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resources.py
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resources.py
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import logging
import warnings
import django
from django.conf import settings
from django.conf.urls.defaults 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.db.models.sql.constants import QUERY_TERMS, LOOKUP_SEP
from django.http import HttpResponse, HttpResponseNotFound
from django.utils.cache import patch_cache_control
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
from tastypie.fields import *
from tastypie.http import *
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
try:
set
except NameError:
from sets import Set as set
# The ``copy`` module became function-friendly in Python 2.5 and
# ``copycompat`` was added in post 1.1.1 Django (r11901)..
try:
from django.utils.copycompat import deepcopy
except ImportError:
from copy import deepcopy
# 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
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']
list_allowed_methods = None
detail_allowed_methods = None
limit = getattr(settings, 'API_LIMIT_PER_PAGE', 20)
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
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'])
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
return object.__new__(type('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)]
for p in parents:
fields = getattr(p, 'base_fields', {})
for field_name, field_object in fields.items():
attrs['base_fields'][field_name] = deepcopy(field_object)
except NameError:
pass
for field_name, obj in attrs.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'] = 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(object):
"""
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.
"""
__metaclass__ = DeclarativeMetaclass
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)
if request.is_ajax():
# 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, ApiFieldError), e:
return HttpBadRequest(e.args[0])
except ValidationError, e:
return HttpBadRequest(', '.join(e.messages))
except Exception, 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
# 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 = HttpApplicationError
if isinstance(exception, (NotFound, ObjectDoesNotExist)):
response_class = HttpResponseNotFound
if settings.DEBUG:
data = {
"error_message": unicode(exception),
"traceback": the_trace,
}
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))
# When DEBUG is False, send an error message to the admins (unless it's
# a 404, in which case we check the setting).
if not isinstance(exception, (NotFound, ObjectDoesNotExist)):
log = logging.getLogger('django.request.tastypie')
log.error('Internal Server Error: %s' % request.path, exc_info=sys.exc_info(), extra={'status_code': 500, 'request':request})
if django.VERSION < (1, 3, 0) and getattr(settings, 'SEND_BROKEN_LINK_EMAILS', False):
from django.core.mail import mail_admins
subject = 'Error (%s IP): %s' % ((request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS and 'internal' or 'EXTERNAL'), request.path)
try:
request_repr = repr(request)
except:
request_repr = "Request repr() unavailable"
message = "%s\n\n%s" % (the_trace, request_repr)
mail_admins(subject, message, fail_silently=True)
# Prep the data going out.
data = {
"error_message": getattr(settings, 'TASTYPIE_CANNED_ERROR', "Sorry, this request could not be processed. Please try again later."),
}
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))
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.
"""
# Due to the way Django parses URLs, ``get_multiple`` won't work without
# a trailing slash.
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<pk_list>\w[\w/;-]*)/$" % self._meta.resource_name, self.wrap_view('get_multiple'), name="api_get_multiple"),
url(r"^(?P<resource_name>%s)/(?P<pk>\w[\w/-]*)%s$" % (self._meta.resource_name, trailing_slash()), self.wrap_view('dispatch_detail'), name="api_dispatch_detail"),
]
def override_urls(self):
"""
A hook for adding your own URLs or overriding 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.override_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)
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=HttpNotImplemented())
self.is_authenticated(request)
self.is_authorized(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 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()
if request_method == "options":
allows = ','.join(map(str.upper, allowed))
response = HttpResponse(allows)
response['Allow'] = allows
raise ImmediateHttpResponse(response=response)
if not request_method in allowed:
raise ImmediateHttpResponse(response=HttpMethodNotAllowed())
return request_method
def is_authorized(self, request, object=None):
"""
Handles checking of permissions to see if the user has authorization
to GET, POST, PUT, or DELETE this resource. If ``object`` is provided,
the authorization backend can apply additional row-level permissions
checking.
"""
auth_result = self._meta.authorization.is_authorized(request, object)
if isinstance(auth_result, HttpResponse):
raise ImmediateHttpResponse(response=auth_result)
if not auth_result is True:
raise ImmediateHttpResponse(response=HttpUnauthorized())
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=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=HttpForbidden())
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 build_bundle(self, obj=None, data=None, request=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:
obj = self._meta.object_class()
return Bundle(obj=obj, data=data, request=request)
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
# URL-related methods.
def get_resource_uri(self, bundle_or_obj):
"""
This needs to be implemented at the user level.
A ``return reverse("api_dispatch_detail", kwargs={'resource_name':
self.resource_name, 'pk': object.id})`` should be all that would
be needed.
``ModelResource`` includes a full working version specific to Django's
``Models``.
"""
raise NotImplementedError()
def get_resource_list_uri(self):
"""
Returns a URL specific to this resource's list endpoint.
"""
kwargs = {
'resource_name': self._meta.resource_name,
}
if self._meta.api_name is not None:
kwargs['api_name'] = self._meta.api_name
try:
return self._build_reverse_url("api_dispatch_list", kwargs=kwargs)
except NoReverseMatch:
return None
def get_via_uri(self, uri):
"""
This pulls apart the salient bits of the URI and populates the
resource via a ``obj_get``.
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:]
try:
view, args, kwargs = resolve(chomped_uri)
except Resolver404:
raise NotFound("The URL provided '%s' was not a link to a valid resource." % uri)
return self.obj_get(**self.remove_api_resource_names(kwargs))
# Data preparation.
def full_dehydrate(self, bundle):
"""
Given a bundle with an object instance, extract the information from it
to populate the resource.
"""
# Dehydrate each field.
for field_name, field_object in self.fields.items():
# 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)
# 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()
for field_name, field_object in self.fields.items():
if field_object.readonly is True:
continue
if field_object.attribute:
value = field_object.hydrate(bundle)
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:
setattr(bundle.obj, field_object.attribute, value.obj)
elif field_object.blank:
continue
elif field_object.null:
setattr(bundle.obj, field_object.attribute, value)
# Check for an optional method to do further hydration.
method = getattr(self, "hydrate_%s" % field_name, None)
if method:
bundle = method(bundle)
bundle = self.hydrate(bundle)
return bundle
def hydrate(self, bundle):
"""
A hook to allow a final manipulation of data once all fields/methods
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,
}
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] = {
'type': field_object.dehydrated_type,
'nullable': field_object.null,
'readonly': field_object.readonly,
'help_text': field_object.help_text,
}
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(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):
"""
Allows the ``Authorization`` class to further limit the object list.
Also a hook to customize per ``Resource``.
"""
if hasattr(self._meta.authorization, 'apply_limits'):
object_list = self._meta.authorization.apply_limits(request, object_list)
return 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, request=None, **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, request=None, **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(request=request, **kwargs)
self._meta.cache.set(cache_key, obj_list)
return obj_list
def obj_get(self, request=None, **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, request=None, **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)
bundle = self._meta.cache.get(cache_key)
if bundle is None:
bundle = self.obj_get(request=request, **kwargs)
self._meta.cache.set(cache_key, bundle)
return bundle
def obj_create(self, bundle, request=None, **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, request=None, **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, request=None, **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(self, request=None, **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 is_valid(self, bundle, request=None):
"""
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, request)
if len(errors):
if request:
desired_format = self.determine_format(request)
else:
desired_format = self._meta.default_format
serialized = self.serialize(request, errors, desired_format)
response = HttpBadRequest(content=serialized, content_type=build_content_type(desired_format))
raise ImmediateHttpResponse(response=response)
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.