django-rest-framework/djangorestframework/modelresource.py

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from django.forms import ModelForm
from django.db.models import Model
from django.db.models.query import QuerySet
from django.db.models.fields.related import RelatedField
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from djangorestframework.response import Response, ResponseException
from djangorestframework.resource import Resource
from djangorestframework.validators import ModelFormValidatorMixin
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from djangorestframework import status
import decimal
import inspect
import re
class ModelResource(Resource, ModelFormValidatorMixin):
"""A specialized type of Resource, for resources that map directly to a Django Model.
Useful things this provides:
0. Default input validation based on ModelForms.
1. Nice serialization of returned Models and QuerySets.
2. A default set of create/read/update/delete operations."""
# The model attribute refers to the Django Model which this Resource maps to.
# (The Model's class, rather than an instance of the Model)
model = None
# By default the set of returned fields will be the set of:
#
# 0. All the fields on the model, excluding 'id'.
# 1. All the properties on the model.
# 2. The absolute_url of the model, if a get_absolute_url method exists for the model.
#
# If you wish to override this behaviour,
# you should explicitly set the fields attribute on your class.
fields = None
# By default the form used with be a ModelForm for self.model
# If you wish to override this behaviour or provide a sub-classed ModelForm
# you should explicitly set the form attribute on your class.
form = None
# By default the set of input fields will be the same as the set of output fields
# If you wish to override this behaviour you should explicitly set the
# form_fields attribute on your class.
#form_fields = None
#def get_form(self, content=None):
# """Return a form that may be used in validation and/or rendering an html emitter"""
# if self.form:
# return super(self.__class__, self).get_form(content)
#
# elif self.model:
#
# class NewModelForm(ModelForm):
# class Meta:
# model = self.model
# fields = self.form_fields if self.form_fields else None
#
# if content and isinstance(content, Model):
# return NewModelForm(instance=content)
# elif content:
# return NewModelForm(content)
#
# return NewModelForm()
#
# return None
#def cleanup_request(self, data, form_instance):
# """Override cleanup_request to drop read-only fields from the input prior to validation.
# This ensures that we don't error out with 'non-existent field' when these fields are supplied,
# and allows for a pragmatic approach to resources which include read-only elements.
#
# I would actually like to be strict and verify the value of correctness of the values in these fields,
# although that gets tricky as it involves validating at the point that we get the model instance.
#
# See here for another example of this approach:
# http://fedoraproject.org/wiki/Cloud_APIs_REST_Style_Guide
# https://www.redhat.com/archives/rest-practices/2010-April/thread.html#00041"""
# read_only_fields = set(self.fields) - set(self.form_instance.fields)
# input_fields = set(data.keys())
#
# clean_data = {}
# for key in input_fields - read_only_fields:
# clean_data[key] = data[key]
#
# return super(ModelResource, self).cleanup_request(clean_data, form_instance)
def cleanup_response(self, data):
"""A munging of Piston's pre-serialization. Returns a dict"""
def _any(thing, fields=()):
"""
Dispatch, all types are routed through here.
"""
ret = None
if isinstance(thing, QuerySet):
ret = _qs(thing, fields=fields)
elif isinstance(thing, (tuple, list)):
ret = _list(thing)
elif isinstance(thing, dict):
ret = _dict(thing)
elif isinstance(thing, int):
ret = thing
elif isinstance(thing, bool):
ret = thing
elif isinstance(thing, type(None)):
ret = thing
elif isinstance(thing, decimal.Decimal):
ret = str(thing)
elif isinstance(thing, Model):
ret = _model(thing, fields=fields)
#elif isinstance(thing, HttpResponse): TRC
# raise HttpStatusCode(thing)
elif inspect.isfunction(thing):
if not inspect.getargspec(thing)[0]:
ret = _any(thing())
elif hasattr(thing, '__emittable__'):
f = thing.__emittable__
if inspect.ismethod(f) and len(inspect.getargspec(f)[0]) == 1:
ret = _any(f())
else:
ret = unicode(thing) # TRC TODO: Change this back!
return ret
def _fk(data, field):
"""
Foreign keys.
"""
return _any(getattr(data, field.name))
def _related(data, fields=()):
"""
Foreign keys.
"""
return [ _model(m, fields) for m in data.iterator() ]
def _m2m(data, field, fields=()):
"""
Many to many (re-route to `_model`.)
"""
return [ _model(m, fields) for m in getattr(data, field.name).iterator() ]
def _method_fields(data, fields):
if not data:
return { }
has = dir(data)
ret = dict()
for field in fields:
if field in has:
ret[field] = getattr(data, field)
return ret
def _model(data, fields=()):
"""
Models. Will respect the `fields` and/or
`exclude` on the handler (see `typemapper`.)
"""
ret = { }
#handler = self.in_typemapper(type(data), self.anonymous) # TRC
handler = None # TRC
get_absolute_url = False
if handler or fields:
v = lambda f: getattr(data, f.attname)
if not fields:
"""
Fields was not specified, try to find teh correct
version in the typemapper we were sent.
"""
mapped = self.in_typemapper(type(data), self.anonymous)
get_fields = set(mapped.fields)
exclude_fields = set(mapped.exclude).difference(get_fields)
if not get_fields:
get_fields = set([ f.attname.replace("_id", "", 1)
for f in data._meta.fields ])
# sets can be negated.
for exclude in exclude_fields:
if isinstance(exclude, basestring):
get_fields.discard(exclude)
elif isinstance(exclude, re._pattern_type):
for field in get_fields.copy():
if exclude.match(field):
get_fields.discard(field)
get_absolute_url = True
else:
get_fields = set(fields)
if 'absolute_url' in get_fields: # MOVED (TRC)
get_absolute_url = True
met_fields = _method_fields(handler, get_fields) # TRC
for f in data._meta.local_fields:
if f.serialize and not any([ p in met_fields for p in [ f.attname, f.name ]]):
if not f.rel:
if f.attname in get_fields:
ret[f.attname] = _any(v(f))
get_fields.remove(f.attname)
else:
if f.attname[:-3] in get_fields:
ret[f.name] = _fk(data, f)
get_fields.remove(f.name)
for mf in data._meta.many_to_many:
if mf.serialize and mf.attname not in met_fields:
if mf.attname in get_fields:
ret[mf.name] = _m2m(data, mf)
get_fields.remove(mf.name)
# try to get the remainder of fields
for maybe_field in get_fields:
if isinstance(maybe_field, (list, tuple)):
model, fields = maybe_field
inst = getattr(data, model, None)
if inst:
if hasattr(inst, 'all'):
ret[model] = _related(inst, fields)
elif callable(inst):
if len(inspect.getargspec(inst)[0]) == 1:
ret[model] = _any(inst(), fields)
else:
ret[model] = _model(inst, fields)
elif maybe_field in met_fields:
# Overriding normal field which has a "resource method"
# so you can alter the contents of certain fields without
# using different names.
ret[maybe_field] = _any(met_fields[maybe_field](data))
else:
maybe = getattr(data, maybe_field, None)
if maybe:
if callable(maybe):
if len(inspect.getargspec(maybe)[0]) == 1:
ret[maybe_field] = _any(maybe())
else:
ret[maybe_field] = _any(maybe)
else:
pass # TRC
#handler_f = getattr(handler or self.handler, maybe_field, None)
#
#if handler_f:
# ret[maybe_field] = _any(handler_f(data))
else:
# Add absolute_url if it exists
get_absolute_url = True
# Add all the fields
for f in data._meta.fields:
if f.attname != 'id':
ret[f.attname] = _any(getattr(data, f.attname))
# Add all the propertiess
klass = data.__class__
for attr in dir(klass):
if not attr.startswith('_') and not attr in ('pk','id') and isinstance(getattr(klass, attr, None), property):
#if attr.endswith('_url') or attr.endswith('_uri'):
# ret[attr] = self.make_absolute(_any(getattr(data, attr)))
#else:
ret[attr] = _any(getattr(data, attr))
#fields = dir(data.__class__) + ret.keys()
#add_ons = [k for k in dir(data) if k not in fields and not k.startswith('_')]
#print add_ons
###print dir(data.__class__)
#from django.db.models import Model
#model_fields = dir(Model)
#for attr in dir(data):
## #if attr.startswith('_'):
## # continue
# if (attr in fields) and not (attr in model_fields) and not attr.startswith('_'):
# print attr, type(getattr(data, attr, None)), attr in fields, attr in model_fields
#for k in add_ons:
# ret[k] = _any(getattr(data, k))
# TRC
# resouce uri
#if self.in_typemapper(type(data), self.anonymous):
# handler = self.in_typemapper(type(data), self.anonymous)
# if hasattr(handler, 'resource_uri'):
# url_id, fields = handler.resource_uri()
# ret['resource_uri'] = permalink( lambda: (url_id,
# (getattr(data, f) for f in fields) ) )()
# TRC
#if hasattr(data, 'get_api_url') and 'resource_uri' not in ret:
# try: ret['resource_uri'] = data.get_api_url()
# except: pass
# absolute uri
if hasattr(data, 'get_absolute_url') and get_absolute_url:
try: ret['absolute_url'] = data.get_absolute_url()
except: pass
#for key, val in ret.items():
# if key.endswith('_url') or key.endswith('_uri'):
# ret[key] = self.add_domain(val)
return ret
def _qs(data, fields=()):
"""
Querysets.
"""
return [ _any(v, fields) for v in data ]
def _list(data):
"""
Lists.
"""
return [ _any(v) for v in data ]
def _dict(data):
"""
Dictionaries.
"""
return dict([ (k, _any(v)) for k, v in data.iteritems() ])
# Kickstart the seralizin'.
return _any(data, self.fields)
def post(self, request, auth, content, *args, **kwargs):
# TODO: test creation on a non-existing resource url
# translated related_field into related_field_id
for related_name in [field.name for field in self.model._meta.fields if isinstance(field, RelatedField)]:
if kwargs.has_key(related_name):
kwargs[related_name + '_id'] = kwargs[related_name]
del kwargs[related_name]
all_kw_args = dict(content.items() + kwargs.items())
if args:
instance = self.model(pk=args[-1], **all_kw_args)
else:
instance = self.model(**all_kw_args)
instance.save()
headers = {}
if hasattr(instance, 'get_absolute_url'):
headers['Location'] = instance.get_absolute_url()
return Response(status.HTTP_201_CREATED, instance, headers)
def get(self, request, auth, *args, **kwargs):
try:
if args:
# If we have any none kwargs then assume the last represents the primrary key
instance = self.model.objects.get(pk=args[-1], **kwargs)
else:
# Otherwise assume the kwargs uniquely identify the model
instance = self.model.objects.get(**kwargs)
except self.model.DoesNotExist:
raise ResponseException(status.HTTP_404_NOT_FOUND)
return instance
def put(self, request, auth, content, *args, **kwargs):
# TODO: update on the url of a non-existing resource url doesn't work correctly at the moment - will end up with a new url
try:
if args:
# If we have any none kwargs then assume the last represents the primrary key
instance = self.model.objects.get(pk=args[-1], **kwargs)
else:
# Otherwise assume the kwargs uniquely identify the model
instance = self.model.objects.get(**kwargs)
for (key, val) in content.items():
setattr(instance, key, val)
except self.model.DoesNotExist:
instance = self.model(**content)
instance.save()
instance.save()
return instance
def delete(self, request, auth, *args, **kwargs):
try:
if args:
# If we have any none kwargs then assume the last represents the primrary key
instance = self.model.objects.get(pk=args[-1], **kwargs)
else:
# Otherwise assume the kwargs uniquely identify the model
instance = self.model.objects.get(**kwargs)
except self.model.DoesNotExist:
raise ResponseException(status.HTTP_404_NOT_FOUND, None, {})
instance.delete()
return
class RootModelResource(ModelResource):
"""A Resource which provides default operations for list and create."""
allowed_methods = ('GET', 'POST')
queryset = None
def get(self, request, auth, *args, **kwargs):
queryset = self.queryset if self.queryset else self.model.objects.all()
return queryset.filter(**kwargs)
class QueryModelResource(ModelResource):
"""Resource with default operations for list.
TODO: provide filter/order/num_results/paging, and a create operation to create queries."""
allowed_methods = ('GET',)
queryset = None
def get_form(self, data=None):
return None
def get(self, request, auth, *args, **kwargs):
queryset = self.queryset if self.queryset else self.model.objects.all()
return queryset.filer(**kwargs)