Changelog - webargs 8.7.1 documentation

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# Changelog

## 8.7.1 (unreleased)

Bug fixes:

- Correct the package metadata for `marshmallow` versions which are supported by `webargs`

- Fix deprecation warning on Python 3.14 (#1013). Thanks @decaz for reporting and for the PR.

Other changes:

- Test against Python 3.14 (#1016).

## 8.7.0 (2025-04-18)

Other changes:

- Test against Python 3.13 (#982).

- Drop support for Python 3.8, which is EOL (#981).

- Support marshmallow 4 (#987).

## 8.6.0 (2024-09-11)

Bug fixes:

- Fix the handling of invalid JSON bodies in the `bottle` parser to support `bottle` versions `>=0.13` (#974).

Other changes:

- `MultiDictProxy` now inherits from `MutableMapping` rather than

    `Mapping` (#960).

## 8.5.0 (2024-04-25)

Other changes:

- Test against Python 3.12.

- Async location loading now supports loader functions which are not themselves async, but which return an awaitable result. This means that users who are already handling awaitable objects can return them from non-async loaders and expect `webargs` to `await` them. This allows some async interactions with supported frameworks, where the `webargs`-provided parser returns a framework object and the framework can be set to return awaitables, e.g., the Falcon parser. Thanks @j0k2r for the PR! (#935)

## 8.4.0 (2024-01-07)

Features:

- Add a new class attribute, `empty_value` to `DelimitedList` and `DelimitedTuple`, with a default of `""`. This controls the value deserialized when an empty string is seen.

`empty_value` can be used to handle types other than strings more gracefully, e.g.

    from webargs import fields

    class IntList(fields.DelimitedList):
        empty_value = 0

    myfield = IntList(fields.Int())

Note

`empty_value` will be changing in webargs v9.0 to be `missing` by default. This will allow use of fields with `load_default` to specify handling of the empty value.

- The rule for default argument names has been made configurable by overriding the `get_default_arg_name` method. This is described in the argument passing documentation.

Other changes:

- Drop support for Python 3.7, which is EOL.

- Type annotations for `FlaskParser` have been improved.

## 8.3.0 (2023-07-10)

Features:

- `webargs.Parser` now inherits from `typing.Generic` and is parametrizable over the type of the request object. Various framework-specific parsers are parametrized over their relevant request object classes.

- `webargs.Parser` and its subclasses now support passing arguments as a single keyword argument without expanding the parsed data into its components. For more details, see advanced docs on `Argument Passing and arg_name`.

Other changes:

- Type annotations have been improved to allow `Mapping` for dict-like schemas where previously `dict` was used. This makes the type covariant rather than invariant (#836).

- Test against Python 3.11 (#787).

## 8.2.0 (2022-07-11)

Features:

- A new method, `webargs.Parser.async_parse`, can be used for async-aware parsing from the base parser class. This can handle async location loader functions and async error handlers.

- `webargs.Parser.use_args` and `use_kwargs` can now be used to decorate async functions, and will use `async_parse` if the decorated function is also async. They will call the non-async `parse` method when used to decorate non-async functions.

- As a result of the changes to `webargs.Parser`, `FlaskParser`, `DjangoParser`, and `FalconParser` now all support async views. Thanks @Isira-Seneviratne for the initial PR.

Changes:

- The implementation of `AsyncParser` has changed. Now that `webargs.Parser` has built-in support for async usage, the primary purpose of `AsyncParser` is to redefine `parse` as an alias for `async_parse`

- Set `python_requires>=3.7.2` in package metadata (#692). Thanks @kasium for the PR.

## 8.1.0 (2022-01-12)

Bug fixes:

- Fix publishing type hints per PEP-561. (#650).

- Add DelimitedTuple to fields.__all__ (#678).

- Narrow type of `argmap` from `Mapping` to `Dict` (#682).

Other changes:

- Test against Python 3.10 (#647).

- Drop support for Python 3.6 (#673).

- Address distutils deprecation warning in Python 3.10 (#652). Thanks @kkirsche for the PR.

- Use postponed evaluation of annotations (#663). Thanks @Isira-Seneviratne for the PR.

- Pin mypy version in tox (#674).

- Improve type annotations for `__version_info__` (#680).

## 8.0.1 (2021-08-12)

Bug fixes:

- Fix “`DelimitedList` deserializes empty string as `['']`” (#623). Thanks @TTWSchell for reporting and for the PR.

Other changes:

- New documentation theme with `furo`. Thanks to @pradyunsg for writing furo!

- Webargs has a new logo. Thanks to @michaelizergit! (#312)

- Don’t build universal wheels. We don’t support Python 2 anymore. (#632)

- Make the build reproducible (#631).

## 8.0.0 (2021-04-08)

Features:

- Add `Parser.pre_load` as a method for allowing users to modify data before schema loading, but without redefining location loaders. See advanced docs on `Parser pre_load` for usage information. (#583)

- Backwards-incompatible: `unknown` defaults to `None` for body locations (`json`, `form` and `json_or_form`) (#580).

- Detection of fields as “multi-value” for unpacking lists from multi-dict types is now extensible with the `is_multiple` attribute. If a field sets `is_multiple = True` it will be detected as a multi-value field. If `is_multiple` is not set or is set to `None`, webargs will check if the field is an instance of `List` or `Tuple`. (#563)

- A new attribute on `Parser` objects, `Parser.KNOWN_MULTI_FIELDS` can be used to set fields which should be detected as `is_multiple=True` even when the attribute is not set (#592).

See docs on “Multi-Field Detection” for more details.

Bug fixes:

- `Tuple` field now behaves as a “multiple” field (#585).

## 7.0.1 (2020-12-14)

Bug fixes:

- Fix `DelimitedList` and `DelimitedTuple` to pass additional keyword arguments through their `_serialize` methods to the child fields and fix type checking on these classes. (#569) Thanks to @decaz for reporting.

## 7.0.0 (2020-12-10)

Changes:

- Backwards-incompatible: Drop support for webapp2 (#565).

- Add type annotations to `Parser` class, `DelimitedList`, and `DelimitedTuple`. (#566)

## 7.0.0b2 (2020-12-01)

Features:

- `DjangoParser` now supports the `headers` location. (#540)

- `FalconParser` now supports a new `media` location, which uses Falcon’s `media` decoding. (#253)

`media` behaves very similarly to the `json` location but also supports any registered media handler. See the Falcon documentation on media types for more details.

Changes:

- `FalconParser` defaults to the `media` location instead of `json`. (#253)

- Test against Python 3.9 (#552).

- Backwards-incompatible: Drop support for Python 3.5 (#553).

## 7.0.0b1 (2020-09-11)

Refactoring:

- Backwards-incompatible: Remove support for marshmallow2 (#539)

- Backwards-incompatible: Remove `dict2schema`

  Users desiring the `dict2schema` functionality may now rely upon `marshmallow.Schema.from_dict`. Rewrite any code using `dict2schema` like so:

    import marshmallow as ma

    # webargs 6.x and older
    from webargs import dict2schema

    myschema = dict2schema({"q1", ma.fields.Int()})

    # webargs 7.x
    myschema = ma.Schema.from_dict({"q1", ma.fields.Int()})

Features:

- Add `unknown` as a parameter to `Parser.parse`, `Parser.use_args`, `Parser.use_kwargs`, and parser instantiation. When set, it will be passed to `Schema.load`. When not set, the value passed will depend on the parser’s settings. If set to `None`, the schema’s default behavior will be used (i.e. no value is passed to `Schema.load`) and parser settings will be ignored.

This allows usages like

    import marshmallow as ma

    @parser.use_kwargs(
        {"q1": ma.fields.Int(), "q2": ma.fields.Int()}, location="query", unknown=ma.EXCLUDE
    )
    def foo(q1, q2): ...

- Defaults for `unknown` may be customized on parser classes via `Parser.DEFAULT_UNKNOWN_BY_LOCATION`, which maps location names to values to use.

Usages are varied, but include

    import marshmallow as ma
    from webargs.flaskparser import FlaskParser

    # as well as...
    class MyParser(FlaskParser):
        DEFAULT_UNKNOWN_BY_LOCATION = {"query": ma.INCLUDE}

    parser = MyParser()

Setting the `unknown` value for a Parser instance has higher precedence. So

    parser = MyParser(unknown=ma.RAISE)

will always pass `RAISE`, even when the location is `query`.

- By default, webargs will pass `unknown=EXCLUDE` for all locations except for request bodies (`json`, `form`, and `json_or_form`) and path parameters. Request bodies and path parameters will pass `unknown=RAISE`. This behavior is defined by the default value for `DEFAULT_UNKNOWN_BY_LOCATION`.

Changes:

- Registered `error_handler` callbacks are required to raise an exception. If a handler is invoked and no exception is raised, `webargs` will raise a `ValueError` (#527)

## 6.1.1 (2020-09-08)

Bug fixes:

- Failure to validate flask headers would produce error data which contained tuples as keys, and was therefore not JSON-serializable. (#500) These errors will now extract the headername as the key correctly. Thanks to @shughes-uk for reporting.

## 6.1.0 (2020-04-05)

Features:

- Add `fields.DelimitedTuple` when using marshmallow 3. This behaves as a combination of `fields.DelimitedList` and `marshmallow.fields.Tuple`. It takes an iterable of fields, plus a delimiter (defaults to `,`), and parses delimiter-separated strings into tuples. (#509)

- Add `__str__` and `__repr__` to MultiDictProxy to make it easier to work with (#488)

Support:

- Various docs updates (#482, #486, #489, #498, #508). Thanks @lefterisjp, @timgates42, and @ugultopu for the PRs.

## 6.0.0 (2020-02-27)

Features:

- `FalconParser`: Pass request content length to `req.stream.read` to provide compatibility with `falcon.testing` (#477). Thanks @suola for the PR.

- Backwards-incompatible: Factorize the `use_args` / `use_kwargs` branch in all parsers. When `as_kwargs` is `False`, arguments are now consistently appended to the arguments list by the `use_args` decorator. Before this change, the `PyramidParser` would prepend the argument list on each call to `use_args`. Pyramid view functions must reverse the order of their arguments. (#478)

## 6.0.0b8 (2020-02-16)

Refactoring:

- Backwards-incompatible: Use keyword-only arguments (#472).

## 6.0.0b7 (2020-02-14)

Features:

- Backwards-incompatible: webargs will rewrite the error messages in ValidationErrors to be namespaced under the location which raised the error. The `messages` field on errors will therefore be one layer deeper with a single top-level key.

## 6.0.0b6 (2020-01-31)

Refactoring:

- Remove the cache attached to webargs parsers. Due to changes between webargs v5 and v6, the cache is no longer considered useful.

Other changes:

- Import `Mapping` from `collections.abc` in pyramidparser.py (#471). Thanks @tirkarthi for the PR.

## 6.0.0b5 (2020-01-30)

Refactoring:

- Backwards-incompatible: `DelimitedList` now requires that its input be a string and always serializes as a string. It can still serialize and deserialize using another field, e.g. `DelimitedList(Int())` is still valid and requires that the values in the list parse as ints.

## 6.0.0b4 (2020-01-28)

Bug fixes:

- CVE CVE-2020-7965: Don’t attempt to parse JSON if request’s content type is mismatched (bugfix from 5.5.3).

## 6.0.0b3 (2020-01-21)

Features:

- Backwards-incompatible: Support Falcon 2.0. Drop support for Falcon 1.x (#459). Thanks @dodumosu and @Nateyo for the PR.

## 6.0.0b2 (2020-01-07)

Other changes:

- Backwards-incompatible: Drop support for Python 2 (#440). Thanks @hugovk for the PR.

## 6.0.0b1 (2020-01-06)

Features:

- Backwards-incompatible: Schemas will now load all data from a location, not only data specified by fields. As a result, schemas with validators which examine the full input data may change in behavior. The `unknown` parameter on schemas may be used to alter this. For example, `unknown=marshmallow.EXCLUDE` will produce a behavior similar to webargs v5.

Bug fixes:

- Backwards-incompatible: All parsers now require the Content-Type to be set correctly when processing JSON request bodies. This impacts `DjangoParser`, `FalconParser`, `FlaskParser`, and `PyramidParser`

Refactoring:

- Backwards-incompatible: Schema fields may not specify a location any longer, and `Parser.use_args` and `Parser.use_kwargs` now accept `location` (singular) instead of `locations` (plural). Instead of using a single field or schema with multiple `locations`, users are recommended to make multiple calls to `use_args` or `use_kwargs` with a distinct schema per location. For example, code should be rewritten like this:

    # webargs 5.x and older
    @parser.use_args(
        {
            "q1": ma.fields.Int(location="query"),
            "q2": ma.fields.Int(location="query"),
            "h1": ma.fields.Int(location="headers"),
        },
        locations=("query", "headers"),
    )
    def foo(q1, q2, h1): ...

    # webargs 6.x
    @parser.use_args({"q1": ma.fields.Int(), "q2": ma.fields.Int()}, location="query")
    @parser.use_args({"h1": ma.fields.Int()}, location="headers")
    def foo(q1, q2, h1): ...

- The `location_handler` decorator has been removed and replaced with `location_loader`. `location_loader` serves the same purpose (letting you write custom hooks for loading data) but its expected method signature is different. See the docs on `location_loader` for proper usage.

Thanks @sirosen for the PR!

## 5.5.3 (2020-01-28)

Bug fixes:

- CVE CVE-2020-7965: Don’t attempt to parse JSON if request’s content type is mismatched.

## 5.5.2 (2019-10-06)

Bug fixes:

- Handle `UnicodeDecodeError` when parsing JSON payloads (#427). Thanks @lindycoder for the catch and patch.

## 5.5.1 (2019-09-15)

Bug fixes:

- Remove usage of deprecated `Field.fail` when using marshmallow 3.

## 5.5.0 (2019-09-07)

Support:

- Various docs updates (#414, #421).

Refactoring:

- Don’t mutate `globals()` in `webargs.fields` (#411).

- Use marshmallow 3’s `Schema.from_dict` if available (#415).

## 5.4.0 (2019-07-23)

Changes:

- Use explicit type check for `fields.DelimitedList` when deciding to parse value with `getlist()` (#406 (comment) ).

Support:

- Add “Parsing Lists in Query Strings” section to docs (#406).

## 5.3.2 (2019-06-19)

Bug fixes:

- marshmallow 3.0.0rc7 compatibility (#395).

## 5.3.1 (2019-05-05)

Bug fixes:

- marshmallow 3.0.0rc6 compatibility (#384).

## 5.3.0 (2019-04-08)

Features:

- Add `"path"` location to `AIOHTTPParser`, `FlaskParser`, and `PyramidParser` (#379). Thanks @zhenhua32 for the PR.

- Add `webargs.__version_info__`.

## 5.2.0 (2019-03-16)

Features:

- Make the schema class used when generating a schema from a dict overridable (#375). Thanks @ThiefMaster.

## 5.1.3 (2019-03-11)

Bug fixes:

- CVE CVE-2019-9710: Fix race condition between parallel requests when the cache is used (#371). Thanks @ThiefMaster for reporting and fixing.

## 5.1.2 (2019-02-03)

Bug fixes:

- Remove lingering usages of `ValidationError.status_code` (#365). Thanks @decaz for reporting.

- Avoid `AttributeError` on Python<3.5.4 (#366).

- Fix incorrect type annotations for `error_headers`.

- Fix outdated docs (#367). Thanks @alexandersoto for reporting.

## 5.1.1.post0 (2019-01-30)

- Include LICENSE in sdist (#364).

## 5.1.1 (2019-01-28)

Bug fixes:

- Fix installing `simplejson` on Python 2 by distributing a Python 2-only wheel (#363).

## 5.1.0 (2019-01-11)

Features:

- Error handlers for `AsyncParser` classes may be coroutine functions.

- Add type annotations to `AsyncParser` and `AIOHTTPParser`.

Bug fixes:

- Fix compatibility with Flask<1.0 (#355). Thanks @hoatle for reporting.

- Address warning on Python 3.7 about importing from `collections.abc`.

## 5.0.0 (2019-01-03)

Features:

- Backwards-incompatible: A 400 HTTPError is raised when an invalid JSON payload is passed. (#329). Thanks @zedrdave for reporting.

Other changes:

- Backwards-incompatible: `webargs.argmap2schema` is removed. Use `webargs.dict2schema` instead.

- Backwards-incompatible: `webargs.ValidationError` is removed. Use `marshmallow.ValidationError` instead.

    # <5.0.0
    from webargs import ValidationError

    def auth_validator(value):
        # ...
        raise ValidationError("Authentication failed", status_code=401)

    @use_args({"auth": fields.Field(validate=auth_validator)})
    def auth_view(args):
        return jsonify(args)

    # >=5.0.0
    from marshmallow import ValidationError

    def auth_validator(value):
        # ...
        raise ValidationError("Authentication failed")

    @use_args({"auth": fields.Field(validate=auth_validator)}, error_status_code=401)
    def auth_view(args):
        return jsonify(args)

- Backwards-incompatible: Missing arguments will no longer be filled in when using `@use_kwargs` (#342, #307, #252). Use `**kwargs` to account for non-required fields.

    # <5.0.0
    @use_kwargs(
        {"first_name": fields.Str(required=True), "last_name": fields.Str(required=False)}
    )
    def myview(first_name, last_name):
        # last_name is webargs.missing if it's missing from the request
        return {"first_name": first_name}

    # >=5.0.0
    @use_kwargs(
        {"first_name": fields.Str(required=True), "last_name": fields.Str(required=False)}
    )
    def myview(first_name, **kwargs):
        # last_name will not be in kwargs if it's missing from the request
        return {"first_name": first_name}

- simplejson is now a required dependency on Python 2 (#334). This ensures consistency of behavior across Python 2 and 3.

## 4.4.1 (2018-01-03)

Bug fixes:

- Remove usages of `argmap2schema` from `fields.Nested`, `AsyncParser`, and `PyramidParser`.

## 4.4.0 (2019-01-03)

- Deprecation: `argmap2schema` is deprecated in favor of `dict2schema` (#352).

## 4.3.1 (2018-12-31)

- Add `force_all` param to `PyramidParser.use_args`.

- Add warning about missing arguments to `AsyncParser`.

## 4.3.0 (2018-12-30)

- Deprecation: Add warning about missing arguments getting added to parsed arguments dictionary (#342). This behavior will be removed in version 5.0.0.

## 4.2.0 (2018-12-27)

Features:

- Add `force_all` argument to `use_args` and `use_kwargs` (#252, #307). Thanks @piroux for reporting.

- Deprecation: The `status_code` and `headers` arguments to `ValidationError` are deprecated. Pass `error_status_code` and `error_headers` to `Parser.parse`, `Parser.use_args`, and `Parser.use_kwargs` instead. (#327, #336).

- Custom error handlers receive `error_status_code` and `error_headers` arguments. (#327).

    # <4.2.0
    @parser.error_handler
    def handle_error(error, req, schema):
        raise CustomError(error.messages)

    class MyParser(FlaskParser):
        def handle_error(self, error, req, schema):
            # ...
            raise CustomError(error.messages)

    # >=4.2.0
    @parser.error_handler
    def handle_error(error, req, schema, status_code, headers):
        raise CustomError(error.messages)

    # OR

    @parser.error_handler
    def handle_error(error, **kwargs):
        raise CustomError(error.messages)

    class MyParser(FlaskParser):
        def handle_error(self, error, req, schema, status_code, headers):
            # ...
            raise CustomError(error.messages)

        # OR

        def handle_error(self, error, req, **kwargs):
            # ...
            raise CustomError(error.messages)

Legacy error handlers will be supported until version 5.0.0.

## 4.1.3 (2018-12-02)

Bug fixes:

- Fix bug in `AIOHTTParser` that prevented calling `use_args` on the same view function multiple times (#273). Thanks to @dnp1 for reporting and @jangelo for the fix.

- Fix compatibility with marshmallow 3.0.0rc1 (#330).

## 4.1.2 (2018-11-03)

Bug fixes:

- Fix serialization behavior of `DelimitedList` (#319). Thanks @lee3164 for the PR.

Other changes:

- Test against Python 3.7.

## 4.1.1 (2018-10-25)

Bug fixes:

- Fix bug in `AIOHTTPParser` that caused a `JSONDecode` error when parsing empty payloads (#229). Thanks @explosic4 for reporting and thanks user @kochab for the PR.

## 4.1.0 (2018-09-17)

Features:

- Add `webargs.testing` module, which exposes `CommonTestCase` to third-party parser libraries (see comments in #287).

## 4.0.0 (2018-07-15)

Features:

- Backwards-incompatible: Custom error handlers receive the `marshmallow.Schema` instance as the third argument. Update any functions decorated with `Parser.error_handler` to take a `schema` argument, like so:

    # 3.x
    @parser.error_handler
    def handle_error(error, req):
        raise CustomError(error.messages)

    # 4.x
    @parser.error_handler
    def handle_error(error, req, schema):
        raise CustomError(error.messages)

See marshmallow-code/marshmallow#840 (comment) for more information about this change.

Bug fixes:

- Backwards-incompatible: Rename `webargs.async` to `webargs.asyncparser` to fix compatibility with Python 3.7 (#240). Thanks @Reskov for the catch and patch.

Other changes:

- Backwards-incompatible: Drop support for Python 3.4 (#243). Python 2.7 and >=3.5 are supported.

- Backwards-incompatible: Drop support for marshmallow<2.15.0. marshmallow>=2.15.0 and >=3.0.0b12 are officially supported.

- Use black with pre-commit for code formatting (#244).

## 3.0.2 (2018-07-05)

Bug fixes:

- Fix compatibility with marshmallow 3.0.0b12 (#242). Thanks @lafrech.

## 3.0.1 (2018-06-06)

Bug fixes:

- Respect `Parser.DEFAULT_VALIDATION_STATUS` when a `status_code` is not explicitly passed to `ValidationError` (#180). Thanks @foresmac for finding this.

Support:

- Add “Returning HTTP 400 Responses” section to docs (#180).

## 3.0.0 (2018-05-06)

Changes:

- Backwards-incompatible: Custom error handlers receive the request object as the second argument. Update any functions decorated with `Parser.error_handler` to take a `req` argument, like so:

    # 2.x
    @parser.error_handler
    def handle_error(error):
        raise CustomError(error.messages)

    # 3.x
    @parser.error_handler
    def handle_error(error, req):
        raise CustomError(error.messages)

- Backwards-incompatible: Remove unused `instance` and `kwargs` arguments of `argmap2schema`.

- Backwards-incompatible: Remove `Parser.load` method (`Parser` now calls `Schema.load` directly).

These changes shouldn’t affect most users. However, they might break custom parsers calling these methods. (#222)

- Drop support for aiohttp<3.0.0.

## 2.1.0 (2018-04-01)

Features:

- Respect `data_key` field argument (in marshmallow 3). Thanks @lafrech.

## 2.0.0 (2018-02-08)

Changes:

- Drop support for aiohttp<2.0.0.

- Remove use of deprecated `Request.has_body` attribute in aiohttpparser (#186). Thanks @ariddell for reporting.

## 1.10.0 (2018-02-08)

Features:

- Add support for marshmallow>=3.0.0b7 (#188). Thanks @lafrech.

Deprecations:

- Support for aiohttp<2.0.0 is deprecated and will be removed in webargs 2.0.0.

## 1.9.0 (2018-02-03)

Changes:

- `HTTPExceptions` raised with `webargs.flaskparser.abort` will always have the `data` attribute, even if no additional keywords arguments are passed (#184). Thanks @lafrech.

Support:

- Fix examples in examples/ directory.

## 1.8.1 (2017-07-17)

Bug fixes:

- Fix behavior of `AIOHTTPParser.use_args` when `as_kwargs=True` is passed with a `Schema` (#179). Thanks @Itayazolay.

## 1.8.0 (2017-07-16)

Features:

- `AIOHTTPParser` supports class-based views, i.e. `aiohttp.web.View` (#177). Thanks @daniel98321.

## 1.7.0 (2017-06-03)

Features:

- `AIOHTTPParser.use_args` and `AIOHTTPParser.use_kwargs` work with `async def` coroutines (#170). Thanks @zaro.

## 1.6.3 (2017-05-18)

Support:

- Fix Flask error handling docs in “Framework support” section (#168). Thanks @nebularazer.

## 1.6.2 (2017-05-16)

Bug fixes:

- Fix parsing multiple arguments in `AIOHTTParser` (#165). Thanks @ariddell for reporting and thanks @zaro for reporting.

## 1.6.1 (2017-04-30)

Bug fixes:

- Fix form parsing in aiohttp>=2.0.0. Thanks @DmitriyS for the PR.

## 1.6.0 (2017-03-14)

Bug fixes:

- Fix compatibility with marshmallow 3.x.

Other changes:

- Drop support for Python 2.6 and 3.3.

- Support marshmallow>=2.7.0.

## 1.5.3 (2017-02-04)

Bug fixes:

- Port fix from release 1.5.2 to `AsyncParser`. This fixes #146 for `AIOHTTPParser`.

- Handle invalid types passed to `DelimitedList` (#149). Thanks @psconnect-dev for reporting.

## 1.5.2 (2017-01-08)

Bug fixes:

- Don’t add `marshmallow.missing` to `original_data` when using `marshmallow.validates_schema(pass_original=True)` (#146). Thanks @lafrech for reporting and for the fix.

Other changes:

- Test against Python 3.6.

## 1.5.1 (2016-11-27)

Bug fixes:

- Fix handling missing nested args when `many=True` (#120, #145). Thanks @chavz and @Bangertm for reporting.

- Fix behavior of `load_from` in `AIOHTTPParser`.

## 1.5.0 (2016-11-22)

Features:

- The `use_args` and `use_kwargs` decorators add a reference to the undecorated function via the `__wrapped__` attribute. This is useful for unit-testing purposes (#144). Thanks @EFF for the PR.

Bug fixes:

- If `load_from` is specified on a field, first check the field name before checking `load_from` (#118). Thanks @jasonab for reporting.

## 1.4.0 (2016-09-29)

Bug fixes:

- Prevent error when rendering validation errors to JSON in Flask (e.g. when using Flask-RESTful) (#122). Thanks @frol for the catch and patch. NOTE: Though this is a bugfix, this is a potentially breaking change for code that needs to access the original `ValidationError` object.

    # Before
    @app.errorhandler(422)
    def handle_validation_error(err):
        return jsonify({"errors": err.messages}), 422

    # After
    @app.errorhandler(422)
    def handle_validation_error(err):
        # The marshmallow.ValidationError is available on err.exc
        return jsonify({"errors": err.exc.messages}), 422

## 1.3.4 (2016-06-11)

Bug fixes:

- Fix bug in parsing form in Falcon>=1.0.

## 1.3.3 (2016-05-29)

Bug fixes:

- Fix behavior for nullable List fields (#107). Thanks @shaicantor for reporting.

## 1.3.2 (2016-04-14)

Bug fixes:

- Fix passing a schema factory to `use_kwargs` (#103). Thanks @ksesong for reporting.

## 1.3.1 (2016-04-13)

Bug fixes:

- Fix memory leak when calling `parser.parse` with a `dict` in a view (#101). Thanks @frankslaughter for reporting.

- aiohttpparser: Fix bug in handling bulk-type arguments.

Support:

- Massive refactor of tests (#98).

- Docs: Fix incorrect use_args example in Tornado section (#100). Thanks @frankslaughter for reporting.

- Docs: Add “Mixing Locations” section (#90). Thanks @tuukkamustonen.

## 1.3.0 (2016-04-05)

Features:

- Add bulk-type arguments support for JSON parsing by passing `many=True` to a `Schema` (#81). Thanks @frol.

Bug fixes:

- Fix JSON parsing in Flask<=0.9.0. Thanks @brettdh for the PR.

- Fix behavior of `status_code` argument to `ValidationError` (#85). This requires marshmallow>=2.7.0. Thanks @ParthGandhi for reporting.

Support:

- Docs: Add “Custom Fields” section with example of using a `Function` field (#94). Thanks @brettdh for the suggestion.

## 1.2.0 (2016-01-04)

Features:

- Add `view_args` request location to `FlaskParser` (#82). Thanks @oreza for the suggestion.

Bug fixes:

- Use the value of `load_from` as the key for error messages when it is provided (#83). Thanks @immerrr for the catch and patch.

## 1.1.1 (2015-11-14)

Bug fixes:

- aiohttpparser: Fix bug that raised a `JSONDecodeError` raised when parsing non-JSON requests using default `locations` (#80). Thanks @leonidumanskiy for reporting.

- Fix parsing JSON requests that have a vendor media type, e.g. `application/vnd.api+json`.

## 1.1.0 (2015-11-08)

Features:

- `Parser.parse`, `Parser.use_args` and `Parser.use_kwargs` can take a Schema factory as the first argument (#73). Thanks @DamianHeard for the suggestion and the PR.

Support:

- Docs: Add “Custom Parsers” section with example of parsing nested querystring arguments (#74). Thanks @dwieeb.

- Docs: Add “Advanced Usage” page.

## 1.0.0 (2015-10-19)

Features:

- Add `AIOHTTPParser` (#71).

- Add `webargs.async` module with `AsyncParser`.

Bug fixes:

- If an empty list is passed to a List argument, it will be parsed as an empty list rather than being excluded from the parsed arguments dict (#70). Thanks @mTatcher for catching this.

Other changes:

- Backwards-incompatible: When decorating resource methods with `FalconParser.use_args`, the parsed arguments dictionary will be positioned after the request and response arguments.

- Backwards-incompatible: When decorating views with `DjangoParser.use_args`, the parsed arguments dictionary will be positioned after the request argument.

- Backwards-incompatible: `Parser.get_request_from_view_args` gets passed a view function as its first argument.

- Backwards-incompatible: Remove logging from default error handlers.

## 0.18.0 (2015-10-04)

Features:

- Add `FalconParser` (#63).

- Add `fields.DelimitedList` (#66). Thanks @jmcarp.

- `TornadoParser` will parse json with `simplejson` if it is installed.

- `BottleParser` caches parsed json per-request for improved performance.

No breaking changes. Yay!

## 0.17.0 (2015-09-29)

Features:

- `TornadoParser` returns unicode strings rather than bytestrings (#41). Thanks @thomasboyt for the suggestion.

- Add `Parser.get_default_request` and `Parser.get_request_from_view_args` hooks to simplify `Parser` implementations.

- Backwards-compatible: `webargs.core.get_value` takes a `Field` as its last argument. Note: this is technically a breaking change, but this won’t affect most users since `get_value` is only used internally by `Parser` classes.

Support:

- Add `examples/annotations_example.py` (demonstrates using Python 3 function annotations to define request arguments).

- Fix examples. Thanks @hyunchel for catching an error in the Flask error handling docs.

Bug fixes:

- Correctly pass `validate` and `force_all` params to `PyramidParser.use_args`.

## 0.16.0 (2015-09-27)

The major change in this release is that webargs now depends on marshmallow for defining arguments and validation.

Your code will need to be updated to use `Fields` rather than `Args`.

    # Old API
    from webargs import Arg

    args = {
        "name": Arg(str, required=True),
        "password": Arg(str, validate=lambda p: len(p) >= 6),
        "display_per_page": Arg(int, default=10),
        "nickname": Arg(multiple=True),
        "Content-Type": Arg(dest="content_type", location="headers"),
        "location": Arg({"city": Arg(str), "state": Arg(str)}),
        "meta": Arg(dict),
    }

    # New API
    from webargs import fields

    args = {
        "name": fields.Str(required=True),
        "password": fields.Str(validate=lambda p: len(p) >= 6),
        "display_per_page": fields.Int(load_default=10),
        "nickname": fields.List(fields.Str()),
        "content_type": fields.Str(load_from="Content-Type"),
        "location": fields.Nested({"city": fields.Str(), "state": fields.Str()}),
        "meta": fields.Dict(),
    }

Features:

- Error messages for all arguments are “bundled” (#58).

Changes:

- Backwards-incompatible: Replace `Args` with marshmallow fields (#61).

- Backwards-incompatible: When using `use_kwargs`, missing arguments will have the special value `missing` rather than `None`.

- `TornadoParser` raises a custom `HTTPError` with a `messages` attribute when validation fails.

Bug fixes:

- Fix required validation of nested arguments (#39, #51). These are fixed by virtue of using marshmallow’s `Nested` field. Thanks @ewang and @chavz for reporting.

Support:

- Updated docs.

- Add `examples/schema_example.py`.

- Tested against Python 3.5.

## 0.15.0 (2015-08-22)

Changes:

- If a parsed argument is `None`, the type conversion function is not called #54. Thanks @marcellarius.

Bug fixes:

- Fix parsing nested `Args` when the argument is missing from the input (#52). Thanks @stas.

## 0.14.0 (2015-06-28)

Features:

- Add parsing of `matchdict` to `PyramidParser`. Thanks @hartror.

Bug fixes:

- Fix `PyramidParser's` `use_kwargs` method (#42). Thanks @hartror for the catch and patch.

- Correctly use locations passed to Parser’s constructor when using `use_args` (#44). Thanks @jacebrowning for the catch and patch.

- Fix behavior of `default` and `dest` argument on nested `Args` (#40 and #46). Thanks @stas.

Changes:

- A 422 response is returned to the client when a `ValidationError` is raised by a parser (#38).

## 0.13.0 (2015-04-05)

Features:

- Support for webapp2 via the `webargs.webapp2parser` module. Thanks @Trii.

- Store argument name on `RequiredArgMissingError`. Thanks @stas.

- Allow error messages for required validation to be overriden. Thanks again @stas.

Removals:

- Remove `source` parameter from `Arg`.

## 0.12.0 (2015-03-22)

Features:

- Store argument name on `ValidationError` (#32). Thanks @alexmic for the suggestion. Thanks @stas for the patch.

- Allow nesting of dict subtypes.

## 0.11.0 (2015-03-01)

Changes:

- Add `dest` parameter to `Arg` constructor which determines the key to be added to the parsed arguments dictionary (#32).

- Backwards-incompatible: Rename `targets` parameter to `locations` in `Parser` constructor, `Parser#parse_arg`, `Parser#parse`, `Parser#use_args`, and `Parser#use_kwargs`.

- Backwards-incompatible: Rename `Parser#target_handler` to `Parser#location_handler`.

Deprecation:

- The `source` parameter is deprecated in favor of the `dest` parameter.

Bug fixes:

- Fix `validate` parameter of `DjangoParser#use_args`.

## 0.10.0 (2014-12-23)

- When parsing a nested `Arg`, filter out extra arguments that are not part of the `Arg's` nested `dict` (#28). Thanks Derrick Gilland for the suggestion.

- Fix bug in parsing `Args` with both type coercion and `multiple=True` (#30). Thanks Steven Manuatu for reporting.

- Raise `RequiredArgMissingError` when a required argument is missing on a request.

## 0.9.1 (2014-12-11)

- Fix behavior of `multiple=True` when nesting Args (#29). Thanks Derrick Gilland for reporting.

## 0.9.0 (2014-12-08)

- Pyramid support thanks to @philtay.

- User-friendly error messages when `Arg` type conversion/validation fails. Thanks Andriy Yurchuk.

- Allow `use` argument to be a list of functions.

- Allow `Args` to be nested within each other, e.g. for nested dict validation. Thanks @saritasa for the suggestion.

- Backwards-incompatible: Parser will only pass `ValidationErrors` to its error handler function, rather than catching all generic Exceptions.

- Backwards-incompatible: Rename `Parser.TARGET_MAP` to `Parser.__target_map__`.

- Add a short-lived cache to the `Parser` class that can be used to store processed request data for reuse.

- Docs: Add example usage with Flask-RESTful.

## 0.8.1 (2014-10-28)

- Fix bug in `TornadoParser` that raised an error when request body is not a string (e.g when it is a `Future`). Thanks Josh Carp.

## 0.8.0 (2014-10-26)

- Fix `Parser.use_kwargs` behavior when an `Arg` is allowed missing. The `allow_missing` attribute is ignored when `use_kwargs` is called.

- `default` may be a callable.

- Allow `ValidationError` to specify a HTTP status code for the error response.

- Improved error logging.

- Add `'query'` as a valid target name.

- Allow a list of validators to be passed to an `Arg` or `Parser.parse`.

- A more useful `__repr__` for `Arg`.

- Add examples and updated docs.

## 0.7.0 (2014-10-18)

- Add `source` parameter to `Arg` constructor. Allows renaming of keys in the parsed arguments dictionary. Thanks Josh Carp.

- `FlaskParser's` `handle_error` method attaches the string representation of validation errors on `err.data['message']`. The raised exception is stored on `err.data['exc']`.

- Additional keyword arguments passed to `Arg` are stored as metadata.

## 0.6.2 (2014-10-05)

- Fix bug in `TornadoParser's` `handle_error` method. Thanks Josh Carp.

- Add `error` parameter to `Parser` constructor that allows a custom error message to be used if schema-level validation fails.

- Fix bug that raised a `UnicodeEncodeError` on Python 2 when an Arg’s validator function received non-ASCII input.

## 0.6.1 (2014-09-28)

- Fix regression with parsing an `Arg` with both `default` and `target` set (see issue #11).

## 0.6.0 (2014-09-23)

- Add `validate` parameter to `Parser.parse` and `Parser.use_args`. Allows validation of the full parsed output.

- If `allow_missing` is `True` on an `Arg` for which `None` is explicitly passed, the value will still be present in the parsed arguments dictionary.

- Backwards-incompatible: `Parser's` `parse_*` methods return `webargs.core.Missing` if the value cannot be found on the request. NOTE: `webargs.core.Missing` will not show up in the final output of `Parser.parse`.

- Fix bug with parsing empty request bodies with `TornadoParser`.

## 0.5.1 (2014-08-30)

- Fix behavior of `Arg's` `allow_missing` parameter when `multiple=True`.

- Fix bug in tornadoparser that caused parsing JSON arguments to fail.

## 0.5.0 (2014-07-27)

- Fix JSON parsing in Flask parser when Content-Type header contains more than just `application/json`. Thanks Samir Uppaluru for reporting.

- Backwards-incompatible: The `use` parameter to `Arg` is called before type conversion occurs. Thanks Eric Wang for the suggestion.

- Tested on Tornado>=4.0.

## 0.4.0 (2014-05-04)

- Custom target handlers can be defined using the `Parser.target_handler` decorator.

- Error handler can be specified using the `Parser.error_handler` decorator.

- `Args` can define their request target by passing in a `target` argument.

- Backwards-incompatible: `DEFAULT_TARGETS` is now a class member of `Parser`. This allows subclasses to override it.

## 0.3.4 (2014-04-27)

- Fix bug that caused `use_args` to fail on class-based views in Flask.

- Add `allow_missing` parameter to `Arg`.

## 0.3.3 (2014-03-20)

- Awesome contributions from the open-source community!

- Add `use_kwargs` decorator. Thanks @venuatu.

- Tornado support thanks to @jvrsantacruz.

- Tested on Python 3.4.

## 0.3.2 (2014-03-04)

- Fix bug with parsing JSON in Flask and Bottle.

## 0.3.1 (2014-03-03)

- Remove print statements in core.py. Oops.

## 0.3.0 (2014-03-02)

- Add support for repeated parameters (#1).

- Backwards-incompatible: All `parse_*` methods take `arg` as their fourth argument.

- Add `error_handler` param to `Parser`.

## 0.2.0 (2014-02-26)

- Bottle support.

- Add `targets` param to `Parser`. Allows setting default targets.

- Add `files` target.

## 0.1.0 (2014-02-16)

- First release.

- Parses JSON, querystring, forms, headers, and cookies.

- Support for Flask and Django.