datatracker/tastypie/resources.py

2450 lines
91 KiB
Python

from __future__ import unicode_literals
from __future__ import with_statement
from copy import deepcopy
import logging
import warnings
from django.conf import settings
from django.conf.urls import patterns, url
from django.core.exceptions import ObjectDoesNotExist, MultipleObjectsReturned, ValidationError
from django.core.urlresolvers import NoReverseMatch, reverse, resolve, Resolver404, get_script_prefix
from django.core.signals import got_request_exception
from django.db import transaction
from django.db.models.constants import LOOKUP_SEP
from django.db.models.sql.constants import QUERY_TERMS
from django.http import HttpResponse, HttpResponseNotFound, Http404
from django.utils.cache import patch_cache_control, patch_vary_headers
from django.utils.html import escape
from django.utils import six
from tastypie.authentication import Authentication
from tastypie.authorization import ReadOnlyAuthorization
from tastypie.bundle import Bundle
from tastypie.cache import NoCache
from tastypie.constants import ALL, ALL_WITH_RELATIONS
from tastypie.exceptions import NotFound, BadRequest, InvalidFilterError, HydrationError, InvalidSortError, ImmediateHttpResponse, Unauthorized
from tastypie import fields
from tastypie import http
from tastypie.paginator import Paginator
from tastypie.serializers import Serializer
from tastypie.throttle import BaseThrottle
from tastypie.utils import is_valid_jsonp_callback_value, dict_strip_unicode_keys, trailing_slash
from tastypie.utils.mime import determine_format, build_content_type
from tastypie.validation import Validation
# If ``csrf_exempt`` isn't present, stub it.
try:
from django.views.decorators.csrf import csrf_exempt
except ImportError:
def csrf_exempt(func):
return func
def sanitize(text):
# We put the single quotes back, due to their frequent usage in exception
# messages.
return escape(text).replace(''', "'").replace('"', '"')
class NOT_AVAILABLE:
def __str__(self):
return 'No such data is available.'
class ResourceOptions(object):
"""
A configuration class for ``Resource``.
Provides sane defaults and the logic needed to augment these settings with
the internal ``class Meta`` used on ``Resource`` subclasses.
"""
serializer = Serializer()
authentication = Authentication()
authorization = ReadOnlyAuthorization()
cache = NoCache()
throttle = BaseThrottle()
validation = Validation()
paginator_class = Paginator
allowed_methods = ['get', 'post', 'put', 'delete', 'patch']
list_allowed_methods = None
detail_allowed_methods = None
limit = getattr(settings, 'API_LIMIT_PER_PAGE', 20)
max_limit = 1000
api_name = None
resource_name = None
urlconf_namespace = None
default_format = 'application/json'
filtering = {}
ordering = []
object_class = None
queryset = None
fields = []
excludes = []
include_resource_uri = True
include_absolute_url = False
always_return_data = False
collection_name = 'objects'
detail_uri_name = 'pk'
def __new__(cls, meta=None):
overrides = {}
# Handle overrides.
if meta:
for override_name in dir(meta):
# No internals please.
if not override_name.startswith('_'):
overrides[override_name] = getattr(meta, override_name)
allowed_methods = overrides.get('allowed_methods', ['get', 'post', 'put', 'delete', 'patch'])
if overrides.get('list_allowed_methods', None) is None:
overrides['list_allowed_methods'] = allowed_methods
if overrides.get('detail_allowed_methods', None) is None:
overrides['detail_allowed_methods'] = allowed_methods
if six.PY3:
return object.__new__(type('ResourceOptions', (cls,), overrides))
else:
return object.__new__(type(b'ResourceOptions', (cls,), overrides))
class DeclarativeMetaclass(type):
def __new__(cls, name, bases, attrs):
attrs['base_fields'] = {}
declared_fields = {}
# Inherit any fields from parent(s).
try:
parents = [b for b in bases if issubclass(b, Resource)]
# Simulate the MRO.
parents.reverse()
for p in parents:
parent_fields = getattr(p, 'base_fields', {})
for field_name, field_object in parent_fields.items():
attrs['base_fields'][field_name] = deepcopy(field_object)
except NameError:
pass
for field_name, obj in attrs.copy().items():
# Look for ``dehydrated_type`` instead of doing ``isinstance``,
# which can break down if Tastypie is re-namespaced as something
# else.
if hasattr(obj, 'dehydrated_type'):
field = attrs.pop(field_name)
declared_fields[field_name] = field
attrs['base_fields'].update(declared_fields)
attrs['declared_fields'] = declared_fields
new_class = super(DeclarativeMetaclass, cls).__new__(cls, name, bases, attrs)
opts = getattr(new_class, 'Meta', None)
new_class._meta = ResourceOptions(opts)
if not getattr(new_class._meta, 'resource_name', None):
# No ``resource_name`` provided. Attempt to auto-name the resource.
class_name = new_class.__name__
name_bits = [bit for bit in class_name.split('Resource') if bit]
resource_name = ''.join(name_bits).lower()
new_class._meta.resource_name = resource_name
if getattr(new_class._meta, 'include_resource_uri', True):
if not 'resource_uri' in new_class.base_fields:
new_class.base_fields['resource_uri'] = fields.CharField(readonly=True)
elif 'resource_uri' in new_class.base_fields and not 'resource_uri' in attrs:
del(new_class.base_fields['resource_uri'])
for field_name, field_object in new_class.base_fields.items():
if hasattr(field_object, 'contribute_to_class'):
field_object.contribute_to_class(new_class, field_name)
return new_class
class Resource(six.with_metaclass(DeclarativeMetaclass)):
"""
Handles the data, request dispatch and responding to requests.
Serialization/deserialization is handled "at the edges" (i.e. at the
beginning/end of the request/response cycle) so that everything internally
is Python data structures.
This class tries to be non-model specific, so it can be hooked up to other
data sources, such as search results, files, other data, etc.
"""
def __init__(self, api_name=None):
self.fields = deepcopy(self.base_fields)
if not api_name is None:
self._meta.api_name = api_name
def __getattr__(self, name):
if name in self.fields:
return self.fields[name]
raise AttributeError(name)
def wrap_view(self, view):
"""
Wraps methods so they can be called in a more functional way as well
as handling exceptions better.
Note that if ``BadRequest`` or an exception with a ``response`` attr
are seen, there is special handling to either present a message back
to the user or return the response traveling with the exception.
"""
@csrf_exempt
def wrapper(request, *args, **kwargs):
try:
callback = getattr(self, view)
response = callback(request, *args, **kwargs)
# Our response can vary based on a number of factors, use
# the cache class to determine what we should ``Vary`` on so
# caches won't return the wrong (cached) version.
varies = getattr(self._meta.cache, "varies", [])
if varies:
patch_vary_headers(response, varies)
if self._meta.cache.cacheable(request, response):
if self._meta.cache.cache_control():
# If the request is cacheable and we have a
# ``Cache-Control`` available then patch the header.
patch_cache_control(response, **self._meta.cache.cache_control())
if request.is_ajax() and not response.has_header("Cache-Control"):
# IE excessively caches XMLHttpRequests, so we're disabling
# the browser cache here.
# See http://www.enhanceie.com/ie/bugs.asp for details.
patch_cache_control(response, no_cache=True)
return response
except (BadRequest, fields.ApiFieldError) as e:
data = {"error": sanitize(e.args[0]) if getattr(e, 'args') else ''}
return self.error_response(request, data, response_class=http.HttpBadRequest)
except ValidationError as e:
data = {"error": sanitize(e.messages)}
return self.error_response(request, data, response_class=http.HttpBadRequest)
except Exception as e:
if hasattr(e, 'response'):
return e.response
# A real, non-expected exception.
# Handle the case where the full traceback is more helpful
# than the serialized error.
if settings.DEBUG and getattr(settings, 'TASTYPIE_FULL_DEBUG', False):
raise
# Re-raise the error to get a proper traceback when the error
# happend during a test case
if request.META.get('SERVER_NAME') == 'testserver':
raise
# Rather than re-raising, we're going to things similar to
# what Django does. The difference is returning a serialized
# error message.
return self._handle_500(request, e)
return wrapper
def _handle_500(self, request, exception):
import traceback
import sys
the_trace = '\n'.join(traceback.format_exception(*(sys.exc_info())))
response_class = http.HttpApplicationError
response_code = 500
NOT_FOUND_EXCEPTIONS = (NotFound, ObjectDoesNotExist, Http404)
if isinstance(exception, NOT_FOUND_EXCEPTIONS):
response_class = HttpResponseNotFound
response_code = 404
if settings.DEBUG:
data = {
"error_message": sanitize(six.text_type(exception)),
"traceback": the_trace,
}
return self.error_response(request, data, response_class=response_class)
# When DEBUG is False, send an error message to the admins (unless it's
# a 404, in which case we check the setting).
send_broken_links = getattr(settings, 'SEND_BROKEN_LINK_EMAILS', False)
if not response_code == 404 or send_broken_links:
log = logging.getLogger('django.request.tastypie')
log.error('Internal Server Error: %s' % request.path, exc_info=True,
extra={'status_code': response_code, 'request': request})
# Send the signal so other apps are aware of the exception.
got_request_exception.send(self.__class__, request=request)
# Prep the data going out.
data = {
"error_message": getattr(settings, 'TASTYPIE_CANNED_ERROR', "Sorry, this request could not be processed. Please try again later."),
}
return self.error_response(request, data, response_class=response_class)
def _build_reverse_url(self, name, args=None, kwargs=None):
"""
A convenience hook for overriding how URLs are built.
See ``NamespacedModelResource._build_reverse_url`` for an example.
"""
return reverse(name, args=args, kwargs=kwargs)
def base_urls(self):
"""
The standard URLs this ``Resource`` should respond to.
"""
return [
url(r"^(?P<resource_name>%s)%s$" % (self._meta.resource_name, trailing_slash()), self.wrap_view('dispatch_list'), name="api_dispatch_list"),
url(r"^(?P<resource_name>%s)/schema%s$" % (self._meta.resource_name, trailing_slash()), self.wrap_view('get_schema'), name="api_get_schema"),
url(r"^(?P<resource_name>%s)/set/(?P<%s_list>.*?)%s$" % (self._meta.resource_name, self._meta.detail_uri_name, trailing_slash()), self.wrap_view('get_multiple'), name="api_get_multiple"),
url(r"^(?P<resource_name>%s)/(?P<%s>.*?)%s$" % (self._meta.resource_name, self._meta.detail_uri_name, trailing_slash()), self.wrap_view('dispatch_detail'), name="api_dispatch_detail"),
]
def override_urls(self):
"""
Deprecated. Will be removed by v1.0.0. Please use ``prepend_urls`` instead.
"""
return []
def prepend_urls(self):
"""
A hook for adding your own URLs or matching before the default URLs.
"""
return []
@property
def urls(self):
"""
The endpoints this ``Resource`` responds to.
Mostly a standard URLconf, this is suitable for either automatic use
when registered with an ``Api`` class or for including directly in
a URLconf should you choose to.
"""
urls = self.prepend_urls()
overridden_urls = self.override_urls()
if overridden_urls:
warnings.warn("'override_urls' is a deprecated method & will be removed by v1.0.0. Please rename your method to ``prepend_urls``.")
urls += overridden_urls
urls += self.base_urls()
urlpatterns = patterns('',
*urls
)
return urlpatterns
def determine_format(self, request):
"""
Used to determine the desired format.
Largely relies on ``tastypie.utils.mime.determine_format`` but here
as a point of extension.
"""
return determine_format(request, self._meta.serializer, default_format=self._meta.default_format)
def serialize(self, request, data, format, options=None):
"""
Given a request, data and a desired format, produces a serialized
version suitable for transfer over the wire.
Mostly a hook, this uses the ``Serializer`` from ``Resource._meta``.
"""
options = options or {}
if 'text/javascript' in format:
# get JSONP callback name. default to "callback"
callback = request.GET.get('callback', 'callback')
if not is_valid_jsonp_callback_value(callback):
raise BadRequest('JSONP callback name is invalid.')
options['callback'] = callback
return self._meta.serializer.serialize(data, format, options)
def deserialize(self, request, data, format='application/json'):
"""
Given a request, data and a format, deserializes the given data.
It relies on the request properly sending a ``CONTENT_TYPE`` header,
falling back to ``application/json`` if not provided.
Mostly a hook, this uses the ``Serializer`` from ``Resource._meta``.
"""
deserialized = self._meta.serializer.deserialize(data, format=request.META.get('CONTENT_TYPE', 'application/json'))
return deserialized
def alter_list_data_to_serialize(self, request, data):
"""
A hook to alter list data just before it gets serialized & sent to the user.
Useful for restructuring/renaming aspects of the what's going to be
sent.
Should accommodate for a list of objects, generally also including
meta data.
"""
return data
def alter_detail_data_to_serialize(self, request, data):
"""
A hook to alter detail data just before it gets serialized & sent to the user.
Useful for restructuring/renaming aspects of the what's going to be
sent.
Should accommodate for receiving a single bundle of data.
"""
return data
def alter_deserialized_list_data(self, request, data):
"""
A hook to alter list data just after it has been received from the user &
gets deserialized.
Useful for altering the user data before any hydration is applied.
"""
return data
def alter_deserialized_detail_data(self, request, data):
"""
A hook to alter detail data just after it has been received from the user &
gets deserialized.
Useful for altering the user data before any hydration is applied.
"""
return data
def dispatch_list(self, request, **kwargs):
"""
A view for handling the various HTTP methods (GET/POST/PUT/DELETE) over
the entire list of resources.
Relies on ``Resource.dispatch`` for the heavy-lifting.
"""
return self.dispatch('list', request, **kwargs)
def dispatch_detail(self, request, **kwargs):
"""
A view for handling the various HTTP methods (GET/POST/PUT/DELETE) on
a single resource.
Relies on ``Resource.dispatch`` for the heavy-lifting.
"""
return self.dispatch('detail', request, **kwargs)
def dispatch(self, request_type, request, **kwargs):
"""
Handles the common operations (allowed HTTP method, authentication,
throttling, method lookup) surrounding most CRUD interactions.
"""
allowed_methods = getattr(self._meta, "%s_allowed_methods" % request_type, None)
if 'HTTP_X_HTTP_METHOD_OVERRIDE' in request.META:
request.method = request.META['HTTP_X_HTTP_METHOD_OVERRIDE']
request_method = self.method_check(request, allowed=allowed_methods)
method = getattr(self, "%s_%s" % (request_method, request_type), None)
if method is None:
raise ImmediateHttpResponse(response=http.HttpNotImplemented())
self.is_authenticated(request)
self.throttle_check(request)
# All clear. Process the request.
request = convert_post_to_put(request)
response = method(request, **kwargs)
# Add the throttled request.
self.log_throttled_access(request)
# If what comes back isn't a ``HttpResponse``, assume that the
# request was accepted and that some action occurred. This also
# prevents Django from freaking out.
if not isinstance(response, HttpResponse):
return http.HttpNoContent()
return response
def remove_api_resource_names(self, url_dict):
"""
Given a dictionary of regex matches from a URLconf, removes
``api_name`` and/or ``resource_name`` if found.
This is useful for converting URLconf matches into something suitable
for data lookup. For example::
Model.objects.filter(**self.remove_api_resource_names(matches))
"""
kwargs_subset = url_dict.copy()
for key in ['api_name', 'resource_name']:
try:
del(kwargs_subset[key])
except KeyError:
pass
return kwargs_subset
def method_check(self, request, allowed=None):
"""
Ensures that the HTTP method used on the request is allowed to be
handled by the resource.
Takes an ``allowed`` parameter, which should be a list of lowercase
HTTP methods to check against. Usually, this looks like::
# The most generic lookup.
self.method_check(request, self._meta.allowed_methods)
# A lookup against what's allowed for list-type methods.
self.method_check(request, self._meta.list_allowed_methods)
# A useful check when creating a new endpoint that only handles
# GET.
self.method_check(request, ['get'])
"""
if allowed is None:
allowed = []
request_method = request.method.lower()
allows = ','.join([meth.upper() for meth in allowed])
if request_method == "options":
response = HttpResponse(allows)
response['Allow'] = allows
raise ImmediateHttpResponse(response=response)
if not request_method in allowed:
response = http.HttpMethodNotAllowed(allows)
response['Allow'] = allows
raise ImmediateHttpResponse(response=response)
return request_method
def is_authenticated(self, request):
"""
Handles checking if the user is authenticated and dealing with
unauthenticated users.
Mostly a hook, this uses class assigned to ``authentication`` from
``Resource._meta``.
"""
# Authenticate the request as needed.
auth_result = self._meta.authentication.is_authenticated(request)
if isinstance(auth_result, HttpResponse):
raise ImmediateHttpResponse(response=auth_result)
if not auth_result is True:
raise ImmediateHttpResponse(response=http.HttpUnauthorized())
def throttle_check(self, request):
"""
Handles checking if the user should be throttled.
Mostly a hook, this uses class assigned to ``throttle`` from
``Resource._meta``.
"""
identifier = self._meta.authentication.get_identifier(request)
# Check to see if they should be throttled.
if self._meta.throttle.should_be_throttled(identifier):
# Throttle limit exceeded.
raise ImmediateHttpResponse(response=http.HttpTooManyRequests())
def log_throttled_access(self, request):
"""
Handles the recording of the user's access for throttling purposes.
Mostly a hook, this uses class assigned to ``throttle`` from
``Resource._meta``.
"""
request_method = request.method.lower()
self._meta.throttle.accessed(self._meta.authentication.get_identifier(request), url=request.get_full_path(), request_method=request_method)
def unauthorized_result(self, exception):
raise ImmediateHttpResponse(response=http.HttpUnauthorized())
def authorized_read_list(self, object_list, bundle):
"""
Handles checking of permissions to see if the user has authorization
to GET this resource.
"""
try:
auth_result = self._meta.authorization.read_list(object_list, bundle)
except Unauthorized as e:
self.unauthorized_result(e)
return auth_result
def authorized_read_detail(self, object_list, bundle):
"""
Handles checking of permissions to see if the user has authorization
to GET this resource.
"""
try:
auth_result = self._meta.authorization.read_detail(object_list, bundle)
if not auth_result is True:
raise Unauthorized()
except Unauthorized as e:
self.unauthorized_result(e)
return auth_result
def authorized_create_list(self, object_list, bundle):
"""
Handles checking of permissions to see if the user has authorization
to POST this resource.
"""
try:
auth_result = self._meta.authorization.create_list(object_list, bundle)
except Unauthorized as e:
self.unauthorized_result(e)
return auth_result
def authorized_create_detail(self, object_list, bundle):
"""
Handles checking of permissions to see if the user has authorization
to POST this resource.
"""
try:
auth_result = self._meta.authorization.create_detail(object_list, bundle)
if not auth_result is True:
raise Unauthorized()
except Unauthorized as e:
self.unauthorized_result(e)
return auth_result
def authorized_update_list(self, object_list, bundle):
"""
Handles checking of permissions to see if the user has authorization
to PUT this resource.
"""
try:
auth_result = self._meta.authorization.update_list(object_list, bundle)
except Unauthorized as e:
self.unauthorized_result(e)
return auth_result
def authorized_update_detail(self, object_list, bundle):
"""
Handles checking of permissions to see if the user has authorization
to PUT this resource.
"""
try:
auth_result = self._meta.authorization.update_detail(object_list, bundle)
if not auth_result is True:
raise Unauthorized()
except Unauthorized as e:
self.unauthorized_result(e)
return auth_result
def authorized_delete_list(self, object_list, bundle):
"""
Handles checking of permissions to see if the user has authorization
to DELETE this resource.
"""
try:
auth_result = self._meta.authorization.delete_list(object_list, bundle)
except Unauthorized as e:
self.unauthorized_result(e)
return auth_result
def authorized_delete_detail(self, object_list, bundle):
"""
Handles checking of permissions to see if the user has authorization
to DELETE this resource.
"""
try:
auth_result = self._meta.authorization.delete_detail(object_list, bundle)
if not auth_result:
raise Unauthorized()
except Unauthorized as e:
self.unauthorized_result(e)
return auth_result
def build_bundle(self, obj=None, data=None, request=None, objects_saved=None):
"""
Given either an object, a data dictionary or both, builds a ``Bundle``
for use throughout the ``dehydrate/hydrate`` cycle.
If no object is provided, an empty object from
``Resource._meta.object_class`` is created so that attempts to access
``bundle.obj`` do not fail.
"""
if obj is None and self._meta.object_class:
obj = self._meta.object_class()
return Bundle(
obj=obj,
data=data,
request=request,
objects_saved=objects_saved
)
def build_filters(self, filters=None):
"""
Allows for the filtering of applicable objects.
This needs to be implemented at the user level.'
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
return filters
def apply_sorting(self, obj_list, options=None):
"""
Allows for the sorting of objects being returned.
This needs to be implemented at the user level.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
return obj_list
def get_bundle_detail_data(self, bundle):
"""
Convenience method to return the ``detail_uri_name`` attribute off
``bundle.obj``.
Usually just accesses ``bundle.obj.pk`` by default.
"""
return getattr(bundle.obj, self._meta.detail_uri_name)
# URL-related methods.
def detail_uri_kwargs(self, bundle_or_obj):
"""
This needs to be implemented at the user level.
Given a ``Bundle`` or an object, it returns the extra kwargs needed to
generate a detail URI.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
def resource_uri_kwargs(self, bundle_or_obj=None):
"""
Builds a dictionary of kwargs to help generate URIs.
Automatically provides the ``Resource.Meta.resource_name`` (and
optionally the ``Resource.Meta.api_name`` if populated by an ``Api``
object).
If the ``bundle_or_obj`` argument is provided, it calls
``Resource.detail_uri_kwargs`` for additional bits to create
"""
kwargs = {
'resource_name': self._meta.resource_name,
}
if self._meta.api_name is not None:
kwargs['api_name'] = self._meta.api_name
if bundle_or_obj is not None:
kwargs.update(self.detail_uri_kwargs(bundle_or_obj))
return kwargs
def get_resource_uri(self, bundle_or_obj=None, url_name='api_dispatch_list'):
"""
Handles generating a resource URI.
If the ``bundle_or_obj`` argument is not provided, it builds the URI
for the list endpoint.
If the ``bundle_or_obj`` argument is provided, it builds the URI for
the detail endpoint.
Return the generated URI. If that URI can not be reversed (not found
in the URLconf), it will return an empty string.
"""
if bundle_or_obj is not None:
url_name = 'api_dispatch_detail'
try:
return self._build_reverse_url(url_name, kwargs=self.resource_uri_kwargs(bundle_or_obj))
except NoReverseMatch:
return ''
def get_via_uri(self, uri, request=None):
"""
This pulls apart the salient bits of the URI and populates the
resource via a ``obj_get``.
Optionally accepts a ``request``.
If you need custom behavior based on other portions of the URI,
simply override this method.
"""
prefix = get_script_prefix()
chomped_uri = uri
if prefix and chomped_uri.startswith(prefix):
chomped_uri = chomped_uri[len(prefix)-1:]
# We mangle the path a bit further & run URL resolution against *only*
# the current class. This ought to prevent bad URLs from resolving to
# incorrect data.
found_at = chomped_uri.rfind(self._meta.resource_name)
if found_at == -1:
raise NotFound("An incorrect URL was provided '%s' for the '%s' resource." % (uri, self.__class__.__name__))
chomped_uri = chomped_uri[found_at:]
try:
for url_resolver in getattr(self, 'urls', []):
result = url_resolver.resolve(chomped_uri)
if result is not None:
view, args, kwargs = result
break
else:
raise Resolver404("URI not found in 'self.urls'.")
except Resolver404:
raise NotFound("The URL provided '%s' was not a link to a valid resource." % uri)
bundle = self.build_bundle(request=request)
return self.obj_get(bundle=bundle, **self.remove_api_resource_names(kwargs))
# Data preparation.
def full_dehydrate(self, bundle, for_list=False):
"""
Given a bundle with an object instance, extract the information from it
to populate the resource.
"""
use_in = ['all', 'list' if for_list else 'detail']
# Dehydrate each field.
for field_name, field_object in self.fields.items():
# If it's not for use in this mode, skip
field_use_in = getattr(field_object, 'use_in', 'all')
if callable(field_use_in):
if not field_use_in(bundle):
continue
else:
if field_use_in not in use_in:
continue
# A touch leaky but it makes URI resolution work.
if getattr(field_object, 'dehydrated_type', None) == 'related':
field_object.api_name = self._meta.api_name
field_object.resource_name = self._meta.resource_name
bundle.data[field_name] = field_object.dehydrate(bundle, for_list=for_list)
# Check for an optional method to do further dehydration.
method = getattr(self, "dehydrate_%s" % field_name, None)
if method:
bundle.data[field_name] = method(bundle)
bundle = self.dehydrate(bundle)
return bundle
def dehydrate(self, bundle):
"""
A hook to allow a final manipulation of data once all fields/methods
have built out the dehydrated data.
Useful if you need to access more than one dehydrated field or want
to annotate on additional data.
Must return the modified bundle.
"""
return bundle
def full_hydrate(self, bundle):
"""
Given a populated bundle, distill it and turn it back into
a full-fledged object instance.
"""
if bundle.obj is None:
bundle.obj = self._meta.object_class()
bundle = self.hydrate(bundle)
for field_name, field_object in self.fields.items():
if field_object.readonly is True:
continue
# Check for an optional method to do further hydration.
method = getattr(self, "hydrate_%s" % field_name, None)
if method:
bundle = method(bundle)
if field_object.attribute:
value = field_object.hydrate(bundle)
# NOTE: We only get back a bundle when it is related field.
if isinstance(value, Bundle) and value.errors.get(field_name):
bundle.errors[field_name] = value.errors[field_name]
if value is not None or field_object.null:
# We need to avoid populating M2M data here as that will
# cause things to blow up.
if not getattr(field_object, 'is_related', False):
setattr(bundle.obj, field_object.attribute, value)
elif not getattr(field_object, 'is_m2m', False):
if value is not None:
# NOTE: A bug fix in Django (ticket #18153) fixes incorrect behavior
# which Tastypie was relying on. To fix this, we store value.obj to
# be saved later in save_related.
try:
setattr(bundle.obj, field_object.attribute, value.obj)
except (ValueError, ObjectDoesNotExist):
bundle.related_objects_to_save[field_object.attribute] = value.obj
elif field_object.blank:
continue
elif field_object.null:
setattr(bundle.obj, field_object.attribute, value)
return bundle
def hydrate(self, bundle):
"""
A hook to allow an initial manipulation of data before all methods/fields
have built out the hydrated data.
Useful if you need to access more than one hydrated field or want
to annotate on additional data.
Must return the modified bundle.
"""
return bundle
def hydrate_m2m(self, bundle):
"""
Populate the ManyToMany data on the instance.
"""
if bundle.obj is None:
raise HydrationError("You must call 'full_hydrate' before attempting to run 'hydrate_m2m' on %r." % self)
for field_name, field_object in self.fields.items():
if not getattr(field_object, 'is_m2m', False):
continue
if field_object.attribute:
# Note that we only hydrate the data, leaving the instance
# unmodified. It's up to the user's code to handle this.
# The ``ModelResource`` provides a working baseline
# in this regard.
bundle.data[field_name] = field_object.hydrate_m2m(bundle)
for field_name, field_object in self.fields.items():
if not getattr(field_object, 'is_m2m', False):
continue
method = getattr(self, "hydrate_%s" % field_name, None)
if method:
method(bundle)
return bundle
def build_schema(self):
"""
Returns a dictionary of all the fields on the resource and some
properties about those fields.
Used by the ``schema/`` endpoint to describe what will be available.
"""
data = {
'fields': {},
'default_format': self._meta.default_format,
'allowed_list_http_methods': self._meta.list_allowed_methods,
'allowed_detail_http_methods': self._meta.detail_allowed_methods,
'default_limit': self._meta.limit,
}
if self._meta.ordering:
data['ordering'] = self._meta.ordering
if self._meta.filtering:
data['filtering'] = self._meta.filtering
for field_name, field_object in self.fields.items():
data['fields'][field_name] = {
'default': field_object.default,
'type': field_object.dehydrated_type,
'nullable': field_object.null,
'blank': field_object.blank,
'readonly': field_object.readonly,
'help_text': field_object.help_text,
'unique': field_object.unique,
}
if field_object.dehydrated_type == 'related':
if getattr(field_object, 'is_m2m', False):
related_type = 'to_many'
else:
related_type = 'to_one'
data['fields'][field_name]['related_type'] = related_type
return data
def dehydrate_resource_uri(self, bundle):
"""
For the automatically included ``resource_uri`` field, dehydrate
the URI for the given bundle.
Returns empty string if no URI can be generated.
"""
try:
return self.get_resource_uri(bundle)
except NotImplementedError:
return ''
except NoReverseMatch:
return ''
def generate_cache_key(self, *args, **kwargs):
"""
Creates a unique-enough cache key.
This is based off the current api_name/resource_name/args/kwargs.
"""
smooshed = []
for key, value in kwargs.items():
smooshed.append("%s=%s" % (key, value))
# Use a list plus a ``.join()`` because it's faster than concatenation.
return "%s:%s:%s:%s" % (self._meta.api_name, self._meta.resource_name, ':'.join(args), ':'.join(sorted(smooshed)))
# Data access methods.
def get_object_list(self, request):
"""
A hook to allow making returning the list of available objects.
This needs to be implemented at the user level.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
def apply_authorization_limits(self, request, object_list):
"""
Deprecated.
FIXME: REMOVE BEFORE 1.0
"""
return self._meta.authorization.apply_limits(request, object_list)
def can_create(self):
"""
Checks to ensure ``post`` is within ``allowed_methods``.
"""
allowed = set(self._meta.list_allowed_methods + self._meta.detail_allowed_methods)
return 'post' in allowed
def can_update(self):
"""
Checks to ensure ``put`` is within ``allowed_methods``.
Used when hydrating related data.
"""
allowed = set(self._meta.list_allowed_methods + self._meta.detail_allowed_methods)
return 'put' in allowed
def can_delete(self):
"""
Checks to ensure ``delete`` is within ``allowed_methods``.
"""
allowed = set(self._meta.list_allowed_methods + self._meta.detail_allowed_methods)
return 'delete' in allowed
def apply_filters(self, request, applicable_filters):
"""
A hook to alter how the filters are applied to the object list.
This needs to be implemented at the user level.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
def obj_get_list(self, bundle, **kwargs):
"""
Fetches the list of objects available on the resource.
This needs to be implemented at the user level.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
def cached_obj_get_list(self, bundle, **kwargs):
"""
A version of ``obj_get_list`` that uses the cache as a means to get
commonly-accessed data faster.
"""
cache_key = self.generate_cache_key('list', **kwargs)
obj_list = self._meta.cache.get(cache_key)
if obj_list is None:
obj_list = self.obj_get_list(bundle=bundle, **kwargs)
self._meta.cache.set(cache_key, obj_list)
return obj_list
def obj_get(self, bundle, **kwargs):
"""
Fetches an individual object on the resource.
This needs to be implemented at the user level. If the object can not
be found, this should raise a ``NotFound`` exception.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
def cached_obj_get(self, bundle, **kwargs):
"""
A version of ``obj_get`` that uses the cache as a means to get
commonly-accessed data faster.
"""
cache_key = self.generate_cache_key('detail', **kwargs)
cached_bundle = self._meta.cache.get(cache_key)
if cached_bundle is None:
cached_bundle = self.obj_get(bundle=bundle, **kwargs)
self._meta.cache.set(cache_key, cached_bundle)
return cached_bundle
def obj_create(self, bundle, **kwargs):
"""
Creates a new object based on the provided data.
This needs to be implemented at the user level.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
def obj_update(self, bundle, **kwargs):
"""
Updates an existing object (or creates a new object) based on the
provided data.
This needs to be implemented at the user level.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
def obj_delete_list(self, bundle, **kwargs):
"""
Deletes an entire list of objects.
This needs to be implemented at the user level.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
def obj_delete_list_for_update(self, bundle, **kwargs):
"""
Deletes an entire list of objects, specific to PUT list.
This needs to be implemented at the user level.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
def obj_delete(self, bundle, **kwargs):
"""
Deletes a single object.
This needs to be implemented at the user level.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
def create_response(self, request, data, response_class=HttpResponse, **response_kwargs):
"""
Extracts the common "which-format/serialize/return-response" cycle.
Mostly a useful shortcut/hook.
"""
desired_format = self.determine_format(request)
serialized = self.serialize(request, data, desired_format)
return response_class(content=serialized, content_type=build_content_type(desired_format), **response_kwargs)
def error_response(self, request, errors, response_class=None):
"""
Extracts the common "which-format/serialize/return-error-response"
cycle.
Should be used as much as possible to return errors.
"""
if response_class is None:
response_class = http.HttpBadRequest
desired_format = None
if request:
if request.GET.get('callback', None) is None:
try:
desired_format = self.determine_format(request)
except BadRequest:
pass # Fall through to default handler below
else:
# JSONP can cause extra breakage.
desired_format = 'application/json'
if not desired_format:
desired_format = self._meta.default_format
try:
serialized = self.serialize(request, errors, desired_format)
except BadRequest as e:
error = "Additional errors occurred, but serialization of those errors failed."
if settings.DEBUG:
error += " %s" % e
return response_class(content=error, content_type='text/plain')
return response_class(content=serialized, content_type=build_content_type(desired_format))
def is_valid(self, bundle):
"""
Handles checking if the data provided by the user is valid.
Mostly a hook, this uses class assigned to ``validation`` from
``Resource._meta``.
If validation fails, an error is raised with the error messages
serialized inside it.
"""
errors = self._meta.validation.is_valid(bundle, bundle.request)
if errors:
bundle.errors[self._meta.resource_name] = errors
return False
return True
def rollback(self, bundles):
"""
Given the list of bundles, delete all objects pertaining to those
bundles.
This needs to be implemented at the user level. No exceptions should
be raised if possible.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
# Views.
def get_list(self, request, **kwargs):
"""
Returns a serialized list of resources.
Calls ``obj_get_list`` to provide the data, then handles that result
set and serializes it.
Should return a HttpResponse (200 OK).
"""
# TODO: Uncached for now. Invalidation that works for everyone may be
# impossible.
base_bundle = self.build_bundle(request=request)
objects = self.obj_get_list(bundle=base_bundle, **self.remove_api_resource_names(kwargs))
sorted_objects = self.apply_sorting(objects, options=request.GET)
paginator = self._meta.paginator_class(request.GET, sorted_objects, resource_uri=self.get_resource_uri(), limit=self._meta.limit, max_limit=self._meta.max_limit, collection_name=self._meta.collection_name)
to_be_serialized = paginator.page()
# Dehydrate the bundles in preparation for serialization.
bundles = []
for obj in to_be_serialized[self._meta.collection_name]:
bundle = self.build_bundle(obj=obj, request=request)
bundles.append(self.full_dehydrate(bundle, for_list=True))
to_be_serialized[self._meta.collection_name] = bundles
to_be_serialized = self.alter_list_data_to_serialize(request, to_be_serialized)
return self.create_response(request, to_be_serialized)
def get_detail(self, request, **kwargs):
"""
Returns a single serialized resource.
Calls ``cached_obj_get/obj_get`` to provide the data, then handles that result
set and serializes it.
Should return a HttpResponse (200 OK).
"""
basic_bundle = self.build_bundle(request=request)
try:
obj = self.cached_obj_get(bundle=basic_bundle, **self.remove_api_resource_names(kwargs))
except ObjectDoesNotExist:
return http.HttpNotFound()
except MultipleObjectsReturned:
return http.HttpMultipleChoices("More than one resource is found at this URI.")
bundle = self.build_bundle(obj=obj, request=request)
bundle = self.full_dehydrate(bundle)
bundle = self.alter_detail_data_to_serialize(request, bundle)
return self.create_response(request, bundle)
def post_list(self, request, **kwargs):
"""
Creates a new resource/object with the provided data.
Calls ``obj_create`` with the provided data and returns a response
with the new resource's location.
If a new resource is created, return ``HttpCreated`` (201 Created).
If ``Meta.always_return_data = True``, there will be a populated body
of serialized data.
"""
deserialized = self.deserialize(request, request.body, format=request.META.get('CONTENT_TYPE', 'application/json'))
deserialized = self.alter_deserialized_detail_data(request, deserialized)
bundle = self.build_bundle(data=dict_strip_unicode_keys(deserialized), request=request)
updated_bundle = self.obj_create(bundle, **self.remove_api_resource_names(kwargs))
location = self.get_resource_uri(updated_bundle)
if not self._meta.always_return_data:
return http.HttpCreated(location=location)
else:
updated_bundle = self.full_dehydrate(updated_bundle)
updated_bundle = self.alter_detail_data_to_serialize(request, updated_bundle)
return self.create_response(request, updated_bundle, response_class=http.HttpCreated, location=location)
def post_detail(self, request, **kwargs):
"""
Creates a new subcollection of the resource under a resource.
This is not implemented by default because most people's data models
aren't self-referential.
If a new resource is created, return ``HttpCreated`` (201 Created).
"""
return http.HttpNotImplemented()
def put_list(self, request, **kwargs):
"""
Replaces a collection of resources with another collection.
Calls ``delete_list`` to clear out the collection then ``obj_create``
with the provided the data to create the new collection.
Return ``HttpNoContent`` (204 No Content) if
``Meta.always_return_data = False`` (default).
Return ``HttpAccepted`` (200 OK) if
``Meta.always_return_data = True``.
"""
deserialized = self.deserialize(request, request.body, format=request.META.get('CONTENT_TYPE', 'application/json'))
deserialized = self.alter_deserialized_list_data(request, deserialized)
if not self._meta.collection_name in deserialized:
raise BadRequest("Invalid data sent.")
basic_bundle = self.build_bundle(request=request)
self.obj_delete_list_for_update(bundle=basic_bundle, **self.remove_api_resource_names(kwargs))
bundles_seen = []
for object_data in deserialized[self._meta.collection_name]:
bundle = self.build_bundle(data=dict_strip_unicode_keys(object_data), request=request)
# Attempt to be transactional, deleting any previously created
# objects if validation fails.
try:
self.obj_create(bundle=bundle, **self.remove_api_resource_names(kwargs))
bundles_seen.append(bundle)
except ImmediateHttpResponse:
self.rollback(bundles_seen)
raise
if not self._meta.always_return_data:
return http.HttpNoContent()
else:
to_be_serialized = {}
to_be_serialized[self._meta.collection_name] = [self.full_dehydrate(bundle, for_list=True) for bundle in bundles_seen]
to_be_serialized = self.alter_list_data_to_serialize(request, to_be_serialized)
return self.create_response(request, to_be_serialized)
def put_detail(self, request, **kwargs):
"""
Either updates an existing resource or creates a new one with the
provided data.
Calls ``obj_update`` with the provided data first, but falls back to
``obj_create`` if the object does not already exist.
If a new resource is created, return ``HttpCreated`` (201 Created).
If ``Meta.always_return_data = True``, there will be a populated body
of serialized data.
If an existing resource is modified and
``Meta.always_return_data = False`` (default), return ``HttpNoContent``
(204 No Content).
If an existing resource is modified and
``Meta.always_return_data = True``, return ``HttpAccepted`` (200
OK).
"""
deserialized = self.deserialize(request, request.body, format=request.META.get('CONTENT_TYPE', 'application/json'))
deserialized = self.alter_deserialized_detail_data(request, deserialized)
bundle = self.build_bundle(data=dict_strip_unicode_keys(deserialized), request=request)
try:
updated_bundle = self.obj_update(bundle=bundle, **self.remove_api_resource_names(kwargs))
if not self._meta.always_return_data:
return http.HttpNoContent()
else:
updated_bundle = self.full_dehydrate(updated_bundle)
updated_bundle = self.alter_detail_data_to_serialize(request, updated_bundle)
return self.create_response(request, updated_bundle)
except (NotFound, MultipleObjectsReturned):
updated_bundle = self.obj_create(bundle=bundle, **self.remove_api_resource_names(kwargs))
location = self.get_resource_uri(updated_bundle)
if not self._meta.always_return_data:
return http.HttpCreated(location=location)
else:
updated_bundle = self.full_dehydrate(updated_bundle)
updated_bundle = self.alter_detail_data_to_serialize(request, updated_bundle)
return self.create_response(request, updated_bundle, response_class=http.HttpCreated, location=location)
def delete_list(self, request, **kwargs):
"""
Destroys a collection of resources/objects.
Calls ``obj_delete_list``.
If the resources are deleted, return ``HttpNoContent`` (204 No Content).
"""
bundle = self.build_bundle(request=request)
self.obj_delete_list(bundle=bundle, request=request, **self.remove_api_resource_names(kwargs))
return http.HttpNoContent()
def delete_detail(self, request, **kwargs):
"""
Destroys a single resource/object.
Calls ``obj_delete``.
If the resource is deleted, return ``HttpNoContent`` (204 No Content).
If the resource did not exist, return ``Http404`` (404 Not Found).
"""
# Manually construct the bundle here, since we don't want to try to
# delete an empty instance.
bundle = Bundle(request=request)
try:
self.obj_delete(bundle=bundle, **self.remove_api_resource_names(kwargs))
return http.HttpNoContent()
except NotFound:
return http.HttpNotFound()
def patch_list(self, request, **kwargs):
"""
Updates a collection in-place.
The exact behavior of ``PATCH`` to a list resource is still the matter of
some debate in REST circles, and the ``PATCH`` RFC isn't standard. So the
behavior this method implements (described below) is something of a
stab in the dark. It's mostly cribbed from GData, with a smattering
of ActiveResource-isms and maybe even an original idea or two.
The ``PATCH`` format is one that's similar to the response returned from
a ``GET`` on a list resource::
{
"objects": [{object}, {object}, ...],
"deleted_objects": ["URI", "URI", "URI", ...],
}
For each object in ``objects``:
* If the dict does not have a ``resource_uri`` key then the item is
considered "new" and is handled like a ``POST`` to the resource list.
* If the dict has a ``resource_uri`` key and the ``resource_uri`` refers
to an existing resource then the item is a update; it's treated
like a ``PATCH`` to the corresponding resource detail.
* If the dict has a ``resource_uri`` but the resource *doesn't* exist,
then this is considered to be a create-via-``PUT``.
Each entry in ``deleted_objects`` referes to a resource URI of an existing
resource to be deleted; each is handled like a ``DELETE`` to the relevent
resource.
In any case:
* If there's a resource URI it *must* refer to a resource of this
type. It's an error to include a URI of a different resource.
* ``PATCH`` is all or nothing. If a single sub-operation fails, the
entire request will fail and all resources will be rolled back.
* For ``PATCH`` to work, you **must** have ``put`` in your
:ref:`detail-allowed-methods` setting.
* To delete objects via ``deleted_objects`` in a ``PATCH`` request you
**must** have ``delete`` in your :ref:`detail-allowed-methods`
setting.
Substitute appropriate names for ``objects`` and
``deleted_objects`` if ``Meta.collection_name`` is set to something
other than ``objects`` (default).
"""
request = convert_post_to_patch(request)
deserialized = self.deserialize(request, request.body, format=request.META.get('CONTENT_TYPE', 'application/json'))
collection_name = self._meta.collection_name
deleted_collection_name = 'deleted_%s' % collection_name
if collection_name not in deserialized:
raise BadRequest("Invalid data sent: missing '%s'" % collection_name)
if len(deserialized[collection_name]) and 'put' not in self._meta.detail_allowed_methods:
raise ImmediateHttpResponse(response=http.HttpMethodNotAllowed())
bundles_seen = []
for data in deserialized[collection_name]:
# If there's a resource_uri then this is either an
# update-in-place or a create-via-PUT.
if "resource_uri" in data:
uri = data.pop('resource_uri')
try:
obj = self.get_via_uri(uri, request=request)
# The object does exist, so this is an update-in-place.
bundle = self.build_bundle(obj=obj, request=request)
bundle = self.full_dehydrate(bundle, for_list=True)
bundle = self.alter_detail_data_to_serialize(request, bundle)
self.update_in_place(request, bundle, data)
except (ObjectDoesNotExist, MultipleObjectsReturned):
# The object referenced by resource_uri doesn't exist,
# so this is a create-by-PUT equivalent.
data = self.alter_deserialized_detail_data(request, data)
bundle = self.build_bundle(data=dict_strip_unicode_keys(data), request=request)
self.obj_create(bundle=bundle)
else:
# There's no resource URI, so this is a create call just
# like a POST to the list resource.
data = self.alter_deserialized_detail_data(request, data)
bundle = self.build_bundle(data=dict_strip_unicode_keys(data), request=request)
self.obj_create(bundle=bundle)
bundles_seen.append(bundle)
deleted_collection = deserialized.get(deleted_collection_name, [])
if deleted_collection:
if 'delete' not in self._meta.detail_allowed_methods:
raise ImmediateHttpResponse(response=http.HttpMethodNotAllowed())
for uri in deleted_collection:
obj = self.get_via_uri(uri, request=request)
bundle = self.build_bundle(obj=obj, request=request)
self.obj_delete(bundle=bundle)
if not self._meta.always_return_data:
return http.HttpAccepted()
else:
to_be_serialized = {}
to_be_serialized['objects'] = [self.full_dehydrate(bundle, for_list=True) for bundle in bundles_seen]
to_be_serialized = self.alter_list_data_to_serialize(request, to_be_serialized)
return self.create_response(request, to_be_serialized, response_class=http.HttpAccepted)
def patch_detail(self, request, **kwargs):
"""
Updates a resource in-place.
Calls ``obj_update``.
If the resource is updated, return ``HttpAccepted`` (202 Accepted).
If the resource did not exist, return ``HttpNotFound`` (404 Not Found).
"""
request = convert_post_to_patch(request)
basic_bundle = self.build_bundle(request=request)
# We want to be able to validate the update, but we can't just pass
# the partial data into the validator since all data needs to be
# present. Instead, we basically simulate a PUT by pulling out the
# original data and updating it in-place.
# So first pull out the original object. This is essentially
# ``get_detail``.
try:
obj = self.cached_obj_get(bundle=basic_bundle, **self.remove_api_resource_names(kwargs))
except ObjectDoesNotExist:
return http.HttpNotFound()
except MultipleObjectsReturned:
return http.HttpMultipleChoices("More than one resource is found at this URI.")
bundle = self.build_bundle(obj=obj, request=request)
bundle = self.full_dehydrate(bundle)
bundle = self.alter_detail_data_to_serialize(request, bundle)
# Now update the bundle in-place.
deserialized = self.deserialize(request, request.body, format=request.META.get('CONTENT_TYPE', 'application/json'))
self.update_in_place(request, bundle, deserialized)
if not self._meta.always_return_data:
return http.HttpAccepted()
else:
bundle = self.full_dehydrate(bundle)
bundle = self.alter_detail_data_to_serialize(request, bundle)
return self.create_response(request, bundle, response_class=http.HttpAccepted)
def update_in_place(self, request, original_bundle, new_data):
"""
Update the object in original_bundle in-place using new_data.
"""
original_bundle.data.update(**dict_strip_unicode_keys(new_data))
# Now we've got a bundle with the new data sitting in it and we're
# we're basically in the same spot as a PUT request. SO the rest of this
# function is cribbed from put_detail.
self.alter_deserialized_detail_data(request, original_bundle.data)
kwargs = {
self._meta.detail_uri_name: self.get_bundle_detail_data(original_bundle),
'request': request,
}
return self.obj_update(bundle=original_bundle, **kwargs)
def get_schema(self, request, **kwargs):
"""
Returns a serialized form of the schema of the resource.
Calls ``build_schema`` to generate the data. This method only responds
to HTTP GET.
Should return a HttpResponse (200 OK).
"""
self.method_check(request, allowed=['get'])
self.is_authenticated(request)
self.throttle_check(request)
self.log_throttled_access(request)
bundle = self.build_bundle(request=request)
self.authorized_read_detail(self.get_object_list(bundle.request), bundle)
return self.create_response(request, self.build_schema())
def get_multiple(self, request, **kwargs):
"""
Returns a serialized list of resources based on the identifiers
from the URL.
Calls ``obj_get`` to fetch only the objects requested. This method
only responds to HTTP GET.
Should return a HttpResponse (200 OK).
"""
self.method_check(request, allowed=['get'])
self.is_authenticated(request)
self.throttle_check(request)
# Rip apart the list then iterate.
kwarg_name = '%s_list' % self._meta.detail_uri_name
obj_identifiers = kwargs.get(kwarg_name, '').split(';')
objects = []
not_found = []
base_bundle = self.build_bundle(request=request)
for identifier in obj_identifiers:
try:
obj = self.obj_get(bundle=base_bundle, **{self._meta.detail_uri_name: identifier})
bundle = self.build_bundle(obj=obj, request=request)
bundle = self.full_dehydrate(bundle, for_list=True)
objects.append(bundle)
except (ObjectDoesNotExist, Unauthorized):
not_found.append(identifier)
object_list = {
self._meta.collection_name: objects,
}
if len(not_found):
object_list['not_found'] = not_found
self.log_throttled_access(request)
return self.create_response(request, object_list)
class ModelDeclarativeMetaclass(DeclarativeMetaclass):
def __new__(cls, name, bases, attrs):
meta = attrs.get('Meta')
if meta and hasattr(meta, 'queryset'):
setattr(meta, 'object_class', meta.queryset.model)
new_class = super(ModelDeclarativeMetaclass, cls).__new__(cls, name, bases, attrs)
include_fields = getattr(new_class._meta, 'fields', [])
excludes = getattr(new_class._meta, 'excludes', [])
field_names = list(new_class.base_fields.keys())
for field_name in field_names:
if field_name == 'resource_uri':
continue
if field_name in new_class.declared_fields:
continue
if len(include_fields) and not field_name in include_fields:
del(new_class.base_fields[field_name])
if len(excludes) and field_name in excludes:
del(new_class.base_fields[field_name])
# Add in the new fields.
new_class.base_fields.update(new_class.get_fields(include_fields, excludes))
if getattr(new_class._meta, 'include_absolute_url', True):
if not 'absolute_url' in new_class.base_fields:
new_class.base_fields['absolute_url'] = fields.CharField(attribute='get_absolute_url', readonly=True)
elif 'absolute_url' in new_class.base_fields and not 'absolute_url' in attrs:
del(new_class.base_fields['absolute_url'])
return new_class
class BaseModelResource(Resource):
"""
A subclass of ``Resource`` designed to work with Django's ``Models``.
This class will introspect a given ``Model`` and build a field list based
on the fields found on the model (excluding relational fields).
Given that it is aware of Django's ORM, it also handles the CRUD data
operations of the resource.
"""
@classmethod
def should_skip_field(cls, field):
"""
Given a Django model field, return if it should be included in the
contributed ApiFields.
"""
# Ignore certain fields (related fields).
if getattr(field, 'rel'):
return True
return False
@classmethod
def api_field_from_django_field(cls, f, default=fields.CharField):
"""
Returns the field type that would likely be associated with each
Django type.
"""
result = default
internal_type = f.get_internal_type()
if internal_type in ('DateField', 'DateTimeField'):
result = fields.DateTimeField
elif internal_type in ('BooleanField', 'NullBooleanField'):
result = fields.BooleanField
elif internal_type in ('FloatField',):
result = fields.FloatField
elif internal_type in ('DecimalField',):
result = fields.DecimalField
elif internal_type in ('IntegerField', 'PositiveIntegerField', 'PositiveSmallIntegerField', 'SmallIntegerField', 'AutoField'):
result = fields.IntegerField
elif internal_type in ('FileField', 'ImageField'):
result = fields.FileField
elif internal_type == 'TimeField':
result = fields.TimeField
# TODO: Perhaps enable these via introspection. The reason they're not enabled
# by default is the very different ``__init__`` they have over
# the other fields.
# elif internal_type == 'ForeignKey':
# result = ForeignKey
# elif internal_type == 'ManyToManyField':
# result = ManyToManyField
return result
@classmethod
def get_fields(cls, fields=None, excludes=None):
"""
Given any explicit fields to include and fields to exclude, add
additional fields based on the associated model.
"""
final_fields = {}
fields = fields or []
excludes = excludes or []
if not cls._meta.object_class:
return final_fields
for f in cls._meta.object_class._meta.fields:
# If the field name is already present, skip
if f.name in cls.base_fields:
continue
# If field is not present in explicit field listing, skip
if fields and f.name not in fields:
continue
# If field is in exclude list, skip
if excludes and f.name in excludes:
continue
if cls.should_skip_field(f):
continue
api_field_class = cls.api_field_from_django_field(f)
kwargs = {
'attribute': f.name,
'help_text': f.help_text,
}
if f.null is True:
kwargs['null'] = True
kwargs['unique'] = f.unique
if not f.null and f.blank is True:
kwargs['default'] = ''
kwargs['blank'] = True
if f.get_internal_type() == 'TextField':
kwargs['default'] = ''
if f.has_default():
kwargs['default'] = f.default
if getattr(f, 'auto_now', False):
kwargs['default'] = f.auto_now
if getattr(f, 'auto_now_add', False):
kwargs['default'] = f.auto_now_add
final_fields[f.name] = api_field_class(**kwargs)
final_fields[f.name].instance_name = f.name
return final_fields
def check_filtering(self, field_name, filter_type='exact', filter_bits=None):
"""
Given a field name, a optional filter type and an optional list of
additional relations, determine if a field can be filtered on.
If a filter does not meet the needed conditions, it should raise an
``InvalidFilterError``.
If the filter meets the conditions, a list of attribute names (not
field names) will be returned.
"""
if filter_bits is None:
filter_bits = []
if not field_name in self._meta.filtering:
raise InvalidFilterError("The '%s' field does not allow filtering." % field_name)
# Check to see if it's an allowed lookup type.
if not self._meta.filtering[field_name] in (ALL, ALL_WITH_RELATIONS):
# Must be an explicit whitelist.
if not filter_type in self._meta.filtering[field_name]:
raise InvalidFilterError("'%s' is not an allowed filter on the '%s' field." % (filter_type, field_name))
if self.fields[field_name].attribute is None:
raise InvalidFilterError("The '%s' field has no 'attribute' for searching with." % field_name)
# Check to see if it's a relational lookup and if that's allowed.
if len(filter_bits):
if not getattr(self.fields[field_name], 'is_related', False):
raise InvalidFilterError("The '%s' field does not support relations." % field_name)
if not self._meta.filtering[field_name] == ALL_WITH_RELATIONS:
raise InvalidFilterError("Lookups are not allowed more than one level deep on the '%s' field." % field_name)
# Recursively descend through the remaining lookups in the filter,
# if any. We should ensure that all along the way, we're allowed
# to filter on that field by the related resource.
related_resource = self.fields[field_name].get_related_resource(None)
return [self.fields[field_name].attribute] + related_resource.check_filtering(filter_bits[0], filter_type, filter_bits[1:])
return [self.fields[field_name].attribute]
def filter_value_to_python(self, value, field_name, filters, filter_expr,
filter_type):
"""
Turn the string ``value`` into a python object.
"""
# Simple values
if value in ['true', 'True', True]:
value = True
elif value in ['false', 'False', False]:
value = False
elif value in ('nil', 'none', 'None', None):
value = None
# Split on ',' if not empty string and either an in or range filter.
if filter_type in ('in', 'range') and len(value):
if hasattr(filters, 'getlist'):
value = []
for part in filters.getlist(filter_expr):
value.extend(part.split(','))
else:
value = value.split(',')
return value
def build_filters(self, filters=None):
"""
Given a dictionary of filters, create the necessary ORM-level filters.
Keys should be resource fields, **NOT** model fields.
Valid values are either a list of Django filter types (i.e.
``['startswith', 'exact', 'lte']``), the ``ALL`` constant or the
``ALL_WITH_RELATIONS`` constant.
"""
# At the declarative level:
# filtering = {
# 'resource_field_name': ['exact', 'startswith', 'endswith', 'contains'],
# 'resource_field_name_2': ['exact', 'gt', 'gte', 'lt', 'lte', 'range'],
# 'resource_field_name_3': ALL,
# 'resource_field_name_4': ALL_WITH_RELATIONS,
# ...
# }
# Accepts the filters as a dict. None by default, meaning no filters.
if filters is None:
filters = {}
qs_filters = {}
if getattr(self._meta, 'queryset', None) is not None:
# Get the possible query terms from the current QuerySet.
query_terms = self._meta.queryset.query.query_terms
else:
query_terms = QUERY_TERMS
for filter_expr, value in filters.items():
filter_bits = filter_expr.split(LOOKUP_SEP)
field_name = filter_bits.pop(0)
filter_type = 'exact'
if not field_name in self.fields:
# It's not a field we know about. Move along citizen.
continue
if len(filter_bits) and filter_bits[-1] in query_terms:
filter_type = filter_bits.pop()
lookup_bits = self.check_filtering(field_name, filter_type, filter_bits)
value = self.filter_value_to_python(value, field_name, filters, filter_expr, filter_type)
db_field_name = LOOKUP_SEP.join(lookup_bits)
qs_filter = "%s%s%s" % (db_field_name, LOOKUP_SEP, filter_type)
qs_filters[qs_filter] = value
return dict_strip_unicode_keys(qs_filters)
def apply_sorting(self, obj_list, options=None):
"""
Given a dictionary of options, apply some ORM-level sorting to the
provided ``QuerySet``.
Looks for the ``order_by`` key and handles either ascending (just the
field name) or descending (the field name with a ``-`` in front).
The field name should be the resource field, **NOT** model field.
"""
if options is None:
options = {}
parameter_name = 'order_by'
if not 'order_by' in options:
if not 'sort_by' in options:
# Nothing to alter the order. Return what we've got.
return obj_list
else:
warnings.warn("'sort_by' is a deprecated parameter. Please use 'order_by' instead.")
parameter_name = 'sort_by'
order_by_args = []
if hasattr(options, 'getlist'):
order_bits = options.getlist(parameter_name)
else:
order_bits = options.get(parameter_name)
if not isinstance(order_bits, (list, tuple)):
order_bits = [order_bits]
for order_by in order_bits:
order_by_bits = order_by.split(LOOKUP_SEP)
field_name = order_by_bits[0]
order = ''
if order_by_bits[0].startswith('-'):
field_name = order_by_bits[0][1:]
order = '-'
if not field_name in self.fields:
# It's not a field we know about. Move along citizen.
raise InvalidSortError("No matching '%s' field for ordering on." % field_name)
if not field_name in self._meta.ordering:
raise InvalidSortError("The '%s' field does not allow ordering." % field_name)
if self.fields[field_name].attribute is None:
raise InvalidSortError("The '%s' field has no 'attribute' for ordering with." % field_name)
order_by_args.append("%s%s" % (order, LOOKUP_SEP.join([self.fields[field_name].attribute] + order_by_bits[1:])))
return obj_list.order_by(*order_by_args)
def apply_filters(self, request, applicable_filters):
"""
An ORM-specific implementation of ``apply_filters``.
The default simply applies the ``applicable_filters`` as ``**kwargs``,
but should make it possible to do more advanced things.
"""
return self.get_object_list(request).filter(**applicable_filters)
def get_object_list(self, request):
"""
An ORM-specific implementation of ``get_object_list``.
Returns a queryset that may have been limited by other overrides.
"""
return self._meta.queryset._clone()
def obj_get_list(self, bundle, **kwargs):
"""
A ORM-specific implementation of ``obj_get_list``.
Takes an optional ``request`` object, whose ``GET`` dictionary can be
used to narrow the query.
"""
filters = {}
if hasattr(bundle.request, 'GET'):
# Grab a mutable copy.
filters = bundle.request.GET.copy()
# Update with the provided kwargs.
filters.update(kwargs)
applicable_filters = self.build_filters(filters=filters)
try:
objects = self.apply_filters(bundle.request, applicable_filters)
return self.authorized_read_list(objects, bundle)
except ValueError:
raise BadRequest("Invalid resource lookup data provided (mismatched type).")
except TypeError as e:
raise BadRequest("Invalid resource lookup data provided (%s)." % e)
def obj_get(self, bundle, **kwargs):
"""
A ORM-specific implementation of ``obj_get``.
Takes optional ``kwargs``, which are used to narrow the query to find
the instance.
"""
try:
object_list = self.get_object_list(bundle.request).filter(**kwargs)
stringified_kwargs = ', '.join(["%s=%s" % (k, v) for k, v in kwargs.items()])
if len(object_list) <= 0:
raise self._meta.object_class.DoesNotExist("Couldn't find an instance of '%s' which matched '%s'." % (self._meta.object_class.__name__, stringified_kwargs))
elif len(object_list) > 1:
raise MultipleObjectsReturned("More than '%s' matched '%s'." % (self._meta.object_class.__name__, stringified_kwargs))
bundle.obj = object_list[0]
self.authorized_read_detail(object_list, bundle)
return bundle.obj
except ValueError:
raise NotFound("Invalid resource lookup data provided (mismatched type).")
def obj_create(self, bundle, **kwargs):
"""
A ORM-specific implementation of ``obj_create``.
"""
bundle.obj = self._meta.object_class()
for key, value in kwargs.items():
setattr(bundle.obj, key, value)
bundle = self.full_hydrate(bundle)
return self.save(bundle)
def lookup_kwargs_with_identifiers(self, bundle, kwargs):
"""
Kwargs here represent uri identifiers Ex: /repos/<user_id>/<repo_name>/
We need to turn those identifiers into Python objects for generating
lookup parameters that can find them in the DB
"""
lookup_kwargs = {}
bundle.obj = self.get_object_list(bundle.request).model()
# Override data values, we rely on uri identifiers
bundle.data.update(kwargs)
# We're going to manually hydrate, as opposed to calling
# ``full_hydrate``, to ensure we don't try to flesh out related
# resources & keep things speedy.
bundle = self.hydrate(bundle)
for identifier in kwargs:
if identifier == self._meta.detail_uri_name:
lookup_kwargs[identifier] = kwargs[identifier]
continue
field_object = self.fields[identifier]
# Skip readonly or related fields.
if field_object.readonly is True or getattr(field_object, 'is_related', False):
continue
# Check for an optional method to do further hydration.
method = getattr(self, "hydrate_%s" % identifier, None)
if method:
bundle = method(bundle)
if field_object.attribute:
value = field_object.hydrate(bundle)
lookup_kwargs[identifier] = value
return lookup_kwargs
def obj_update(self, bundle, skip_errors=False, **kwargs):
"""
A ORM-specific implementation of ``obj_update``.
"""
if not bundle.obj or not self.get_bundle_detail_data(bundle):
try:
lookup_kwargs = self.lookup_kwargs_with_identifiers(bundle, kwargs)
except:
# if there is trouble hydrating the data, fall back to just
# using kwargs by itself (usually it only contains a "pk" key
# and this will work fine.
lookup_kwargs = kwargs
try:
bundle.obj = self.obj_get(bundle=bundle, **lookup_kwargs)
except ObjectDoesNotExist:
raise NotFound("A model instance matching the provided arguments could not be found.")
bundle = self.full_hydrate(bundle)
return self.save(bundle, skip_errors=skip_errors)
def obj_delete_list(self, bundle, **kwargs):
"""
A ORM-specific implementation of ``obj_delete_list``.
"""
objects_to_delete = self.obj_get_list(bundle=bundle, **kwargs)
deletable_objects = self.authorized_delete_list(objects_to_delete, bundle)
if hasattr(deletable_objects, 'delete'):
# It's likely a ``QuerySet``. Call ``.delete()`` for efficiency.
deletable_objects.delete()
else:
for authed_obj in deletable_objects:
authed_obj.delete()
def obj_delete_list_for_update(self, bundle, **kwargs):
"""
A ORM-specific implementation of ``obj_delete_list_for_update``.
"""
objects_to_delete = self.obj_get_list(bundle=bundle, **kwargs)
deletable_objects = self.authorized_update_list(objects_to_delete, bundle)
if hasattr(deletable_objects, 'delete'):
# It's likely a ``QuerySet``. Call ``.delete()`` for efficiency.
deletable_objects.delete()
else:
for authed_obj in deletable_objects:
authed_obj.delete()
def obj_delete(self, bundle, **kwargs):
"""
A ORM-specific implementation of ``obj_delete``.
Takes optional ``kwargs``, which are used to narrow the query to find
the instance.
"""
if not hasattr(bundle.obj, 'delete'):
try:
bundle.obj = self.obj_get(bundle=bundle, **kwargs)
except ObjectDoesNotExist:
raise NotFound("A model instance matching the provided arguments could not be found.")
self.authorized_delete_detail(self.get_object_list(bundle.request), bundle)
bundle.obj.delete()
@transaction.commit_on_success()
def patch_list(self, request, **kwargs):
"""
An ORM-specific implementation of ``patch_list``.
Necessary because PATCH should be atomic (all-success or all-fail)
and the only way to do this neatly is at the database level.
"""
return super(BaseModelResource, self).patch_list(request, **kwargs)
def rollback(self, bundles):
"""
A ORM-specific implementation of ``rollback``.
Given the list of bundles, delete all models pertaining to those
bundles.
"""
for bundle in bundles:
if bundle.obj and self.get_bundle_detail_data(bundle):
bundle.obj.delete()
def create_identifier(self, obj):
return u"%s.%s.%s" % (obj._meta.app_label, obj._meta.module_name, obj.pk)
def save(self, bundle, skip_errors=False):
self.is_valid(bundle)
if bundle.errors and not skip_errors:
raise ImmediateHttpResponse(response=self.error_response(bundle.request, bundle.errors))
# Check if they're authorized.
if bundle.obj.pk:
self.authorized_update_detail(self.get_object_list(bundle.request), bundle)
else:
self.authorized_create_detail(self.get_object_list(bundle.request), bundle)
# Save FKs just in case.
self.save_related(bundle)
# Save the main object.
bundle.obj.save()
bundle.objects_saved.add(self.create_identifier(bundle.obj))
# Now pick up the M2M bits.
m2m_bundle = self.hydrate_m2m(bundle)
self.save_m2m(m2m_bundle)
return bundle
def save_related(self, bundle):
"""
Handles the saving of related non-M2M data.
Calling assigning ``child.parent = parent`` & then calling
``Child.save`` isn't good enough to make sure the ``parent``
is saved.
To get around this, we go through all our related fields &
call ``save`` on them if they have related, non-M2M data.
M2M data is handled by the ``ModelResource.save_m2m`` method.
"""
for field_name, field_object in self.fields.items():
if not getattr(field_object, 'is_related', False):
continue
if getattr(field_object, 'is_m2m', False):
continue
if not field_object.attribute:
continue
if field_object.readonly:
continue
if field_object.blank and not field_name in bundle.data:
continue
# Get the object.
try:
related_obj = getattr(bundle.obj, field_object.attribute)
except ObjectDoesNotExist:
related_obj = bundle.related_objects_to_save.get(field_object.attribute, None)
# Because sometimes it's ``None`` & that's OK.
if related_obj:
if field_object.related_name:
if not self.get_bundle_detail_data(bundle):
bundle.obj.save()
setattr(related_obj, field_object.related_name, bundle.obj)
related_resource = field_object.get_related_resource(related_obj)
# Before we build the bundle & try saving it, let's make sure we
# haven't already saved it.
obj_id = self.create_identifier(related_obj)
if obj_id in bundle.objects_saved:
# It's already been saved. We're done here.
continue
if bundle.data.get(field_name) and hasattr(bundle.data[field_name], 'keys'):
# Only build & save if there's data, not just a URI.
related_bundle = related_resource.build_bundle(
obj=related_obj,
data=bundle.data.get(field_name),
request=bundle.request,
objects_saved=bundle.objects_saved
)
related_resource.save(related_bundle)
setattr(bundle.obj, field_object.attribute, related_obj)
def save_m2m(self, bundle):
"""
Handles the saving of related M2M data.
Due to the way Django works, the M2M data must be handled after the
main instance, which is why this isn't a part of the main ``save`` bits.
Currently slightly inefficient in that it will clear out the whole
relation and recreate the related data as needed.
"""
for field_name, field_object in self.fields.items():
if not getattr(field_object, 'is_m2m', False):
continue
if not field_object.attribute:
continue
if field_object.readonly:
continue
# Get the manager.
related_mngr = None
if isinstance(field_object.attribute, six.string_types):
related_mngr = getattr(bundle.obj, field_object.attribute)
elif callable(field_object.attribute):
related_mngr = field_object.attribute(bundle)
if not related_mngr:
continue
if hasattr(related_mngr, 'clear'):
# FIXME: Dupe the original bundle, copy in the new object &
# check the perms on that (using the related resource)?
# Clear it out, just to be safe.
related_mngr.clear()
related_objs = []
for related_bundle in bundle.data[field_name]:
related_resource = field_object.get_related_resource(bundle.obj)
# Before we build the bundle & try saving it, let's make sure we
# haven't already saved it.
obj_id = self.create_identifier(related_bundle.obj)
if obj_id in bundle.objects_saved:
# It's already been saved. We're done here.
continue
# Only build & save if there's data, not just a URI.
updated_related_bundle = related_resource.build_bundle(
obj=related_bundle.obj,
data=related_bundle.data,
request=bundle.request,
objects_saved=bundle.objects_saved
)
#Only save related models if they're newly added.
if updated_related_bundle.obj._state.adding:
related_resource.save(updated_related_bundle)
related_objs.append(updated_related_bundle.obj)
related_mngr.add(*related_objs)
def detail_uri_kwargs(self, bundle_or_obj):
"""
Given a ``Bundle`` or an object (typically a ``Model`` instance),
it returns the extra kwargs needed to generate a detail URI.
By default, it uses the model's ``pk`` in order to create the URI.
"""
kwargs = {}
if isinstance(bundle_or_obj, Bundle):
kwargs[self._meta.detail_uri_name] = getattr(bundle_or_obj.obj, self._meta.detail_uri_name)
else:
kwargs[self._meta.detail_uri_name] = getattr(bundle_or_obj, self._meta.detail_uri_name)
return kwargs
class ModelResource(six.with_metaclass(ModelDeclarativeMetaclass, BaseModelResource)):
pass
class NamespacedModelResource(ModelResource):
"""
A ModelResource subclass that respects Django namespaces.
"""
def _build_reverse_url(self, name, args=None, kwargs=None):
namespaced = "%s:%s" % (self._meta.urlconf_namespace, name)
return reverse(namespaced, args=args, kwargs=kwargs)
# Based off of ``piston.utils.coerce_put_post``. Similarly BSD-licensed.
# And no, the irony is not lost on me.
def convert_post_to_VERB(request, verb):
"""
Force Django to process the VERB.
"""
if request.method == verb:
if hasattr(request, '_post'):
del(request._post)
del(request._files)
try:
request.method = "POST"
request._load_post_and_files()
request.method = verb
except AttributeError:
request.META['REQUEST_METHOD'] = 'POST'
request._load_post_and_files()
request.META['REQUEST_METHOD'] = verb
setattr(request, verb, request.POST)
return request
def convert_post_to_put(request):
return convert_post_to_VERB(request, verb='PUT')
def convert_post_to_patch(request):
return convert_post_to_VERB(request, verb='PATCH')