Source code for webargs.aiohttpparser

"""aiohttp request argument parsing module.

Example: ::

    import asyncio
    from aiohttp import web

    from webargs import fields
    from webargs.aiohttpparser import use_args


    hello_args = {
        'name': fields.Str(required=True)
    }
    @asyncio.coroutine
    @use_args(hello_args)
    def index(request, args):
        return web.Response(
            body='Hello {}'.format(args['name']).encode('utf-8')
        )

    app = web.Application()
    app.router.add_route('GET', '/', index)
"""
import typing

from aiohttp import web
from aiohttp.web import Request
from aiohttp import web_exceptions
from marshmallow import Schema, ValidationError
from marshmallow.fields import Field

from webargs import core
from webargs.core import json
from webargs.asyncparser import AsyncParser


def is_json_request(req: Request) -> bool:
    content_type = req.content_type
    return core.is_json(content_type)


[docs]class HTTPUnprocessableEntity(web.HTTPClientError): status_code = 422
# Mapping of status codes to exception classes # Adapted from werkzeug exception_map = {422: HTTPUnprocessableEntity} def _find_exceptions() -> None: for name in web_exceptions.__all__: obj = getattr(web_exceptions, name) try: is_http_exception = issubclass(obj, web_exceptions.HTTPException) except TypeError: is_http_exception = False if not is_http_exception or obj.status_code is None: continue old_obj = exception_map.get(obj.status_code, None) if old_obj is not None and issubclass(obj, old_obj): continue exception_map[obj.status_code] = obj # Collect all exceptions from aiohttp.web_exceptions _find_exceptions() del _find_exceptions
[docs]class AIOHTTPParser(AsyncParser): """aiohttp request argument parser.""" __location_map__ = dict( match_info="parse_match_info", path="parse_match_info", **core.Parser.__location_map__ )
[docs] def parse_querystring(self, req: Request, name: str, field: Field) -> typing.Any: """Pull a querystring value from the request.""" return core.get_value(req.query, name, field)
[docs] async def parse_form(self, req: Request, name: str, field: Field) -> typing.Any: """Pull a form value from the request.""" post_data = self._cache.get("post") if post_data is None: self._cache["post"] = await req.post() return core.get_value(self._cache["post"], name, field)
[docs] async def parse_json(self, req: Request, name: str, field: Field) -> typing.Any: """Pull a json value from the request.""" json_data = self._cache.get("json") if json_data is None: if not (req.body_exists and is_json_request(req)): return core.missing try: json_data = await req.json(loads=json.loads) except json.JSONDecodeError as e: if e.doc == "": return core.missing else: return self.handle_invalid_json_error(e, req) self._cache["json"] = json_data return core.get_value(json_data, name, field, allow_many_nested=True)
[docs] def parse_headers(self, req: Request, name: str, field: Field) -> typing.Any: """Pull a value from the header data.""" return core.get_value(req.headers, name, field)
[docs] def parse_cookies(self, req: Request, name: str, field: Field) -> typing.Any: """Pull a value from the cookiejar.""" return core.get_value(req.cookies, name, field)
[docs] def parse_files(self, req: Request, name: str, field: Field) -> None: raise NotImplementedError( "parse_files is not implemented. You may be able to use parse_form for " "parsing upload data." )
[docs] def parse_match_info(self, req: Request, name: str, field: Field) -> typing.Any: """Pull a value from the request's ``match_info``.""" return core.get_value(req.match_info, name, field)
[docs] def get_request_from_view_args( self, view: typing.Callable, args: typing.Iterable, kwargs: typing.Mapping ) -> Request: """Get request object from a handler function or method. Used internally by ``use_args`` and ``use_kwargs``. """ req = None for arg in args: if isinstance(arg, web.Request): req = arg break elif isinstance(arg, web.View): req = arg.request break assert isinstance(req, web.Request), "Request argument not found for handler" return req
[docs] def handle_error( self, error: ValidationError, req: Request, schema: Schema, error_status_code: typing.Union[int, None] = None, error_headers: typing.Union[typing.Mapping[str, str], None] = None, ) -> "typing.NoReturn": """Handle ValidationErrors and return a JSON response of error messages to the client. """ error_class = exception_map.get( error_status_code or self.DEFAULT_VALIDATION_STATUS ) if not error_class: raise LookupError("No exception for {0}".format(error_status_code)) headers = error_headers raise error_class( body=json.dumps(error.messages).encode("utf-8"), headers=headers, content_type="application/json", )
def handle_invalid_json_error( self, error: json.JSONDecodeError, req: Request, *args, **kwargs ) -> "typing.NoReturn": error_class = exception_map[400] messages = {"json": ["Invalid JSON body."]} raise error_class( body=json.dumps(messages).encode("utf-8"), content_type="application/json" )
parser = AIOHTTPParser() use_args = parser.use_args # type: typing.Callable use_kwargs = parser.use_kwargs # type: typing.Callable