555 lines
24 KiB
Python
555 lines
24 KiB
Python
import copy
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import types
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import sys
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import os
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from itertools import izip
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import django.db.models.manipulators # Imported to register signal handler.
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import django.db.models.manager # Ditto.
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from django.core import validators
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from django.core.exceptions import ObjectDoesNotExist, MultipleObjectsReturned, FieldError
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from django.db.models.fields import AutoField, ImageField, FieldDoesNotExist
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from django.db.models.fields.related import OneToOneRel, ManyToOneRel, OneToOneField
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from django.db.models.query import delete_objects, Q
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from django.db.models.options import Options, AdminOptions
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from django.db import connection, transaction
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from django.db.models import signals
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from django.db.models.loading import register_models, get_model
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from django.dispatch import dispatcher
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from django.utils.datastructures import SortedDict
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from django.utils.functional import curry
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from django.utils.encoding import smart_str, force_unicode, smart_unicode
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from django.conf import settings
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try:
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set
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except NameError:
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from sets import Set as set # Python 2.3 fallback
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class ModelBase(type):
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"Metaclass for all models"
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def __new__(cls, name, bases, attrs):
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# If this isn't a subclass of Model, don't do anything special.
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try:
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parents = [b for b in bases if issubclass(b, Model)]
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except NameError:
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# 'Model' isn't defined yet, meaning we're looking at Django's own
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# Model class, defined below.
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parents = []
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if not parents:
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return super(ModelBase, cls).__new__(cls, name, bases, attrs)
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# Create the class.
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module = attrs.pop('__module__')
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new_class = type.__new__(cls, name, bases, {'__module__': module})
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attr_meta = attrs.pop('Meta', None)
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abstract = getattr(attr_meta, 'abstract', False)
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if not attr_meta:
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meta = getattr(new_class, 'Meta', None)
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else:
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meta = attr_meta
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base_meta = getattr(new_class, '_meta', None)
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new_class.add_to_class('_meta', Options(meta))
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if not abstract:
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new_class.add_to_class('DoesNotExist',
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subclass_exception('DoesNotExist', ObjectDoesNotExist, module))
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new_class.add_to_class('MultipleObjectsReturned',
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subclass_exception('MultipleObjectsReturned', MultipleObjectsReturned, module))
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if base_meta and not base_meta.abstract:
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# Non-abstract child classes inherit some attributes from their
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# non-abstract parent (unless an ABC comes before it in the
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# method resolution order).
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if not hasattr(meta, 'ordering'):
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new_class._meta.ordering = base_meta.ordering
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if not hasattr(meta, 'get_latest_by'):
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new_class._meta.get_latest_by = base_meta.get_latest_by
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old_default_mgr = None
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if getattr(new_class, '_default_manager', None):
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# We have a parent who set the default manager.
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if new_class._default_manager.model._meta.abstract:
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old_default_mgr = new_class._default_manager
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new_class._default_manager = None
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if getattr(new_class._meta, 'app_label', None) is None:
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# Figure out the app_label by looking one level up.
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# For 'django.contrib.sites.models', this would be 'sites'.
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model_module = sys.modules[new_class.__module__]
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new_class._meta.app_label = model_module.__name__.split('.')[-2]
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# Bail out early if we have already created this class.
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m = get_model(new_class._meta.app_label, name, False)
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if m is not None:
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return m
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# Add all attributes to the class.
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for obj_name, obj in attrs.items():
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new_class.add_to_class(obj_name, obj)
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# Do the appropriate setup for any model parents.
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o2o_map = dict([(f.rel.to, f) for f in new_class._meta.local_fields
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if isinstance(f, OneToOneField)])
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for base in parents:
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if not hasattr(base, '_meta'):
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# Things without _meta aren't functional models, so they're
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# uninteresting parents.
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continue
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if not base._meta.abstract:
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if base in o2o_map:
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field = o2o_map[base]
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field.primary_key = True
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new_class._meta.setup_pk(field)
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else:
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attr_name = '%s_ptr' % base._meta.module_name
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field = OneToOneField(base, name=attr_name,
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auto_created=True, parent_link=True)
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new_class.add_to_class(attr_name, field)
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new_class._meta.parents[base] = field
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else:
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# The abstract base class case.
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names = set([f.name for f in new_class._meta.local_fields + new_class._meta.many_to_many])
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for field in base._meta.local_fields + base._meta.local_many_to_many:
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if field.name in names:
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raise FieldError('Local field %r in class %r clashes with field of similar name from abstract base class %r'
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% (field.name, name, base.__name__))
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new_class.add_to_class(field.name, copy.deepcopy(field))
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if abstract:
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# Abstract base models can't be instantiated and don't appear in
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# the list of models for an app. We do the final setup for them a
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# little differently from normal models.
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attr_meta.abstract = False
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new_class.Meta = attr_meta
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return new_class
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if old_default_mgr and not new_class._default_manager:
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new_class._default_manager = old_default_mgr._copy_to_model(new_class)
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new_class._prepare()
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register_models(new_class._meta.app_label, new_class)
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# Because of the way imports happen (recursively), we may or may not be
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# the first time this model tries to register with the framework. There
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# should only be one class for each model, so we always return the
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# registered version.
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return get_model(new_class._meta.app_label, name, False)
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def add_to_class(cls, name, value):
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if name == 'Admin':
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assert type(value) == types.ClassType, "%r attribute of %s model must be a class, not a %s object" % (name, cls.__name__, type(value))
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value = AdminOptions(**dict([(k, v) for k, v in value.__dict__.items() if not k.startswith('_')]))
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if hasattr(value, 'contribute_to_class'):
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value.contribute_to_class(cls, name)
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else:
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setattr(cls, name, value)
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def _prepare(cls):
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# Creates some methods once self._meta has been populated.
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opts = cls._meta
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opts._prepare(cls)
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if opts.order_with_respect_to:
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cls.get_next_in_order = curry(cls._get_next_or_previous_in_order, is_next=True)
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cls.get_previous_in_order = curry(cls._get_next_or_previous_in_order, is_next=False)
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setattr(opts.order_with_respect_to.rel.to, 'get_%s_order' % cls.__name__.lower(), curry(method_get_order, cls))
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setattr(opts.order_with_respect_to.rel.to, 'set_%s_order' % cls.__name__.lower(), curry(method_set_order, cls))
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# Give the class a docstring -- its definition.
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if cls.__doc__ is None:
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cls.__doc__ = "%s(%s)" % (cls.__name__, ", ".join([f.attname for f in opts.fields]))
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if hasattr(cls, 'get_absolute_url'):
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cls.get_absolute_url = curry(get_absolute_url, opts, cls.get_absolute_url)
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dispatcher.send(signal=signals.class_prepared, sender=cls)
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class Model(object):
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__metaclass__ = ModelBase
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def __init__(self, *args, **kwargs):
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dispatcher.send(signal=signals.pre_init, sender=self.__class__, args=args, kwargs=kwargs)
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# There is a rather weird disparity here; if kwargs, it's set, then args
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# overrides it. It should be one or the other; don't duplicate the work
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# The reason for the kwargs check is that standard iterator passes in by
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# args, and instantiation for iteration is 33% faster.
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args_len = len(args)
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if args_len > len(self._meta.fields):
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# Daft, but matches old exception sans the err msg.
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raise IndexError("Number of args exceeds number of fields")
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fields_iter = iter(self._meta.fields)
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if not kwargs:
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# The ordering of the izip calls matter - izip throws StopIteration
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# when an iter throws it. So if the first iter throws it, the second
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# is *not* consumed. We rely on this, so don't change the order
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# without changing the logic.
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for val, field in izip(args, fields_iter):
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setattr(self, field.attname, val)
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else:
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# Slower, kwargs-ready version.
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for val, field in izip(args, fields_iter):
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setattr(self, field.attname, val)
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kwargs.pop(field.name, None)
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# Maintain compatibility with existing calls.
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if isinstance(field.rel, ManyToOneRel):
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kwargs.pop(field.attname, None)
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# Now we're left with the unprocessed fields that *must* come from
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# keywords, or default.
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for field in fields_iter:
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if kwargs:
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if isinstance(field.rel, ManyToOneRel):
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try:
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# Assume object instance was passed in.
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rel_obj = kwargs.pop(field.name)
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except KeyError:
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try:
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# Object instance wasn't passed in -- must be an ID.
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val = kwargs.pop(field.attname)
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except KeyError:
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val = field.get_default()
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else:
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# Object instance was passed in. Special case: You can
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# pass in "None" for related objects if it's allowed.
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if rel_obj is None and field.null:
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val = None
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else:
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try:
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val = getattr(rel_obj, field.rel.get_related_field().attname)
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except AttributeError:
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raise TypeError("Invalid value: %r should be a %s instance, not a %s" %
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(field.name, field.rel.to, type(rel_obj)))
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else:
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val = kwargs.pop(field.attname, field.get_default())
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else:
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val = field.get_default()
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setattr(self, field.attname, val)
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if kwargs:
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for prop in kwargs.keys():
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try:
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if isinstance(getattr(self.__class__, prop), property):
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setattr(self, prop, kwargs.pop(prop))
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except AttributeError:
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pass
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if kwargs:
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raise TypeError, "'%s' is an invalid keyword argument for this function" % kwargs.keys()[0]
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dispatcher.send(signal=signals.post_init, sender=self.__class__, instance=self)
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def __repr__(self):
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return smart_str(u'<%s: %s>' % (self.__class__.__name__, unicode(self)))
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def __str__(self):
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if hasattr(self, '__unicode__'):
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return force_unicode(self).encode('utf-8')
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return '%s object' % self.__class__.__name__
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def __eq__(self, other):
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return isinstance(other, self.__class__) and self._get_pk_val() == other._get_pk_val()
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def __ne__(self, other):
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return not self.__eq__(other)
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def __hash__(self):
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return hash(self._get_pk_val())
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def _get_pk_val(self, meta=None):
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if not meta:
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meta = self._meta
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return getattr(self, meta.pk.attname)
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def _set_pk_val(self, value):
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return setattr(self, self._meta.pk.attname, value)
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pk = property(_get_pk_val, _set_pk_val)
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def save(self):
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"""
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Save the current instance. Override this in a subclass if you want to
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control the saving process.
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"""
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self.save_base()
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save.alters_data = True
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def save_base(self, raw=False, cls=None):
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"""
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Does the heavy-lifting involved in saving. Subclasses shouldn't need to
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override this method. It's separate from save() in order to hide the
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need for overrides of save() to pass around internal-only parameters
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('raw' and 'cls').
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"""
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if not cls:
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cls = self.__class__
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meta = self._meta
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signal = True
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dispatcher.send(signal=signals.pre_save, sender=self.__class__,
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instance=self, raw=raw)
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else:
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meta = cls._meta
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signal = False
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# If we are in a raw save, save the object exactly as presented.
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# That means that we don't try to be smart about saving attributes
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# that might have come from the parent class - we just save the
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# attributes we have been given to the class we have been given.
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if not raw:
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for parent, field in meta.parents.items():
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self.save_base(raw, parent)
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setattr(self, field.attname, self._get_pk_val(parent._meta))
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non_pks = [f for f in meta.local_fields if not f.primary_key]
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# First, try an UPDATE. If that doesn't update anything, do an INSERT.
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pk_val = self._get_pk_val(meta)
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# Note: the comparison with '' is required for compatibility with
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# oldforms-style model creation.
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pk_set = pk_val is not None and smart_unicode(pk_val) != u''
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record_exists = True
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manager = cls._default_manager
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if pk_set:
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# Determine whether a record with the primary key already exists.
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if manager.filter(pk=pk_val).extra(select={'a': 1}).values('a').order_by():
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# It does already exist, so do an UPDATE.
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if non_pks:
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values = [(f, None, f.get_db_prep_save(raw and getattr(self, f.attname) or f.pre_save(self, False))) for f in non_pks]
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manager.filter(pk=pk_val)._update(values)
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else:
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record_exists = False
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if not pk_set or not record_exists:
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if not pk_set:
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values = [(f, f.get_db_prep_save(raw and getattr(self, f.attname) or f.pre_save(self, True))) for f in meta.local_fields if not isinstance(f, AutoField)]
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else:
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values = [(f, f.get_db_prep_save(raw and getattr(self, f.attname) or f.pre_save(self, True))) for f in meta.local_fields]
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if meta.order_with_respect_to:
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field = meta.order_with_respect_to
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values.append((meta.get_field_by_name('_order')[0], manager.filter(**{field.name: getattr(self, field.attname)}).count()))
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record_exists = False
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update_pk = bool(meta.has_auto_field and not pk_set)
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if values:
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# Create a new record.
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result = manager._insert(values, return_id=update_pk)
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else:
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# Create a new record with defaults for everything.
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result = manager._insert([(meta.pk, connection.ops.pk_default_value())], return_id=update_pk, raw_values=True)
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if update_pk:
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setattr(self, meta.pk.attname, result)
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transaction.commit_unless_managed()
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if signal:
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dispatcher.send(signal=signals.post_save, sender=self.__class__,
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instance=self, created=(not record_exists), raw=raw)
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save_base.alters_data = True
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def validate(self):
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"""
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First coerces all fields on this instance to their proper Python types.
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Then runs validation on every field. Returns a dictionary of
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field_name -> error_list.
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"""
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error_dict = {}
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invalid_python = {}
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for f in self._meta.fields:
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try:
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setattr(self, f.attname, f.to_python(getattr(self, f.attname, f.get_default())))
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except validators.ValidationError, e:
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error_dict[f.name] = e.messages
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invalid_python[f.name] = 1
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for f in self._meta.fields:
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if f.name in invalid_python:
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continue
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errors = f.validate_full(getattr(self, f.attname, f.get_default()), self.__dict__)
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if errors:
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error_dict[f.name] = errors
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return error_dict
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def _collect_sub_objects(self, seen_objs):
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"""
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Recursively populates seen_objs with all objects related to this object.
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When done, seen_objs will be in the format:
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{model_class: {pk_val: obj, pk_val: obj, ...},
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model_class: {pk_val: obj, pk_val: obj, ...}, ...}
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"""
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pk_val = self._get_pk_val()
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if pk_val in seen_objs.setdefault(self.__class__, {}):
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return
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seen_objs.setdefault(self.__class__, {})[pk_val] = self
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for related in self._meta.get_all_related_objects():
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rel_opts_name = related.get_accessor_name()
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if isinstance(related.field.rel, OneToOneRel):
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try:
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sub_obj = getattr(self, rel_opts_name)
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except ObjectDoesNotExist:
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pass
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else:
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sub_obj._collect_sub_objects(seen_objs)
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else:
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for sub_obj in getattr(self, rel_opts_name).all():
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sub_obj._collect_sub_objects(seen_objs)
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def delete(self):
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assert self._get_pk_val() is not None, "%s object can't be deleted because its %s attribute is set to None." % (self._meta.object_name, self._meta.pk.attname)
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# Find all the objects than need to be deleted
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seen_objs = SortedDict()
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self._collect_sub_objects(seen_objs)
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# Actually delete the objects
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delete_objects(seen_objs)
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delete.alters_data = True
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def _get_FIELD_display(self, field):
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value = getattr(self, field.attname)
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return force_unicode(dict(field.choices).get(value, value), strings_only=True)
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def _get_next_or_previous_by_FIELD(self, field, is_next, **kwargs):
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op = is_next and 'gt' or 'lt'
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order = not is_next and '-' or ''
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param = smart_str(getattr(self, field.attname))
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q = Q(**{'%s__%s' % (field.name, op): param})
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q = q|Q(**{field.name: param, 'pk__%s' % op: self.pk})
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qs = self.__class__._default_manager.filter(**kwargs).filter(q).order_by('%s%s' % (order, field.name), '%spk' % order)
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try:
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return qs[0]
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except IndexError:
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raise self.DoesNotExist, "%s matching query does not exist." % self.__class__._meta.object_name
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def _get_next_or_previous_in_order(self, is_next):
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cachename = "__%s_order_cache" % is_next
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if not hasattr(self, cachename):
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qn = connection.ops.quote_name
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op = is_next and '>' or '<'
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order = not is_next and '-_order' or '_order'
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order_field = self._meta.order_with_respect_to
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# FIXME: When querysets support nested queries, this can be turned
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# into a pure queryset operation.
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where = ['%s %s (SELECT %s FROM %s WHERE %s=%%s)' % \
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(qn('_order'), op, qn('_order'),
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qn(self._meta.db_table), qn(self._meta.pk.column))]
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params = [self.pk]
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obj = self._default_manager.filter(**{order_field.name: getattr(self, order_field.attname)}).extra(where=where, params=params).order_by(order)[:1].get()
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setattr(self, cachename, obj)
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return getattr(self, cachename)
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def _get_FIELD_filename(self, field):
|
|
if getattr(self, field.attname): # value is not blank
|
|
return os.path.join(settings.MEDIA_ROOT, getattr(self, field.attname))
|
|
return ''
|
|
|
|
def _get_FIELD_url(self, field):
|
|
if getattr(self, field.attname): # value is not blank
|
|
import urlparse
|
|
return urlparse.urljoin(settings.MEDIA_URL, getattr(self, field.attname)).replace('\\', '/')
|
|
return ''
|
|
|
|
def _get_FIELD_size(self, field):
|
|
return os.path.getsize(self._get_FIELD_filename(field))
|
|
|
|
def _save_FIELD_file(self, field, filename, raw_contents, save=True):
|
|
directory = field.get_directory_name()
|
|
try: # Create the date-based directory if it doesn't exist.
|
|
os.makedirs(os.path.join(settings.MEDIA_ROOT, directory))
|
|
except OSError: # Directory probably already exists.
|
|
pass
|
|
filename = field.get_filename(filename)
|
|
|
|
# If the filename already exists, keep adding an underscore to the name of
|
|
# the file until the filename doesn't exist.
|
|
while os.path.exists(os.path.join(settings.MEDIA_ROOT, filename)):
|
|
try:
|
|
dot_index = filename.rindex('.')
|
|
except ValueError: # filename has no dot
|
|
filename += '_'
|
|
else:
|
|
filename = filename[:dot_index] + '_' + filename[dot_index:]
|
|
|
|
# Write the file to disk.
|
|
setattr(self, field.attname, filename)
|
|
|
|
full_filename = self._get_FIELD_filename(field)
|
|
fp = open(full_filename, 'wb')
|
|
fp.write(raw_contents)
|
|
fp.close()
|
|
|
|
# Save the width and/or height, if applicable.
|
|
if isinstance(field, ImageField) and (field.width_field or field.height_field):
|
|
from django.utils.images import get_image_dimensions
|
|
width, height = get_image_dimensions(full_filename)
|
|
if field.width_field:
|
|
setattr(self, field.width_field, width)
|
|
if field.height_field:
|
|
setattr(self, field.height_field, height)
|
|
|
|
# Save the object because it has changed unless save is False
|
|
if save:
|
|
self.save()
|
|
|
|
_save_FIELD_file.alters_data = True
|
|
|
|
def _get_FIELD_width(self, field):
|
|
return self._get_image_dimensions(field)[0]
|
|
|
|
def _get_FIELD_height(self, field):
|
|
return self._get_image_dimensions(field)[1]
|
|
|
|
def _get_image_dimensions(self, field):
|
|
cachename = "__%s_dimensions_cache" % field.name
|
|
if not hasattr(self, cachename):
|
|
from django.utils.images import get_image_dimensions
|
|
filename = self._get_FIELD_filename(field)
|
|
setattr(self, cachename, get_image_dimensions(filename))
|
|
return getattr(self, cachename)
|
|
|
|
############################################
|
|
# HELPER FUNCTIONS (CURRIED MODEL METHODS) #
|
|
############################################
|
|
|
|
# ORDERING METHODS #########################
|
|
|
|
def method_set_order(ordered_obj, self, id_list):
|
|
rel_val = getattr(self, ordered_obj._meta.order_with_respect_to.rel.field_name)
|
|
order_name = ordered_obj._meta.order_with_respect_to.name
|
|
# FIXME: It would be nice if there was an "update many" version of update
|
|
# for situations like this.
|
|
for i, j in enumerate(id_list):
|
|
ordered_obj.objects.filter(**{'pk': j, order_name: rel_val}).update(_order=i)
|
|
transaction.commit_unless_managed()
|
|
|
|
def method_get_order(ordered_obj, self):
|
|
rel_val = getattr(self, ordered_obj._meta.order_with_respect_to.rel.field_name)
|
|
order_name = ordered_obj._meta.order_with_respect_to.name
|
|
pk_name = ordered_obj._meta.pk.name
|
|
return [r[pk_name] for r in
|
|
ordered_obj.objects.filter(**{order_name: rel_val}).values(pk_name)]
|
|
|
|
##############################################
|
|
# HELPER FUNCTIONS (CURRIED MODEL FUNCTIONS) #
|
|
##############################################
|
|
|
|
def get_absolute_url(opts, func, self, *args, **kwargs):
|
|
return settings.ABSOLUTE_URL_OVERRIDES.get('%s.%s' % (opts.app_label, opts.module_name), func)(self, *args, **kwargs)
|
|
|
|
########
|
|
# MISC #
|
|
########
|
|
|
|
class Empty(object):
|
|
pass
|
|
|
|
if sys.version_info < (2, 5):
|
|
# Prior to Python 2.5, Exception was an old-style class
|
|
def subclass_exception(name, parent, unused):
|
|
return types.ClassType(name, (parent,), {})
|
|
|
|
else:
|
|
def subclass_exception(name, parent, module):
|
|
return type(name, (parent,), {'__module__': module})
|
|
|