-from UserDict import DictMixin
-
from django import forms
from django.contrib.contenttypes.models import ContentType
from django.contrib.contenttypes import generic
-from django.core.exceptions import ObjectDoesNotExist
+from django.core.exceptions import ValidationError
from django.core.validators import RegexValidator
from django.db import models
from django.utils import simplejson as json
from philo.models.fields import JSONField
from philo.signals import entity_class_prepared
from philo.utils import ContentTypeRegistryLimiter, ContentTypeSubclassLimiter
+from philo.utils.entities import AttributeMapper, TreeAttributeMapper
from philo.validators import json_validator
+__all__ = ('Tag', 'value_content_type_limiter', 'register_value_model', 'unregister_value_model', 'JSONValue', 'ForeignKeyValue', 'ManyToManyValue', 'Attribute', 'Entity', 'TreeEntity', 'SlugTreeEntity')
+
+
class Tag(models.Model):
+ """A simple, generic model for tagging."""
+ #: A CharField (max length 255) which contains the name of the tag.
name = models.CharField(max_length=255)
+ #: A CharField (max length 255) which contains the tag's unique slug.
slug = models.SlugField(max_length=255, unique=True)
def __unicode__(self):
+ """Returns the value of the :attr:`name` field"""
return self.name
class Meta:
ordering = ('name',)
-class Titled(models.Model):
- title = models.CharField(max_length=255)
- slug = models.SlugField(max_length=255)
-
- def __unicode__(self):
- return self.title
-
- class Meta:
- abstract = True
-
-
-#: An instance of :class:`ContentTypeRegistryLimiter` which is used to track the content types which can be related to by ForeignKeyValues and ManyToManyValues.
+#: An instance of :class:`.ContentTypeRegistryLimiter` which is used to track the content types which can be related to by :class:`ForeignKeyValue`\ s and :class:`ManyToManyValue`\ s.
value_content_type_limiter = ContentTypeRegistryLimiter()
abstract = True
-#: An instance of :class:`ContentTypeSubclassLimiter` which is used to track the content types which are considered valid value models for an :class:`Attribute`.
+#: An instance of :class:`.ContentTypeSubclassLimiter` which is used to track the content types which are considered valid value models for an :class:`Attribute`.
attribute_value_limiter = ContentTypeSubclassLimiter(AttributeValue)
class Attribute(models.Model):
- """Represents an arbitrary key/value pair on an arbitrary :class:`Model` where the key consists of word characters and the value is a subclass of :class:`AttributeValue`."""
+ """
+ :class:`Attribute`\ s exist primarily to let arbitrary data be attached to arbitrary model instances without altering the database schema and without guaranteeing that the data will be available on every instance of that model.
+
+ Generally, :class:`Attribute`\ s will not be accessed as models; instead, they will be accessed through the :attr:`Entity.attributes` property, which allows direct dictionary getting and setting of the value of an :class:`Attribute` with its key.
+
+ """
entity_content_type = models.ForeignKey(ContentType, related_name='attribute_entity_set', verbose_name='Entity type')
entity_object_id = models.PositiveIntegerField(verbose_name='Entity ID', db_index=True)
def __unicode__(self):
return u'"%s": %s' % (self.key, self.value)
+ def set_value(self, value, value_class=JSONValue):
+ """Given a value and a value class, sets up self.value appropriately."""
+ if isinstance(self.value, value_class):
+ val = self.value
+ else:
+ if isinstance(self.value, models.Model):
+ self.value.delete()
+ val = value_class()
+
+ val.set_value(value)
+ val.save()
+
+ self.value = val
+ self.save()
+
class Meta:
app_label = 'philo'
unique_together = (('key', 'entity_content_type', 'entity_object_id'), ('value_content_type', 'value_object_id'))
-class QuerySetMapper(object, DictMixin):
- def __init__(self, queryset, passthrough=None):
- self.queryset = queryset
- self.passthrough = passthrough
-
- def __getitem__(self, key):
- try:
- value = self.queryset.get(key__exact=key).value
- except ObjectDoesNotExist:
- if self.passthrough is not None:
- return self.passthrough.__getitem__(key)
- raise KeyError
- else:
- if value is not None:
- return value.value
- return value
-
- def keys(self):
- keys = set(self.queryset.values_list('key', flat=True).distinct())
- if self.passthrough is not None:
- keys |= set(self.passthrough.keys())
- return list(keys)
-
-
class EntityOptions(object):
def __init__(self, options):
if options is not None:
attribute_set = generic.GenericRelation(Attribute, content_type_field='entity_content_type', object_id_field='entity_object_id')
- @property
- def attributes(self):
+ def get_attribute_mapper(self, mapper=AttributeMapper):
"""
- Property that returns a dictionary-like object which can be used to retrieve related :class:`Attribute`\ s' values directly.
+ Returns an :class:`.AttributeMapper` which can be used to retrieve related :class:`Attribute`\ s' values directly.
Example::
u'eggs'
"""
-
- return QuerySetMapper(self.attribute_set.all())
+ return mapper(self)
+
+ @property
+ def attributes(self):
+ if not hasattr(self, '_attributes'):
+ self._attributes = self.get_attribute_mapper()
+ return self._attributes
class Meta:
abstract = True
-class TreeManager(models.Manager):
+class TreeEntityBase(MPTTModelBase, EntityBase):
+ def __new__(meta, name, bases, attrs):
+ attrs['_mptt_meta'] = MPTTOptions(attrs.pop('MPTTMeta', None))
+ cls = EntityBase.__new__(meta, name, bases, attrs)
+
+ return meta.register(cls)
+
+
+class TreeEntityManager(models.Manager):
use_for_related_fields = True
- def get_with_path(self, path, root=None, absolute_result=True, pathsep='/', field='slug'):
+ def get_with_path(self, path, root=None, absolute_result=True, pathsep='/', field='pk'):
"""
- If ``absolute_result`` is ``True``, returns the object at ``path`` (starting at ``root``) or raises a :class:`DoesNotExist` exception. Otherwise, returns a tuple containing the deepest object found along ``path`` (or ``root`` if no deeper object is found) and the remainder of the path after that object as a string (or None if there is no remaining path).
+ If ``absolute_result`` is ``True``, returns the object at ``path`` (starting at ``root``) or raises an :class:`~django.core.exceptions.ObjectDoesNotExist` exception. Otherwise, returns a tuple containing the deepest object found along ``path`` (or ``root`` if no deeper object is found) and the remainder of the path after that object as a string (or None if there is no remaining path).
.. note:: If you are looking for something with an exact path, it is faster to use absolute_result=True, unless the path depth is over ~40, in which case the high cost of the absolute query may make a binary search (i.e. non-absolute) faster.
:param absolute_result: Whether to return an absolute result or do a binary search
:param pathsep: The path separator used in ``path``
:param field: The field on the model which should be queried for ``path`` segment matching.
- :returns: An instance if absolute_result is True or (instance, remaining_path) otherwise.
+ :returns: An instance if ``absolute_result`` is ``True`` or an (instance, remaining_path) tuple otherwise.
+ :raises django.core.exceptions.ObjectDoesNotExist: if no object can be found matching the input parameters.
"""
return find_obj(segments, len(segments)/2 or len(segments))
-class TreeModel(MPTTModel):
- objects = TreeManager()
+class TreeEntity(Entity, MPTTModel):
+ """An abstract subclass of Entity which represents a tree relationship."""
+
+ __metaclass__ = TreeEntityBase
+ objects = TreeEntityManager()
parent = models.ForeignKey('self', related_name='children', null=True, blank=True)
- slug = models.SlugField(max_length=255)
- def get_path(self, root=None, pathsep='/', field='slug'):
+ def get_path(self, root=None, pathsep='/', field='pk', memoize=True):
"""
:param root: Only return the path since this object.
:param pathsep: The path separator to use when constructing an instance's path
:param field: The field to pull path information from for each ancestor.
+ :param memoize: Whether to use memoized results. Since, in most cases, the ancestors of a TreeEntity will not change over the course of an instance's lifetime, this defaults to ``True``.
:returns: A string representation of an object's path.
"""
if root == self:
return ''
+ if root is None and self.is_root_node():
+ return getattr(self, field, '?')
+
if root is not None and not self.is_descendant_of(root):
raise AncestorDoesNotExist(root)
+ if memoize:
+ memo_args = (getattr(self, "%s_id" % self._mptt_meta.parent_attr), getattr(root, 'pk', None), pathsep, getattr(self, field, '?'))
+ try:
+ return self._path_memo[memo_args]
+ except AttributeError:
+ self._path_memo = {}
+ except KeyError:
+ pass
+
qs = self.get_ancestors(include_self=True)
if root is not None:
qs = qs.filter(**{'%s__gt' % self._mptt_meta.level_attr: root.get_level()})
- return pathsep.join([getattr(parent, field, '?') for parent in qs])
- path = property(get_path)
-
- def __unicode__(self):
- return self.path
-
- class Meta:
- unique_together = (('parent', 'slug'),)
- abstract = True
-
-
-class TreeEntityBase(MPTTModelBase, EntityBase):
- def __new__(meta, name, bases, attrs):
- attrs['_mptt_meta'] = MPTTOptions(attrs.pop('MPTTMeta', None))
- cls = EntityBase.__new__(meta, name, bases, attrs)
+ path = pathsep.join([getattr(parent, field, '?') for parent in qs])
- return meta.register(cls)
-
-
-class TreeEntity(Entity, TreeModel):
- """An abstract subclass of Entity which represents a tree relationship."""
-
- __metaclass__ = TreeEntityBase
+ if memoize:
+ self._path_memo[memo_args] = path
+
+ return path
+ path = property(get_path)
- @property
- def attributes(self):
+ def get_attribute_mapper(self, mapper=None):
"""
- Property that returns a dictionary-like object which can be used to retrieve related :class:`Attribute`\ s' values directly. If an attribute with a given key is not related to the :class:`Entity`, then the object will check the parent's attributes.
+ Returns a :class:`.TreeAttributeMapper` or :class:`.AttributeMapper` which can be used to retrieve related :class:`Attribute`\ s' values directly. If an :class:`Attribute` with a given key is not related to the :class:`Entity`, then the mapper will check the parent's attributes.
Example::
u'eggs'
"""
-
- if self.parent:
- return QuerySetMapper(self.attribute_set.all(), passthrough=self.parent.attributes)
- return super(TreeEntity, self).attributes
+ if mapper is None:
+ if self.parent:
+ mapper = TreeAttributeMapper
+ else:
+ mapper = AttributeMapper
+ return super(TreeEntity, self).get_attribute_mapper(mapper)
+
+ def __unicode__(self):
+ return self.path
+
+ class Meta:
+ abstract = True
+
+
+class SlugTreeEntityManager(TreeEntityManager):
+ def get_with_path(self, path, root=None, absolute_result=True, pathsep='/', field='slug'):
+ return super(SlugTreeEntityManager, self).get_with_path(path, root, absolute_result, pathsep, field)
+
+
+class SlugTreeEntity(TreeEntity):
+ objects = SlugTreeEntityManager()
+ slug = models.SlugField(max_length=255)
+
+ def get_path(self, root=None, pathsep='/', field='slug', memoize=True):
+ return super(SlugTreeEntity, self).get_path(root, pathsep, field, memoize)
+ path = property(get_path)
+
+ def clean(self):
+ if self.parent is None:
+ try:
+ self._default_manager.exclude(pk=self.pk).get(slug=self.slug, parent__isnull=True)
+ except self.DoesNotExist:
+ pass
+ else:
+ raise ValidationError(self.unique_error_message(self.__class__, ('parent', 'slug')))
class Meta:
+ unique_together = ('parent', 'slug')
abstract = True
\ No newline at end of file
git.ithinksw.org / philo.git / blobdiff