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