+from django import forms
from django.db import models
from django.contrib.contenttypes.models import ContentType
from django.contrib.contenttypes import generic
-from django.utils import simplejson as json
from django.core.exceptions import ObjectDoesNotExist
-from philo.utils import ContentTypeRegistryLimiter
+from django.core.validators import RegexValidator
+from django.utils import simplejson as json
+from django.utils.encoding import force_unicode
+from philo.exceptions import AncestorDoesNotExist
+from philo.models.fields import JSONField
+from philo.utils import ContentTypeRegistryLimiter, ContentTypeSubclassLimiter
+from philo.signals import entity_class_prepared
+from philo.validators import json_validator
from UserDict import DictMixin
+from mptt.models import MPTTModel, MPTTModelBase, MPTTOptions
class Tag(models.Model):
- name = models.CharField(max_length=250)
- slug = models.SlugField(unique=True)
+ name = models.CharField(max_length=255)
+ slug = models.SlugField(max_length=255, unique=True)
def __unicode__(self):
return self.name
class Meta:
app_label = 'philo'
+ ordering = ('name',)
class Titled(models.Model):
abstract = True
-class Attribute(models.Model):
- entity_content_type = models.ForeignKey(ContentType, verbose_name='Entity type')
- entity_object_id = models.PositiveIntegerField(verbose_name='Entity ID')
- entity = generic.GenericForeignKey('entity_content_type', 'entity_object_id')
- key = models.CharField(max_length=255)
- json_value = models.TextField(verbose_name='Value (JSON)', help_text='This value must be valid JSON.')
-
- def get_value(self):
- return json.loads(self.json_value)
+value_content_type_limiter = ContentTypeRegistryLimiter()
+
+
+def register_value_model(model):
+ value_content_type_limiter.register_class(model)
+
+
+register_value_model(Tag)
+
+
+def unregister_value_model(model):
+ value_content_type_limiter.unregister_class(model)
+
+
+class AttributeValue(models.Model):
+ attribute_set = generic.GenericRelation('Attribute', content_type_field='value_content_type', object_id_field='value_object_id')
def set_value(self, value):
- self.json_value = json.dumps(value)
+ raise NotImplementedError
- def delete_value(self):
- self.json_value = json.dumps(None)
+ def value_formfields(self, **kwargs):
+ """Define any formfields that would be used to construct an instance of this value."""
+ raise NotImplementedError
- value = property(get_value, set_value, delete_value)
+ def construct_instance(self, **kwargs):
+ """Apply cleaned data from the formfields generated by valid_formfields to oneself."""
+ raise NotImplementedError
def __unicode__(self):
- return u'"%s": %s' % (self.key, self.value)
+ return unicode(self.value)
class Meta:
- app_label = 'philo'
+ abstract = True
-value_content_type_limiter = ContentTypeRegistryLimiter()
+attribute_value_limiter = ContentTypeSubclassLimiter(AttributeValue)
-def register_value_model(model):
- value_content_type_limiter.register_class(model)
+class JSONValue(AttributeValue):
+ value = JSONField(verbose_name='Value (JSON)', help_text='This value must be valid JSON.', default='null', db_index=True)
+
+ def __unicode__(self):
+ return force_unicode(self.value)
+
+ def value_formfields(self):
+ kwargs = {'initial': self.value_json}
+ field = self._meta.get_field('value')
+ return {field.name: field.formfield(**kwargs)}
+
+ def construct_instance(self, **kwargs):
+ field_name = self._meta.get_field('value').name
+ self.set_value(kwargs.pop(field_name, None))
+
+ def set_value(self, value):
+ self.value = value
+
+ class Meta:
+ app_label = 'philo'
-def unregister_value_model(model):
- value_content_type_limiter.unregister_class(model)
+class ForeignKeyValue(AttributeValue):
+ content_type = models.ForeignKey(ContentType, limit_choices_to=value_content_type_limiter, verbose_name='Value type', null=True, blank=True)
+ object_id = models.PositiveIntegerField(verbose_name='Value ID', null=True, blank=True, db_index=True)
+ value = generic.GenericForeignKey()
+
+ def value_formfields(self):
+ field = self._meta.get_field('content_type')
+ fields = {field.name: field.formfield(initial=getattr(self.content_type, 'pk', None))}
+
+ if self.content_type:
+ kwargs = {
+ 'initial': self.object_id,
+ 'required': False,
+ 'queryset': self.content_type.model_class()._default_manager.all()
+ }
+ fields['value'] = forms.ModelChoiceField(**kwargs)
+ return fields
+
+ def construct_instance(self, **kwargs):
+ field_name = self._meta.get_field('content_type').name
+ ct = kwargs.pop(field_name, None)
+ if ct is None or ct != self.content_type:
+ self.object_id = None
+ self.content_type = ct
+ else:
+ value = kwargs.pop('value', None)
+ self.set_value(value)
+ if value is None:
+ self.content_type = ct
+
+ def set_value(self, value):
+ self.value = value
+
+ class Meta:
+ app_label = 'philo'
+class ManyToManyValue(AttributeValue):
+ content_type = models.ForeignKey(ContentType, limit_choices_to=value_content_type_limiter, verbose_name='Value type', null=True, blank=True)
+ values = models.ManyToManyField(ForeignKeyValue, blank=True, null=True)
+
+ def get_object_ids(self):
+ return self.values.values_list('object_id', flat=True)
+ object_ids = property(get_object_ids)
+
+ def set_value(self, value):
+ # Value must be a queryset. Watch out for ModelMultipleChoiceField;
+ # it returns its value as a list if empty.
+
+ self.content_type = ContentType.objects.get_for_model(value.model)
+
+ # Before we can fiddle with the many-to-many to foreignkeyvalues, we need
+ # a pk.
+ if self.pk is None:
+ self.save()
+
+ object_ids = value.values_list('id', flat=True)
+
+ # These lines shouldn't be necessary; however, if object_ids is an EmptyQuerySet,
+ # the code (specifically the object_id__in query) won't work without them. Unclear why...
+ # TODO: is this still the case?
+ if not object_ids:
+ self.values.all().delete()
+ else:
+ self.values.exclude(object_id__in=object_ids, content_type=self.content_type).delete()
+
+ current_ids = self.object_ids
+
+ for object_id in object_ids:
+ if object_id in current_ids:
+ continue
+ self.values.create(content_type=self.content_type, object_id=object_id)
+
+ def get_value(self):
+ if self.content_type is None:
+ return None
+
+ # HACK to be safely explicit until http://code.djangoproject.com/ticket/15145 is resolved
+ object_ids = self.object_ids
+ manager = self.content_type.model_class()._default_manager
+ if not object_ids:
+ return manager.none()
+ return manager.filter(id__in=self.object_ids)
+
+ value = property(get_value, set_value)
+
+ def value_formfields(self):
+ field = self._meta.get_field('content_type')
+ fields = {field.name: field.formfield(initial=getattr(self.content_type, 'pk', None))}
+
+ if self.content_type:
+ kwargs = {
+ 'initial': self.object_ids,
+ 'required': False,
+ 'queryset': self.content_type.model_class()._default_manager.all()
+ }
+ fields['value'] = forms.ModelMultipleChoiceField(**kwargs)
+ return fields
+
+ def construct_instance(self, **kwargs):
+ field_name = self._meta.get_field('content_type').name
+ ct = kwargs.pop(field_name, None)
+ if ct is None or ct != self.content_type:
+ self.values.clear()
+ self.content_type = ct
+ else:
+ value = kwargs.get('value', None)
+ if not value:
+ value = self.content_type.model_class()._default_manager.none()
+ self.set_value(value)
+ construct_instance.alters_data = True
+
+ class Meta:
+ app_label = 'philo'
+
-class Relationship(models.Model):
- entity_content_type = models.ForeignKey(ContentType, related_name='relationship_entity_set', verbose_name='Entity type')
- entity_object_id = models.PositiveIntegerField(verbose_name='Entity ID')
+class Attribute(models.Model):
+ 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)
entity = generic.GenericForeignKey('entity_content_type', 'entity_object_id')
- key = models.CharField(max_length=255)
- value_content_type = models.ForeignKey(ContentType, related_name='relationship_value_set', limit_choices_to=value_content_type_limiter, verbose_name='Value type')
- value_object_id = models.PositiveIntegerField(verbose_name='Value ID')
+
+ value_content_type = models.ForeignKey(ContentType, related_name='attribute_value_set', limit_choices_to=attribute_value_limiter, verbose_name='Value type', null=True, blank=True)
+ value_object_id = models.PositiveIntegerField(verbose_name='Value ID', null=True, blank=True, db_index=True)
value = generic.GenericForeignKey('value_content_type', 'value_object_id')
+ key = models.CharField(max_length=255, validators=[RegexValidator("\w+")], help_text="Must contain one or more alphanumeric characters or underscores.", db_index=True)
+
def __unicode__(self):
return u'"%s": %s' % (self.key, self.value)
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 __getitem__(self, key):
try:
- return self.queryset.get(key__exact=key).value
+ 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())
return list(keys)
+class EntityOptions(object):
+ def __init__(self, options):
+ if options is not None:
+ for key, value in options.__dict__.items():
+ setattr(self, key, value)
+ if not hasattr(self, 'proxy_fields'):
+ self.proxy_fields = []
+
+ def add_proxy_field(self, proxy_field):
+ self.proxy_fields.append(proxy_field)
+
+
+class EntityBase(models.base.ModelBase):
+ def __new__(cls, name, bases, attrs):
+ entity_meta = attrs.pop('EntityMeta', None)
+ new = super(EntityBase, cls).__new__(cls, name, bases, attrs)
+ new.add_to_class('_entity_meta', EntityOptions(entity_meta))
+ entity_class_prepared.send(sender=new)
+ return new
+
+
class Entity(models.Model):
+ __metaclass__ = EntityBase
+
attribute_set = generic.GenericRelation(Attribute, content_type_field='entity_content_type', object_id_field='entity_object_id')
- relationship_set = generic.GenericRelation(Relationship, content_type_field='entity_content_type', object_id_field='entity_object_id')
@property
def attributes(self):
- return QuerySetMapper(self.attribute_set)
-
- @property
- def relationships(self):
- return QuerySetMapper(self.relationship_set)
+ return QuerySetMapper(self.attribute_set.all())
class Meta:
abstract = True
class TreeManager(models.Manager):
use_for_related_fields = True
- def roots(self):
- return self.filter(parent__isnull=True)
-
- def get_with_path(self, path, root=None, absolute_result=True, pathsep='/'):
+ def get_with_path(self, path, root=None, absolute_result=True, pathsep='/', field='slug'):
"""
- Returns the object with the path, or None if there is no object with that path,
- unless absolute_result is set to False, in which case it returns a tuple containing
- the deepest object found along the path, and the remainder of the path after that
- object as a string (or None in the case that there is no remaining path).
+ Returns the object with the path, unless absolute_result is set to False, in which
+ case it returns a tuple containing the deepest object found along the path, and the
+ remainder of the path after that object as a string (or None if there is no remaining
+ path). Raises a DoesNotExist exception if no object is found with the given path.
+
+ If the path you're searching for is known to exist, it is always faster to use
+ absolute_result=True - unless the path depth is over ~40, in which case the high cost
+ of the absolute query makes a binary search (i.e. non-absolute) faster.
"""
- slugs = path.split(pathsep)
- obj = root
- remaining_slugs = list(slugs)
- remainder = None
- for slug in slugs:
- remaining_slugs.remove(slug)
- if slug: # ignore blank slugs, handles for multiple consecutive pathseps
+ # Note: SQLite allows max of 64 tables in one join. That means the binary search will
+ # only work on paths with a max depth of 127 and the absolute fetch will only work
+ # to a max depth of (surprise!) 63. Although this could be handled, chances are your
+ # tree structure won't be that deep.
+ segments = path.split(pathsep)
+
+ # Clean out blank segments. Handles multiple consecutive pathseps.
+ while True:
+ try:
+ segments.remove('')
+ except ValueError:
+ break
+
+ # Special-case a lack of segments. No queries necessary.
+ if not segments:
+ if root is not None:
+ if absolute_result:
+ return root
+ return root, None
+ else:
+ raise self.model.DoesNotExist('%s matching query does not exist.' % self.model._meta.object_name)
+
+ def make_query_kwargs(segments, root):
+ kwargs = {}
+ prefix = ""
+ revsegs = list(segments)
+ revsegs.reverse()
+
+ for segment in revsegs:
+ kwargs["%s%s__exact" % (prefix, field)] = segment
+ prefix += "parent__"
+
+ if prefix:
+ kwargs[prefix[:-2]] = root
+
+ return kwargs
+
+ def find_obj(segments, depth, deepest_found=None):
+ if deepest_found is None:
+ deepest_level = 0
+ elif root is None:
+ deepest_level = deepest_found.get_level() + 1
+ else:
+ deepest_level = deepest_found.get_level() - root.get_level()
+ try:
+ obj = self.get(**make_query_kwargs(segments[deepest_level:depth], deepest_found or root))
+ except self.model.DoesNotExist:
+ if not deepest_level and depth > 1:
+ # make sure there's a root node...
+ depth = 1
+ else:
+ # Try finding one with half the path since the deepest find.
+ depth = (deepest_level + depth)/2
+
+ if deepest_level == depth:
+ # This should happen if nothing is found with any part of the given path.
+ if root is not None and deepest_found is None:
+ return root, pathsep.join(segments)
+ raise
+
+ return find_obj(segments, depth, deepest_found)
+ else:
+ # Yay! Found one!
+ if root is None:
+ deepest_level = obj.get_level() + 1
+ else:
+ deepest_level = obj.get_level() - root.get_level()
+
+ # Could there be a deeper one?
+ if obj.is_leaf_node():
+ return obj, pathsep.join(segments[deepest_level:]) or None
+
+ depth += (len(segments) - depth)/2 or len(segments) - depth
+
+ if depth > deepest_level + obj.get_descendant_count():
+ depth = deepest_level + obj.get_descendant_count()
+
+ if deepest_level == depth:
+ return obj, pathsep.join(segments[deepest_level:]) or None
+
try:
- obj = self.get(slug__exact=slug, parent__exact=obj)
+ return find_obj(segments, depth, obj)
except self.model.DoesNotExist:
- if absolute_result:
- obj = None
- remaining_slugs.insert(0, slug)
- remainder = pathsep.join(remaining_slugs)
- break
- if obj:
- if absolute_result:
- return obj
- else:
- return (obj, remainder)
- raise self.model.DoesNotExist('%s matching query does not exist.' % self.model._meta.object_name)
+ # Then this was the deepest.
+ return obj, pathsep.join(segments[deepest_level:])
+
+ if absolute_result:
+ return self.get(**make_query_kwargs(segments, root))
+
+ # Try a modified binary search algorithm. Feed the root in so that query complexity
+ # can be reduced. It might be possible to weight the search towards the beginning
+ # of the path, since short paths are more likely, but how far forward? It would
+ # need to shift depending on len(segments) - perhaps logarithmically?
+ return find_obj(segments, len(segments)/2 or len(segments))
-class TreeModel(models.Model):
+class TreeModel(MPTTModel):
objects = TreeManager()
parent = models.ForeignKey('self', related_name='children', null=True, blank=True)
- slug = models.SlugField()
-
- def get_path(self, pathsep='/', field='slug'):
- path = getattr(self, field, '?')
- parent = self.parent
- while parent:
- path = getattr(parent, field, '?') + pathsep + path
- parent = parent.parent
- return path
+ slug = models.SlugField(max_length=255)
+
+ def get_path(self, root=None, pathsep='/', field='slug'):
+ if root == self:
+ return ''
+
+ if root is not None and not self.is_descendant_of(root):
+ raise AncestorDoesNotExist(root)
+
+ 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):
abstract = True
-class TreeEntity(TreeModel, Entity):
+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 TreeEntity(Entity, TreeModel):
+ __metaclass__ = TreeEntityBase
+
@property
def attributes(self):
if self.parent:
- return QuerySetMapper(self.attribute_set, passthrough=self.parent.attributes)
+ return QuerySetMapper(self.attribute_set.all(), passthrough=self.parent.attributes)
return super(TreeEntity, self).attributes
- @property
- def relationships(self):
- if self.parent:
- return QuerySetMapper(self.relationship_set, passthrough=self.parent.relationships)
- return super(TreeEntity, self).relationships
-
class Meta:
abstract = True
\ No newline at end of file