django-rest-framework/djangorestframework/resource.py
2011-05-10 12:59:13 +01:00

253 lines
9.8 KiB
Python

from django.db.models import Model
from django.db.models.query import QuerySet
from django.db.models.fields.related import RelatedField
import decimal
import inspect
import re
# TODO: Replace this with new Serializer code based on Forms API.
class Resource(object):
"""A Resource determines how an object maps to a serializable entity.
Objects that a resource can act on include plain Python object instances, Django Models, and Django QuerySets."""
# 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
@classmethod
def object_to_serializable(self, data):
"""A (horrible) 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, '__rendertable__'):
f = thing.__rendertable__
if inspect.ismethod(f) and len(inspect.getargspec(f)[0]) == 1:
ret = _any(f())
else:
ret = unicode(thing) # TRC
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 fields:
v = lambda f: getattr(data, f.attname)
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)