mirror of
https://github.com/encode/django-rest-framework.git
synced 2024-12-01 05:54:01 +03:00
639 lines
21 KiB
Python
639 lines
21 KiB
Python
"""
|
|
The :mod:`mixins` module provides a set of reusable `mixin`
|
|
classes that can be added to a `View`.
|
|
"""
|
|
|
|
from django.contrib.auth.models import AnonymousUser
|
|
from django.core.paginator import Paginator
|
|
from django.http import HttpResponse
|
|
|
|
from djangorestframework import status
|
|
from djangorestframework.renderers import BaseRenderer
|
|
from djangorestframework.resources import Resource, FormResource, ModelResource
|
|
from djangorestframework.response import Response, ErrorResponse
|
|
from djangorestframework.utils import MSIE_USER_AGENT_REGEX
|
|
from djangorestframework.utils.mediatypes import is_form_media_type, order_by_precedence
|
|
|
|
from StringIO import StringIO
|
|
|
|
|
|
__all__ = (
|
|
# Base behavior mixins
|
|
'RequestMixin',
|
|
'ResponseMixin',
|
|
'AuthMixin',
|
|
'ResourceMixin',
|
|
# Reverse URL lookup behavior
|
|
'InstanceMixin',
|
|
# Model behavior mixins
|
|
'ModelMixin',
|
|
)
|
|
|
|
|
|
########## Request Mixin ##########
|
|
|
|
class RequestMixin(object):
|
|
"""
|
|
`Mixin` class to provide request parsing behavior.
|
|
"""
|
|
|
|
_USE_FORM_OVERLOADING = True
|
|
_METHOD_PARAM = '_method'
|
|
_CONTENTTYPE_PARAM = '_content_type'
|
|
_CONTENT_PARAM = '_content'
|
|
|
|
"""
|
|
The set of request parsers that the view can handle.
|
|
|
|
Should be a tuple/list of classes as described in the :mod:`parsers` module.
|
|
"""
|
|
parsers = ()
|
|
|
|
@property
|
|
def method(self):
|
|
"""
|
|
Returns the HTTP method.
|
|
|
|
This should be used instead of just reading :const:`request.method`, as
|
|
it allows the `method` to be overridden by using a hidden `form` field
|
|
on a form POST request.
|
|
"""
|
|
if not hasattr(self, '_method'):
|
|
self._load_method_and_content_type()
|
|
return self._method
|
|
|
|
@property
|
|
def content_type(self):
|
|
"""
|
|
Returns the content type header.
|
|
|
|
This should be used instead of ``request.META.get('HTTP_CONTENT_TYPE')``,
|
|
as it allows the content type to be overridden by using a hidden form
|
|
field on a form POST request.
|
|
"""
|
|
if not hasattr(self, '_content_type'):
|
|
self._load_method_and_content_type()
|
|
return self._content_type
|
|
|
|
@property
|
|
def DATA(self):
|
|
"""
|
|
Parses the request body and returns the data.
|
|
|
|
Similar to ``request.POST``, except that it handles arbitrary parsers,
|
|
and also works on methods other than POST (eg PUT).
|
|
"""
|
|
if not hasattr(self, '_data'):
|
|
self._load_data_and_files()
|
|
return self._data
|
|
|
|
@property
|
|
def FILES(self):
|
|
"""
|
|
Parses the request body and returns the files.
|
|
Similar to ``request.FILES``, except that it handles arbitrary parsers,
|
|
and also works on methods other than POST (eg PUT).
|
|
"""
|
|
if not hasattr(self, '_files'):
|
|
self._load_data_and_files()
|
|
return self._files
|
|
|
|
def _load_data_and_files(self):
|
|
"""
|
|
Parse the request content into self.DATA and self.FILES.
|
|
"""
|
|
if not hasattr(self, '_content_type'):
|
|
self._load_method_and_content_type()
|
|
|
|
if not hasattr(self, '_data'):
|
|
(self._data, self._files) = self._parse(self._get_stream(),
|
|
self._content_type)
|
|
|
|
def _load_method_and_content_type(self):
|
|
"""
|
|
Set the method and content_type, and then check if they've been
|
|
overridden.
|
|
"""
|
|
self._method = self.request.method
|
|
self._content_type = self.request.META.get('HTTP_CONTENT_TYPE',
|
|
self.request.META.get('CONTENT_TYPE', ''))
|
|
self._perform_form_overloading()
|
|
|
|
def _get_stream(self):
|
|
"""
|
|
Returns an object that may be used to stream the request content.
|
|
"""
|
|
request = self.request
|
|
|
|
try:
|
|
content_length = int(request.META.get('CONTENT_LENGTH',
|
|
request.META.get('HTTP_CONTENT_LENGTH')))
|
|
except (ValueError, TypeError):
|
|
content_length = 0
|
|
|
|
# TODO: Add 1.3's LimitedStream to compat and use that.
|
|
# NOTE: Currently only supports parsing request body as a stream with 1.3
|
|
if content_length == 0:
|
|
return None
|
|
elif hasattr(request, 'read'):
|
|
return request
|
|
return StringIO(request.raw_post_data)
|
|
|
|
def _perform_form_overloading(self):
|
|
"""
|
|
If this is a form POST request, then we need to check if the method and
|
|
content/content_type have been overridden by setting them in hidden
|
|
form fields or not.
|
|
"""
|
|
|
|
# We only need to use form overloading on form POST requests.
|
|
if (not self._USE_FORM_OVERLOADING
|
|
or self._method != 'POST'
|
|
or not is_form_media_type(self._content_type)):
|
|
return
|
|
|
|
# At this point we're committed to parsing the request as form data.
|
|
self._data = data = self.request.POST.copy()
|
|
self._files = self.request.FILES
|
|
|
|
# Method overloading - change the method and remove the param from the content.
|
|
if self._METHOD_PARAM in data:
|
|
# NOTE: unlike `get`, `pop` on a `QueryDict` seems to return a list of values.
|
|
self._method = self._data.pop(self._METHOD_PARAM)[0].upper()
|
|
|
|
# Content overloading - modify the content type, and re-parse.
|
|
if self._CONTENT_PARAM in data and self._CONTENTTYPE_PARAM in data:
|
|
self._content_type = self._data.pop(self._CONTENTTYPE_PARAM)[0]
|
|
stream = StringIO(self._data.pop(self._CONTENT_PARAM)[0])
|
|
(self._data, self._files) = self._parse(stream, self._content_type)
|
|
|
|
def _parse(self, stream, content_type):
|
|
"""
|
|
Parse the request content.
|
|
|
|
May raise a 415 ErrorResponse (Unsupported Media Type), or a 400
|
|
ErrorResponse (Bad Request).
|
|
"""
|
|
if stream is None or content_type is None:
|
|
return (None, None)
|
|
|
|
for parser_cls in self.parsers:
|
|
parser = parser_cls(self)
|
|
if parser.can_handle_request(content_type):
|
|
return parser.parse(stream)
|
|
|
|
error = {'error':
|
|
"Unsupported media type in request '%s'." % content_type}
|
|
raise ErrorResponse(status.HTTP_415_UNSUPPORTED_MEDIA_TYPE, error)
|
|
|
|
@property
|
|
def _parsed_media_types(self):
|
|
"""
|
|
Return a list of all the media types that this view can parse.
|
|
"""
|
|
return [parser.media_type for parser in self.parsers]
|
|
|
|
@property
|
|
def _default_parser(self):
|
|
"""
|
|
Return the view's default parser class.
|
|
"""
|
|
return self.parsers[0]
|
|
|
|
|
|
########## ResponseMixin ##########
|
|
|
|
|
|
class ResponseMixin(object):
|
|
"""
|
|
Adds behavior for pluggable `Renderers` to a :class:`views.View` class.
|
|
|
|
Default behavior is to use standard HTTP Accept header content negotiation.
|
|
|
|
Also supports overriding the content type by specifying an ``_accept=``
|
|
parameter in the URL.
|
|
|
|
Ignores Accept headers from Internet Explorer user agents and uses a
|
|
sensible browser Accept header instead.
|
|
"""
|
|
|
|
# Allow override of Accept header in URL query params
|
|
_ACCEPT_QUERY_PARAM = '_accept'
|
|
_IGNORE_IE_ACCEPT_HEADER = True
|
|
|
|
"""
|
|
The set of response renderers that the view can handle.
|
|
|
|
Should be a tuple/list of classes as described in the :mod:`renderers`
|
|
module.
|
|
"""
|
|
renderers = ()
|
|
|
|
# TODO: wrap this behavior around dispatch(), ensuring it works
|
|
# out of the box with existing Django classes that use render_to_response.
|
|
def render(self, response):
|
|
"""
|
|
Takes a :obj:`Response` object and returns an :obj:`HttpResponse`.
|
|
"""
|
|
self.response = response
|
|
|
|
try:
|
|
renderer, media_type = self._determine_renderer(self.request)
|
|
except ErrorResponse, exc:
|
|
renderer = self._default_renderer(self)
|
|
media_type = renderer.media_type
|
|
response = exc.response
|
|
|
|
# Set the media type of the response
|
|
# Note that the renderer *could* override it in .render() if required.
|
|
response.media_type = renderer.media_type
|
|
|
|
# Serialize the response content
|
|
if response.has_content_body:
|
|
content = renderer.render(response.cleaned_content, media_type)
|
|
else:
|
|
content = renderer.render()
|
|
|
|
# Build the HTTP Response
|
|
resp = HttpResponse(content, mimetype=response.media_type,
|
|
status=response.status)
|
|
for (key, val) in response.headers.items():
|
|
resp[key] = val
|
|
|
|
return resp
|
|
|
|
def _determine_renderer(self, request):
|
|
"""
|
|
Determines the appropriate renderer for the output, given the client's
|
|
'Accept' header, and the :attr:`renderers` set on this class.
|
|
|
|
Returns a 2-tuple of `(renderer, media_type)`
|
|
|
|
See: RFC 2616, Section 14
|
|
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
|
|
"""
|
|
|
|
if (self._ACCEPT_QUERY_PARAM and
|
|
request.GET.get(self._ACCEPT_QUERY_PARAM, None)):
|
|
# Use _accept parameter override
|
|
accept_list = [request.GET.get(self._ACCEPT_QUERY_PARAM)]
|
|
|
|
elif (self._IGNORE_IE_ACCEPT_HEADER and
|
|
'HTTP_USER_AGENT' in request.META and
|
|
MSIE_USER_AGENT_REGEX.match(request.META['HTTP_USER_AGENT'])):
|
|
# Ignore MSIE's broken accept behavior and do something sensible
|
|
# instead.
|
|
accept_list = ['text/html', '*/*']
|
|
|
|
elif 'HTTP_ACCEPT' in request.META:
|
|
# Use standard HTTP Accept negotiation
|
|
accept_list = [token.strip() for token in
|
|
request.META['HTTP_ACCEPT'].split(',')]
|
|
|
|
else:
|
|
# No accept header specified
|
|
accept_list = ['*/*']
|
|
|
|
# Check the acceptable media types against each renderer,
|
|
# attempting more specific media types first
|
|
# NB. The inner loop here isn't as bad as it first looks :)
|
|
# Worst case is: len(accept_list) * len(self.renderers)
|
|
renderers = [renderer_cls(self) for renderer_cls in self.renderers]
|
|
|
|
for accepted_media_type_lst in order_by_precedence(accept_list):
|
|
for renderer in renderers:
|
|
for accepted_media_type in accepted_media_type_lst:
|
|
if renderer.can_handle_response(accepted_media_type):
|
|
return renderer, accepted_media_type
|
|
|
|
# No acceptable renderers were found
|
|
error = {'detail': "Could not satisfy the client's Accept header",
|
|
'available_types': self._rendered_media_types}
|
|
raise ErrorResponse(status.HTTP_406_NOT_ACCEPTABLE, error)
|
|
|
|
@property
|
|
def _rendered_media_types(self):
|
|
"""
|
|
Return an list of all the media types that this view can render.
|
|
"""
|
|
return [renderer.media_type for renderer in self.renderers]
|
|
|
|
@property
|
|
def _rendered_formats(self):
|
|
"""
|
|
Return a list of all the formats that this view can render.
|
|
"""
|
|
return [renderer.format for renderer in self.renderers]
|
|
|
|
@property
|
|
def _default_renderer(self):
|
|
"""
|
|
Return the view's default renderer class.
|
|
"""
|
|
return self.renderers[0]
|
|
|
|
|
|
########## Auth Mixin ##########
|
|
|
|
class AuthMixin(object):
|
|
"""
|
|
Simple :class:`mixin` class to add authentication and permission checking
|
|
to a :class:`View` class.
|
|
"""
|
|
|
|
"""
|
|
The set of authentication types that this view can handle.
|
|
|
|
Should be a tuple/list of classes as described in the :mod:`authentication`
|
|
module.
|
|
"""
|
|
authentication = ()
|
|
|
|
"""
|
|
The set of permissions that will be enforced on this view.
|
|
|
|
Should be a tuple/list of classes as described in the :mod:`permissions`
|
|
module.
|
|
"""
|
|
permissions = ()
|
|
|
|
@property
|
|
def user(self):
|
|
"""
|
|
Returns the :obj:`user` for the current request, as determined by the
|
|
set of :class:`authentication` classes applied to the :class:`View`.
|
|
"""
|
|
if not hasattr(self, '_user'):
|
|
self._user = self._authenticate()
|
|
return self._user
|
|
|
|
def _authenticate(self):
|
|
"""
|
|
Attempt to authenticate the request using each authentication class in
|
|
turn. Returns a ``User`` object, which may be ``AnonymousUser``.
|
|
"""
|
|
for authentication_cls in self.authentication:
|
|
authentication = authentication_cls(self)
|
|
user = authentication.authenticate(self.request)
|
|
if user:
|
|
return user
|
|
return AnonymousUser()
|
|
|
|
# TODO: wrap this behavior around dispatch()
|
|
def _check_permissions(self):
|
|
"""
|
|
Check user permissions and either raise an ``ErrorResponse`` or return.
|
|
"""
|
|
user = self.user
|
|
for permission_cls in self.permissions:
|
|
permission = permission_cls(self)
|
|
permission.check_permission(user)
|
|
|
|
|
|
########## Resource Mixin ##########
|
|
|
|
class ResourceMixin(object):
|
|
"""
|
|
Provides request validation and response filtering behavior.
|
|
|
|
Should be a class as described in the :mod:`resources` module.
|
|
|
|
The :obj:`resource` is an object that maps a view onto it's representation
|
|
on the server.
|
|
|
|
It provides validation on the content of incoming requests,
|
|
and filters the object representation into a serializable object for the
|
|
response.
|
|
"""
|
|
resource_class = None
|
|
|
|
@property
|
|
def CONTENT(self):
|
|
"""
|
|
Returns the cleaned, validated request content.
|
|
|
|
May raise an :class:`response.ErrorResponse` with status code 400
|
|
(Bad Request).
|
|
"""
|
|
if not hasattr(self, '_content'):
|
|
self._content = self.validate_request(self.DATA, self.FILES)
|
|
return self._content
|
|
|
|
@property
|
|
def PARAMS(self):
|
|
"""
|
|
Returns the cleaned, validated query parameters.
|
|
|
|
May raise an :class:`response.ErrorResponse` with status code 400
|
|
(Bad Request).
|
|
"""
|
|
return self.validate_request(self.request.GET)
|
|
|
|
@property
|
|
def _resource(self):
|
|
if self.resource_class:
|
|
return self.resource_class(self)
|
|
elif getattr(self, 'model', None):
|
|
return ModelResource(self)
|
|
elif getattr(self, 'form', None):
|
|
return FormResource(self)
|
|
elif getattr(self, '%s_form' % self.method.lower(), None):
|
|
return FormResource(self)
|
|
return Resource(self)
|
|
|
|
def validate_request(self, data, files=None):
|
|
"""
|
|
Given the request *data* and optional *files*, return the cleaned,
|
|
validated content.
|
|
May raise an :class:`response.ErrorResponse` with status code 400
|
|
(Bad Request) on failure.
|
|
"""
|
|
return self._resource.validate_request(data, files)
|
|
|
|
def filter_response(self, obj):
|
|
"""
|
|
Given the response content, filter it into a serializable object.
|
|
"""
|
|
return self._resource.filter_response(obj)
|
|
|
|
def get_bound_form(self, content=None, method=None):
|
|
if hasattr(self._resource, 'get_bound_form'):
|
|
return self._resource.get_bound_form(content, method=method)
|
|
else:
|
|
return None
|
|
|
|
|
|
##########
|
|
|
|
|
|
class InstanceMixin(object):
|
|
"""
|
|
`Mixin` class that is used to identify a `View` class as being the
|
|
canonical identifier for the resources it is mapped to.
|
|
"""
|
|
|
|
@classmethod
|
|
def as_view(cls, **initkwargs):
|
|
"""
|
|
Store the callable object on the resource class that has been
|
|
associated with this view.
|
|
"""
|
|
view = super(InstanceMixin, cls).as_view(**initkwargs)
|
|
resource = getattr(cls(**initkwargs), 'resource', None)
|
|
if resource:
|
|
# We do a little dance when we store the view callable...
|
|
# we need to store it wrapped in a 1-tuple, so that inspect will
|
|
# treat it as a function when we later look it up (rather than
|
|
# turning it into a method).
|
|
# This makes sure our URL reversing works ok.
|
|
resource.view_callable = (view,)
|
|
return view
|
|
|
|
|
|
########## Resource operation Mixins ##########
|
|
|
|
class ReadResourceMixin(object):
|
|
|
|
def get(self, request, *args, **kwargs):
|
|
try:
|
|
resource = self.resource_class.retrieve(request, *args, **kwargs)
|
|
except self.resource_class.DoesNotExist:
|
|
raise ErrorResponse(status.HTTP_404_NOT_FOUND)
|
|
return resource
|
|
|
|
|
|
class CreateResourceMixin(object):
|
|
|
|
def post(self, request, *args, **kwargs):
|
|
resource = self.resource_class.create(request, *args, **kwargs)
|
|
resource.update(self.CONTENT, request, *args, **kwargs)
|
|
headers = {'Location': resource.get_url()}
|
|
return Response(status.HTTP_201_CREATED, resource, headers)
|
|
|
|
|
|
class CreateSubResourceMixin(object):
|
|
|
|
def post(self, request, *args, **kwargs):
|
|
sub_resource = self.resource_class.create(request, *args, **kwargs)
|
|
sub_resource.update(self.CONTENT, request, *args, **kwargs)
|
|
headers = {'Location': sub_resource.get_url()}
|
|
return Response(status.HTTP_201_CREATED, sub_resource, headers)
|
|
|
|
|
|
class UpdateResourceMixin(object):
|
|
|
|
def put(self, request, *args, **kwargs):
|
|
headers = {}
|
|
try:
|
|
resource = self.resource_class.retrieve(request, *args, **kwargs)
|
|
status_code = status.HTTP_204_NO_CONTENT
|
|
except self.resource_class.DoesNotExist:
|
|
resource = self.resource_class.create(request, *args, **kwargs)
|
|
status_code = status.HTTP_201_CREATED
|
|
resource.update(self.CONTENT, request, *args, **kwargs)
|
|
return Response(status_code, resource, {})
|
|
|
|
|
|
class DeleteResourceMixin(object):
|
|
|
|
def delete(self, request, *args, **kwargs):
|
|
try:
|
|
resource = self.resource_class.retrieve(request, *args, **kwargs)
|
|
except self.resource_class.DoesNotExist:
|
|
raise ErrorResponse(status.HTTP_404_NOT_FOUND)
|
|
resource.delete(request, *args, **kwargs)
|
|
return
|
|
|
|
|
|
########## Pagination Mixins ##########
|
|
|
|
class PaginatorMixin(object):
|
|
"""
|
|
Adds pagination support to GET requests
|
|
Obviously should only be used on lists :)
|
|
|
|
A default limit can be set by setting `limit` on the object. This will also
|
|
be used as the maximum if the client sets the `limit` GET param
|
|
"""
|
|
limit = 20
|
|
|
|
def get_limit(self):
|
|
""" Helper method to determine what the `limit` should be """
|
|
try:
|
|
limit = int(self.request.GET.get('limit', self.limit))
|
|
return min(limit, self.limit)
|
|
except ValueError:
|
|
return self.limit
|
|
|
|
def url_with_page_number(self, page_number):
|
|
"""Constructs a url used for getting the next/previous urls."""
|
|
url = "%s?page=%d" % (self.request.path, page_number)
|
|
|
|
limit = self.get_limit()
|
|
if limit != self.limit:
|
|
url = "%s&limit=%d" % (url, limit)
|
|
|
|
return url
|
|
|
|
def next(self, page):
|
|
"""Returns a url to the next page of results. (If any exists.)"""
|
|
if not page.has_next():
|
|
return None
|
|
|
|
return self.url_with_page_number(page.next_page_number())
|
|
|
|
def previous(self, page):
|
|
"""Returns a url to the previous page of results. (If any exists.)"""
|
|
if not page.has_previous():
|
|
return None
|
|
|
|
return self.url_with_page_number(page.previous_page_number())
|
|
|
|
def serialize_page_info(self, page):
|
|
"""This is some useful information that is added to the response."""
|
|
return {
|
|
'next': self.next(page),
|
|
'page': page.number,
|
|
'pages': page.paginator.num_pages,
|
|
'per_page': self.get_limit(),
|
|
'previous': self.previous(page),
|
|
'total': page.paginator.count,
|
|
}
|
|
|
|
def filter_response(self, obj):
|
|
"""
|
|
Given the response content, paginate and then serialize.
|
|
|
|
The response is modified to include to useful data relating to the
|
|
number of objects, number of pages, next/previous urls etc. etc.
|
|
|
|
The serialised objects are put into `results` on this new, modified
|
|
response
|
|
"""
|
|
|
|
# We don't want to paginate responses for anything other than GET
|
|
# requests
|
|
if self.method.upper() != 'GET':
|
|
return self._resource.filter_response(obj)
|
|
|
|
paginator = Paginator(obj, self.get_limit())
|
|
|
|
try:
|
|
page_num = int(self.request.GET.get('page', '1'))
|
|
except ValueError:
|
|
raise ErrorResponse(status.HTTP_404_NOT_FOUND,
|
|
{'detail': 'That page contains no results'})
|
|
|
|
if page_num not in paginator.page_range:
|
|
raise ErrorResponse(status.HTTP_404_NOT_FOUND,
|
|
{'detail': 'That page contains no results'})
|
|
|
|
page = paginator.page(page_num)
|
|
|
|
serialized_object_list = self._resource.filter_response(page.object_list)
|
|
serialized_page_info = self.serialize_page_info(page)
|
|
|
|
serialized_page_info['results'] = serialized_object_list
|
|
|
|
return serialized_page_info
|