# -*- coding: utf-8 -*- """ flask.wrappers ~~~~~~~~~~~~~~ Implements the WSGI wrappers (request and response). :copyright: (c) 2015 by Armin Ronacher. :license: BSD, see LICENSE for more details. """ from werkzeug.wrappers import Request as RequestBase, Response as ResponseBase from werkzeug.exceptions import BadRequest from . import json from .globals import _app_ctx_stack _missing = object() class JSONMixin(object): """Mixin for both request and response classes to provide JSON parsing capabilities. .. versionadded:: 0.12 """ @property def is_json(self): """Indicates if this request/response is JSON or not. By default it is considered to include JSON data if the mimetype is :mimetype:`application/json` or :mimetype:`application/*+json`. """ mt = self.mimetype if mt == 'application/json': return True if mt.startswith('application/') and mt.endswith('+json'): return True return False @property def json(self): """If the mimetype is :mimetype:`application/json` this will contain the parsed JSON data. Otherwise this will be ``None``. The :meth:`get_json` method should be used instead. """ from warnings import warn warn(DeprecationWarning('json is deprecated. ' 'Use get_json() instead.'), stacklevel=2) return self.get_json() def _get_data_for_json(self, cache): getter = getattr(self, 'get_data', None) if getter is not None: return getter(cache=cache) return self.data def get_json(self, force=False, silent=False, cache=True): """Parses the JSON request/response data and returns it. By default this function will return ``None`` if the mimetype is not :mimetype:`application/json` but this can be overridden by the ``force`` parameter. If parsing fails the :meth:`on_json_loading_failed` method on the request object will be invoked. :param force: if set to ``True`` the mimetype is ignored. :param silent: if set to ``True`` this method will fail silently and return ``None``. :param cache: if set to ``True`` the parsed JSON data is remembered on the request. """ rv = getattr(self, '_cached_json', _missing) if rv is not _missing: return rv if not (force or self.is_json): return None # We accept a request charset against the specification as certain # clients have been using this in the past. For responses, we assume # that if the response charset was set explicitly then the data had # been encoded correctly as well. charset = self.mimetype_params.get('charset') try: data = self._get_data_for_json(cache) if charset is not None: rv = json.loads(data, encoding=charset) else: rv = json.loads(data) except ValueError as e: if silent: rv = None else: rv = self.on_json_loading_failed(e) if cache: self._cached_json = rv return rv def on_json_loading_failed(self, e): """Called if decoding of the JSON data failed. The return value of this method is used by :meth:`get_json` when an error occurred. The default implementation just raises a :class:`BadRequest` exception. .. versionchanged:: 0.10 Removed buggy previous behavior of generating a random JSON response. If you want that behavior back you can trivially add it by subclassing. .. versionadded:: 0.8 """ ctx = _app_ctx_stack.top if ctx is not None and ctx.app.debug: raise BadRequest('Failed to decode JSON object: {0}'.format(e)) raise BadRequest() class Request(RequestBase, JSONMixin): """The request object used by default in Flask. Remembers the matched endpoint and view arguments. It is what ends up as :class:`~flask.request`. If you want to replace the request object used you can subclass this and set :attr:`~flask.Flask.request_class` to your subclass. The request object is a :class:`~werkzeug.wrappers.Request` subclass and provides all of the attributes Werkzeug defines plus a few Flask specific ones. """ #: The internal URL rule that matched the request. This can be #: useful to inspect which methods are allowed for the URL from #: a before/after handler (``request.url_rule.methods``) etc. #: #: .. versionadded:: 0.6 url_rule = None #: A dict of view arguments that matched the request. If an exception #: happened when matching, this will be ``None``. view_args = None #: If matching the URL failed, this is the exception that will be #: raised / was raised as part of the request handling. This is #: usually a :exc:`~werkzeug.exceptions.NotFound` exception or #: something similar. routing_exception = None # Switched by the request context until 1.0 to opt in deprecated # module functionality. _is_old_module = False @property def max_content_length(self): """Read-only view of the ``MAX_CONTENT_LENGTH`` config key.""" ctx = _app_ctx_stack.top if ctx is not None: return ctx.app.config['MAX_CONTENT_LENGTH'] @property def endpoint(self): """The endpoint that matched the request. This in combination with :attr:`view_args` can be used to reconstruct the same or a modified URL. If an exception happened when matching, this will be ``None``. """ if self.url_rule is not None: return self.url_rule.endpoint @property def module(self): """The name of the current module if the request was dispatched to an actual module. This is deprecated functionality, use blueprints instead. """ from warnings import warn warn(DeprecationWarning('modules were deprecated in favor of ' 'blueprints. Use request.blueprint ' 'instead.'), stacklevel=2) if self._is_old_module: return self.blueprint @property def blueprint(self): """The name of the current blueprint""" if self.url_rule and '.' in self.url_rule.endpoint: return self.url_rule.endpoint.rsplit('.', 1)[0] def _load_form_data(self): RequestBase._load_form_data(self) # In debug mode we're replacing the files multidict with an ad-hoc # subclass that raises a different error for key errors. ctx = _app_ctx_stack.top if ctx is not None and ctx.app.debug and \ self.mimetype != 'multipart/form-data' and not self.files: from .debughelpers import attach_enctype_error_multidict attach_enctype_error_multidict(self) class Response(ResponseBase, JSONMixin): """The response object that is used by default in Flask. Works like the response object from Werkzeug but is set to have an HTML mimetype by default. Quite often you don't have to create this object yourself because :meth:`~flask.Flask.make_response` will take care of that for you. If you want to replace the response object used you can subclass this and set :attr:`~flask.Flask.response_class` to your subclass. """ default_mimetype = 'text/html' def _get_data_for_json(self, cache): getter = getattr(self, 'get_data', None) if getter is not None: # Ignore the cache flag since response doesn't support it return getter() return self.data