException will nothandle RoutingException, which is used internally duringrouting. This fixes the unexpected behavior that had been introducedin 1.0. #2986

  • Passing the json argument to app.test_client does notpush/pop an extra app context. #2900

Version 1.0.2

Released 2018-05-02

  • Fix more backwards compatibility issues with merging slashes betweena blueprint prefix and route. #2748

  • Fix error with flask routes command when there are no routes.#2751

Version 1.0.1

Released 2018-04-29

  • Fix registering partials (with no name) as view functions.#2730

  • Don’t treat lists returned from view functions the same as tuples.Only tuples are interpreted as response data. #2736

  • Extra slashes between a blueprint’s url_prefix and a route URLare merged. This fixes some backwards compatibility issues with thechange in 1.0. #2731, #2742

  • Only trap BadRequestKeyError errors in debug mode, not allBadRequest errors. This allows abort(400) to continueworking as expected. #2735

  • The FLASK_SKIP_DOTENV environment variable can be set to 1to skip automatically loading dotenv files. #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.#2586

  • Skip app.run when a Flask application is runfrom the command line. This avoids some behavior that was confusingto debug.

  • Change the default for JSONIFY_PRETTYPRINT_REGULAR toFalse. jsonify() returns a compact format bydefault, and an indented format in debug mode. #2193

  • Flask.init accepts the host_matchingargument and sets it on url_map. #1559

  • Flask.init accepts the static_host argumentand passes it as the host argument when defining the staticroute. #1559

  • send_file() supports Unicode in attachment_filename.#2223

  • Pass _scheme argument from url_for() tohandle_url_build_error(). #2017

  • add_url_rule() accepts theprovide_automatic_options argument to disable adding theOPTIONS method. #1489

  • MethodView subclasses inherit method handlers frombase classes. #1936

  • Errors caused while opening the session at the beginning of therequest are handled by the app’s error handlers. #2254

  • Blueprints gained json_encoder andjson_decoder attributes to override the app’sencoder and decoder. #1898

  • Flask.make_response() raises TypeError instead ofValueError for bad response types. The error messages have beenimproved to describe why the type is invalid. #2256

  • Add routes CLI command to output routes registered on theapplication. #2259

  • Show warning when session cookie domain is a bare hostname or an IPaddress, as these may not behave properly in some browsers, such asChrome. #2282

  • Allow IP address as exact session cookie domain. #2282

  • SESSION_COOKIE_DOMAIN is set if it is detected throughSERVER_NAME. #2282

  • Auto-detect zero-argument app factory called create_app ormake_app from FLASK_APP. #2297

  • Factory functions are not required to take a script_infoparameter to work with the flask command. If they take a singleparameter or a parameter named script_info, theScriptInfo object will be passed. #2319

  • FLASK_APP can be set to an app factory, with arguments ifneeded, for example FLASK_APP=myproject.app:create_app('dev').#2326

  • FLASK_APP can point to local packages that are not installed ineditable mode, although pip install -e is still preferred.#2414

  • The View class attributeprovide_automatic_options is set inas_view(), to be detected byadd_url_rule(). #2316

  • Error handling will try handlers registered for blueprint, code,app, code, blueprint, exception, app, exception.#2314

  • Cookie is added to the response’s Vary header if the sessionis accessed at all during the request (and not deleted). #2288

  • test_request_context() accepts subdomain andurl_scheme arguments for use when building the base URL.#1621

  • Set APPLICATION_ROOT to '/' by default. This was alreadythe implicit default when it was set to None.

  • TRAP_BAD_REQUEST_ERRORS is enabled by default in debug mode.BadRequestKeyError has a message with the bad key in debug modeinstead of the generic bad request message. #2348

  • Allow registering new tags withTaggedJSONSerializer to support storing othertypes in the session cookie. #2352

  • Only open the session if the request has not been pushed onto thecontext stack yet. This allows stream_with_context()generators to access the same session that the containing view uses.#2354

  • Add json keyword argument for the test client request methods.This will dump the given object as JSON and set the appropriatecontent type. #2358

  • Extract JSON handling to a mixin applied to both theRequest and Response classes. This adds theis_json() and get_json() methods tothe response to make testing JSON response much easier. #2358

  • Removed error handler caching because it caused unexpected resultsfor some exception inheritance hierarchies. Register handlersexplicitly for each exception if you want to avoid traversing theMRO. #2362

  • Fix incorrect JSON encoding of aware, non-UTC datetimes. #2374

  • Template auto reloading will honor debug mode even even ifjinja_env was already accessed. #2373

  • The following old deprecated code was removed. #2385

  • The Request.json property is no longer deprecated.#1421

  • Support passing a EnvironBuilder or dictto test_client.open. #2412

  • The flask command and Flask.run() will load environmentvariables from .env and .flaskenv files if python-dotenv isinstalled. #2416

  • When passing a full URL to the test client, the scheme in the URL isused instead of PREFERRED_URL_SCHEME. #2430

  • Flask.logger has been simplified. LOGGER_NAME andLOGGER_HANDLER_POLICY config was removed. The logger is alwaysnamed flask.app. The level is only set on first access, itdoesn’t check Flask.debug each time. Only one format isused, not different ones depending on Flask.debug. Nohandlers are removed, and a handler is only added if no handlers arealready configured. #2436

  • Blueprint view function names may not contain dots. #2450

  • Fix a ValueError caused by invalid Range requests in somecases. #2526

  • The development server uses threads by default. #2529

  • Loading config files with silent=True will ignoreENOTDIR errors. #2581

  • Pass —cert and —key options to flask run to run thedevelopment server over HTTPS. #2606

  • Added SESSION_COOKIE_SAMESITE to control the SameSiteattribute on the session cookie. #2607

  • Added test_cli_runner() to create a Click runnerthat can invoke Flask CLI commands for testing. #2636

  • Subdomain matching is disabled by default and settingSERVER_NAME does not implicitly enable it. It can be enabledby passing subdomain_matching=True to the Flask constructor.#2635

  • A single trailing slash is stripped from the blueprinturl_prefix when it is registered with the app. #2629

  • Request.get_json() doesn’t cache the result if parsing failswhen silent is true. #2651

  • Request.get_json() no longer accepts arbitrary encodings.Incoming JSON should be encoded using UTF-8 per RFC 8259, butFlask will autodetect UTF-8, -16, or -32. #2691

  • Added MAX_COOKIE_SIZE and Response.max_cookie_sizeto control when Werkzeug warns about large cookies that browsers mayignore. #2693

  • Updated documentation theme to make docs look better in smallwindows. #2709

  • Rewrote the tutorial docs and example project to take a morestructured approach to help new users avoid common pitfalls.#2676

Version 0.12.4

Released 2018-04-29

  • Repackage 0.12.3 to fix package layout issue. #2728

Version 0.12.3

Released 2018-04-26

  • Request.get_json() no longer accepts arbitrary encodings.Incoming JSON should be encoded using UTF-8 per RFC 8259, butFlask will autodetect UTF-8, -16, or -32. #2692

  • Fix a Python warning about imports when using python -m flask.#2666

  • Fix a ValueError caused by invalid Range requests in somecases.

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 anImportError occurs within the imported application module.

  • Fix encoding behavior of app.config.from_pyfile for Python 3.#2118

  • Use the SERVER_NAME config if it is present as default valuesfor app.run. #2109, #2152

  • Call ctx.auto_pop with the exception object instead of None,in the event that a BaseException such as KeyboardInterruptis 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 insend_file has been removed. #104, :pr1849

  • Mimetype guessing in send_file now fails loudly and doesn’t fallback to application/octet-stream. #1988

  • Make flask.safe_join able to join multiple paths likeos.path.join #1730

  • Revert a behavior change that made the dev server crash instead ofreturning an Internal Server Error. #2006

  • Correctly invoke response handlers for both regular requestdispatching 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 cannow be directly set, instead of per client.get.

  • Fix crash when running under PyPy3. #1814

Version 0.11.1

Released 2016-06-07

  • Fixed a bug that prevented FLASKAPP=foobar/_init.py fromworking. #1872

Version 0.11

Released 2016-05-29, codename Absinthe

  • Added support to serializing top-level arrays toflask.jsonify(). This introduces a security risk in ancientbrowsers. See JSON Security for details.

  • Added before_render_template signal.

  • Added **kwargs to flask.Test.test_client() to supportpassing additional keyword arguments to the constructor offlask.Flask.test_client_class.

  • Added SESSION_REFRESH_EACH_REQUEST config key that controls theset-cookie behavior. If set to True a permanent session will berefreshed each request and get their lifetime extended, if set toFalse it will only be modified if the session actually modifies.Non permanent sessions are not affected by this and will alwaysexpire 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 flask.Config.from_json().

  • Added flask.Flask.config_class.

  • Added flask.Config.get_namespace().

  • Templates are no longer automatically reloaded outside of debugmode. This can be configured with the new TEMPLATES_AUTO_RELOADconfig key.

  • Added a workaround for a limitation in Python 3.3’s namespaceloader.

  • Added support for explicit root paths when using Python 3.3’snamespace packages.

  • Added flask and the flask.cli module to start thelocal debug server through the click CLI system. This is recommendedover the old flask.run() method as it works faster and morereliable due to a different design and also replacesFlask-Script.

  • Error handlers that match specific classes are now checked first,thereby allowing catching exceptions that are subclasses of HTTPexceptions (in werkzeug.exceptions). This makes it possible foran extension author to create exceptions that will by default resultin the HTTP error of their choosing, but may be caught with a customerror handler if desired.

  • Added flask.Config.from_mapping().

  • Flask will now log by default even if debug is disabled. The logformat is now hardcoded but the default log handling can be disabledthrough the LOGGER_HANDLER_POLICY configuration key.

  • Removed deprecated module functionality.

  • Added the EXPLAIN_TEMPLATE_LOADING config flag which whenenabled 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 fortemplate 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 whenJSONIFY_PRETTYPRINT_REGULAR=False by removing unnecessary whitespace included by default after separators.

  • JSON responses are now terminated with a newline character, becauseit is a convention that UNIX text files end with a newline and someclients don’t deal well when this newline is missing. This came uporiginally as a part ofhttps://github.com/postmanlabs/httpbin/issues/168. #1262

  • The automatically provided OPTIONS method is now correctlydisabled if the user registered an overriding rule with thelowercase-version options. #1288

  • flask.json.jsonify now supports the datetime.date type.#1326

  • Don’t leak exception info of already caught exceptions to contextteardown handlers. #1393

  • Allow custom Jinja environment subclasses. #1422

  • Updated extension dev guidelines.

  • flask.g now has pop() and setdefault methods.

  • Turn on autoescape for flask.templating.render_template_stringby default. #1515

  • flask.ext is now deprecated. #1484

  • send_from_directory now raises BadRequest if the filename isinvalid on the server OS. #1763

  • Added the JSONIFY_MIMETYPE configuration variable. #1728

  • Exceptions during teardown handling will no longer leave badapplication contexts lingering around.

  • Fixed broken test_appcontext_signals() test case.

  • Raise an AttributeError in flask.helpers.find_package()with a useful message explaining why it is raised when a PEP 302import hook is used without an is_package() method.

  • Fixed an issue causing exceptions raised before entering a requestor app context to be passed to teardown handlers.

  • Fixed an issue with query parameters getting removed from requestsin 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 rootpath correctly.

  • Changed logic of before first request handlers to flip the flagafter invoking. This will allow some uses that are potentiallydangerous but should probably be permitted.

  • Fixed Python 3 bug when a handler fromapp.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 whichmade the filter not work properly in HTML attributes. Now it’spossible to use that filter in single quoted attributes. This shouldmake using that filter with angular.js easier.

  • Added support for byte strings back to the session system. Thisbroke compatibility with the common case of people putting binarydata for token verification into the session.

  • Fixed an issue where registering the same method twice for the sameendpoint would trigger an exception incorrectly.

Version 0.10

Released 2013-06-13, codename Limoncello

  • Changed default cookie serialization format from pickle to JSON tolimit the impact an attacker can do if the secret key leaks. SeeVersion 0.10 for more information.

  • Added template_test methods in addition to the already existingtemplate_filter method family.

  • Added template_global methods in addition to the alreadyexisting template_filter method family.

  • Set the content-length header for x-sendfile.

  • tojson filter now does not escape script blocks in HTML5parsers.

  • tojson used in templates is now safe by default due. This wasallowed due to the different escaping behavior.

  • Flask will now raise an error if you attempt to register a newfunction on an already used endpoint.

  • Added wrapper module around simplejson and added defaultserialization of datetime objects. This allows much easiercustomization of how JSON is handled by Flask or any Flaskextension.

  • Removed deprecated internal flask.session module alias. Useflask.sessions instead to get the session module. This is not tobe confused with flask.session the session proxy.

  • Templates can now be rendered without request context. The behavioris slightly different as the request, session and gobjects will not be available and blueprint’s context processors arenot called.

  • The config object is now available to the template as a real globaland not through a context processor which makes it available even inimported templates by default.

  • Added an option to generate non-ascii encoded JSON which shouldresult in less bytes being transmitted over the network. It’sdisabled by default to not cause confusion with existing librariesthat might expect flask.json.dumps to return bytestrings bydefault.

  • flask.g is now stored on the app context instead of the requestcontext.

  • flask.g now gained a get() method for not erroring out onnon existing items.

  • flask.g now can be used with the in operator to see what’sdefined and it now is iterable and will yield all attributes stored.

  • flask.Flask.request_globals_class got renamed toflask.Flask.app_ctx_globals_class which is a better name to whatit does since 0.10.

  • request, session and g are now also added as proxies tothe template context which makes them available in importedtemplates. One has to be very careful with those though becauseusage outside of macros might cause caching.

  • Flask will no longer invoke the wrong error handlers if a proxyexception is passed through.

  • Added a workaround for chrome’s cookies in localhost not working asintended with domain names.

  • Changed logic for picking defaults for cookie values from sessionsto work better with Google Chrome.

  • Added message_flashed signal that simplifies flashing testing.

  • Added support for copying of request contexts for better workingwith greenlets.

  • Removed custom JSON HTTP exception subclasses. If you were relyingon them you can reintroduce them again yourself trivially. Usingthem however is strongly discouraged as the interface was flawed.

  • Python requirements changed: requiring Python 2.6 or 2.7 now toprepare for Python 3.3 port.

  • Changed how the teardown system is informed about exceptions. Thisis now more reliable in case something handles an exception halfwaythrough the error handling process.

  • Request context preservation in debug mode now keeps the exceptioninformation around which means that teardown handlers are able todistinguish error from success cases.

  • Added the JSONIFY_PRETTYPRINT_REGULAR configuration variable.

  • Flask now orders JSON keys by default to not trash HTTP caches dueto different hash seeds between different workers.

  • Added appcontext_pushed and appcontext_popped signals.

  • The builtin run method now takes the SERVER_NAME into accountwhen picking the default port to run on.

  • Added flask.request.get_json() as a replacement for the oldflask.request.json property.

Version 0.9

Released 2012-07-01, codename Campari

  • The flask.Request.on_json_loading_failed() now returns a JSONformatted response by default.

  • The flask.url_for() function now can generate anchors to thegenerated links.

  • The flask.url_for() function now can also explicitly generateURL rules specific to a given HTTP method.

  • Logger now only returns the debug log setting if it was not setexplicitly.

  • Unregister a circular dependency between the WSGI environment andthe request object when shutting down the request. This means thatenviron werkzeug.request will be None after the response wasreturned to the WSGI server but has the advantage that the garbagecollector is not needed on CPython to tear down the request unlessthe user created circular dependencies themselves.

  • Session is now stored after callbacks so that if the session payloadis stored in the session you can still modify it in an after requestcallback.

  • The flask.Flask class will avoid importing the providedimport name if it can (the required first parameter), to benefittools which build Flask instances programmatically. The Flask classwill fall back to using import on systems with custom module hooks,e.g. Google App Engine, or when the import name is inside a ziparchive (usually a .egg) prior to Python 2.7.

  • Blueprints now have a decorator to add custom template filtersapplication wide, flask.Blueprint.app_template_filter().

  • The Flask and Blueprint classes now have a non-decorator method foradding custom template filters application wide,flask.Flask.add_template_filter() andflask.Blueprint.add_app_template_filter().

  • The flask.get_flashed_messages() function now allows renderingflashed message categories in separate blocks, through acategory_filter argument.

  • The flask.Flask.run() method now accepts None for hostand port arguments, using default values when None. Thisallows 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 flask.render_template() method now accepts a either aniterable of template names or a single template name. Previously, itonly accepted a single template name. On an iterable, the firsttemplate found is rendered.

  • Added flask.Flask.app_context() which works very similar tothe request context but only provides access to the currentapplication. This also adds support for URL generation without anactive request context.

  • View functions can now return a tuple with the first instance beingan instance of flask.Response. This allows for returningjsonify(error="error msg"), 400 from a view function.

  • Flask and Blueprint now provide aget_send_file_max_age() hook for subclasses tooverride behavior of serving static files from Flask when usingflask.Flask.send_static_file() (used for the default staticfile handler) and send_file(). This hook isprovided a filename, which for example allows changing cachecontrols by file extension. The default max-age for send_fileand static files can be configured through a newSEND_FILE_MAX_AGE_DEFAULT configuration variable, which is usedin the default get_send_file_max_age implementation.

  • Fixed an assumption in sessions implementation which could breakmessage flashing on sessions implementations which use externalstorage.

  • Changed the behavior of tuple return values from functions. They areno longer arguments to the response object, they now have a definedmeaning.

  • Added flask.Flask.request_globals_class to allow a specificclass to be used on creation of the g instance ofeach request.

  • Added required_methods attribute to view functions to force-addmethods on registration.

  • Added flask.after_this_request().

  • Added flask.stream_with_context() and the ability to pushcontexts multiple times without producing unexpected behavior.

Version 0.8.1

Released 2012-07-01

  • Fixed an issue with the undocumented flask.session module to notwork properly on Python 2.5. It should not be used but did causesome problems for package managers.

Version 0.8

Released 2011-09-29, codename Rakija

  • Refactored session support into a session interface so that theimplementation of the sessions can be changed without having tooverride the Flask class.

  • Empty session cookies are now deleted properly automatically.

  • View functions can now opt out of getting the automatic OPTIONSimplementation.

  • HTTP exceptions and Bad Request errors can now be trapped so thatthey show up normally in the traceback.

  • Flask in debug mode is now detecting some common problems and triesto warn you about them.

  • Flask in debug mode will now complain with an assertion error if aview was attached after the first request was handled. This givesearlier feedback when users forget to import view code ahead oftime.

  • Added the ability to register callbacks that are only triggered onceat the beginning of the first request.(Flask.before_first_request())

  • Malformed JSON data will now trigger a bad request HTTP exceptioninstead of a value error which usually would result in a 500internal server error if not handled. This is a backwardsincompatible change.

  • Applications now not only have a root path where the resources andmodules are located but also an instance path which is thedesignated place to drop files that are modified at runtime (uploadsetc.). Also this is conceptually only instance depending and outsideversion control so it’s the perfect place to put configuration filesetc. For more information see Instance Folders.

  • Added the APPLICATION_ROOT configuration variable.

  • Implemented session_transaction() toeasily modify sessions from the test environment.

  • Refactored test client internally. The APPLICATION_ROOTconfiguration variable as well as SERVER_NAME are now properlyused by the test client as defaults.

  • Added flask.views.View.decorators to support simplerdecorating 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 theget method if no handler was implemented.

  • Implemented the virtual flask.ext package to importextensions from.

  • The context preservation on exceptions is now an integral componentof Flask itself and no longer of the test client. This cleaned upsome internal logic and lowers the odds of runaway request contextsin unittests.

  • Fixed the Jinja2 environment’s list_templates method notreturning the correct names when blueprints or modules wereinvolved.

Version 0.7.2

Released 2011-07-06

  • Fixed an issue with URL processors not properly working onblueprints.

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 make_default_options_response() which canbe used by subclasses to alter the default behavior for OPTIONSresponses.

  • Unbound locals now raise a proper RuntimeError instead of anAttributeError.

  • Mimetype guessing and etag support based on file objects is nowdeprecated for flask.send_file() because it was unreliable.Pass filenames instead or attach your own etags and provide a propermimetype by hand.

  • Static file handling for modules now requires the name of the staticfolder to be supplied explicitly. The previous autodetection was notreliable and caused issues on Google’s App Engine. Until 1.0 the oldbehavior 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 beused to flip the setting of exception propagation which previouslywas linked to DEBUG alone and is now linked to either DEBUGor TESTING.

  • Flask no longer internally depends on rules being added through theadd_url_rule function and can now also accept regular werkzeugrules added to the url map.

  • Added an endpoint method to the flask application object whichallows one to register a callback to an arbitrary endpoint with adecorator.

  • Use Last-Modified for static file sending instead of Date which wasincorrectly introduced in 0.6.

  • Added create_jinja_loader to override the loader creationprocess.

  • Implemented a silent flag for config.from_pyfile.

  • Added teardown_request decorator, for functions that should runat the end of a request regardless of whether an exception occurred.Also the behavior for after_request was changed. It’s now nolonger executed when an exception is raised. SeeUpgrading to new Teardown Handling

  • Implemented flask.has_request_context()

  • Deprecated init_jinja_globals. Override thecreate_jinja_environment() method instead toachieve the same functionality.

  • Added flask.safe_join()

  • The automatic JSON request data unpacking now looks at the charsetmimetype parameter.

  • Don’t modify the session on flask.get_flashed_messages() ifthere are no messages in the session.

  • before_request handlers are now able to abort requests witherrors.

  • It is not possible to define user exception handlers. That way youcan provide custom error messages from a central hub for certainerrors that might occur during request processing (for instancedatabase connection errors, timeouts from remote resources etc.).

  • Blueprints can provide blueprint specific error handlers.

  • Implemented generic Pluggable Views (class-based views).

Version 0.6.1

Released 2010-12-31

  • Fixed an issue where the default OPTIONS response was notexposing all valid methods in the Allow header.

  • Jinja2 template loading syntax now allows “./” in front of atemplate load path. Previously this caused issues with modulesetups.

  • Fixed an issue where the subdomain setting for modules was ignoredfor the static folder.

  • Fixed a security problem that allowed clients to download arbitraryfiles if the host server was a windows based operating system andthe client uses backslashes to escape the directory the files whereexposed from.

Version 0.6

Released 2010-07-27, codename Whisky

  • After request functions are now called in reverse order ofregistration.

  • OPTIONS is now automatically implemented by Flask unless theapplication explicitly adds ‘OPTIONS’ as method to the URL rule. Inthis case no automatic OPTIONS handling kicks in.

  • Static rules are now even in place if there is no static folder forthe module. This was implemented to aid GAE which will remove thestatic folder if it’s part of a mapping in the .yml file.

  • The config is now available in the templates asconfig.

  • Context processors will no longer override values passed directly tothe render function.

  • Added the ability to limit the incoming request data with the newMAX_CONTENT_LENGTH configuration value.

  • The endpoint for the flask.Module.add_url_rule() method is nowoptional to be consistent with the function of the same name on theapplication object.

  • Added a flask.make_response() function that simplifiescreating response object instances in views.

  • Added signalling support based on blinker. This feature is currentlyoptional and supposed to be used by extensions and applications. Ifyou want to use it, make sure to have blinker installed.

  • Refactored the way URL adapters are created. This process is nowfully customizable with the create_url_adapter()method.

  • Modules can now register for a subdomain instead of just an URLprefix. This makes it possible to bind a whole module to aconfigurable subdomain.

Version 0.5.2

Released 2010-07-15

  • Fixed another issue with loading templates from directories whenmodules were used.

Version 0.5.1

Released 2010-07-06

  • Fixes an issue with template loading from directories when moduleswhere used.

Version 0.5

Released 2010-07-06, codename Calvados

  • Fixed a bug with subdomains that was caused by the inability tospecify the server name. The server name can now be set with theSERVER_NAME config key. This key is now also used to set thesession cookie cross-subdomain wide.

  • Autoescaping is no longer active for all templates. Instead it isonly active for .html, .htm, .xml and .xhtml. Insidetemplates this behavior can be changed with the autoescape tag.

  • Refactored Flask internally. It now consists of more than a singlefile.

  • flask.send_file() now emits etags and has the ability to doconditional responses builtin.

  • (temporarily) dropped support for zipped applications. This was ararely 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 usedin 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 frommodules.

  • after_request() handlers are now also invoked ifthe request dies with an exception and an error handling page kicksin.

  • Test client has not the ability to preserve the request context fora little longer. This can also be used to trigger custom requeststhat do not pop the request stack for testing.

  • Because the Python standard library caches loggers, the name of thelogger 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 flask.Config.from_envvar()

  • Removed some unused code from flask

  • Release does no longer include development leftover files (.gitfolder 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 logging.Handler and willlog request handling exceptions to that logger when not in debugmode. This makes it possible to receive mails on server errors forexample.

  • Added support for context binding that does not require the use ofthe with statement for playing in the console.

  • The request context is now available within the with statementmaking it possible to further push the request context or pop it.

  • Added support for configurations.

Version 0.2

Released 2010-05-12, codename J?germeister

  • Various bugfixes

  • Integrated JSON support

  • Added get_template_attribute() helper function.

  • add_url_rule() can now also register a viewfunction.

  • Refactored internal request dispatching.

  • Server listens on 127.0.0.1 by default now to fix issues withchrome.

  • Added external URL support.

  • Added support for send_file()

  • Module support and internal request handling refactoring to bettersupport 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.