Merge branch 'master' of git://github.com/melinath/philo

[philo.git] / models / base.py

diff --git a/models/base.py b/models/base.py
index 2f5bf93..c7b1c26 100644 (file)
--- a/models/base.py
+++ b/models/base.py
@@ -1,15 +1,21 @@
+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 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 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 UserDict import DictMixin

+from mptt.models import MPTTModel, MPTTModelBase, MPTTOptions

 
 
 class Tag(models.Model):
 
 
 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
        
        def __unicode__(self):
                return self.name


@@ -29,57 +35,157 @@ class Titled(models.Model):
                abstract = True
 
 
                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)
+
+
+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)
+       @property
+       def attribute(self):
+               return self.attribute_set.all()[0]

        
        

-       def delete_value(self):
-               self.json_value = json.dumps(None)
+       def apply_data(self, data):
+               raise NotImplementedError

        
        

-       value = property(get_value, set_value, delete_value)
+       def value_formfield(self, **kwargs):
+               raise NotImplementedError

        
        def __unicode__(self):
        
        def __unicode__(self):

-               return u'"%s": %s' % (self.key, self.value)
+               return unicode(self.value)

        
        class Meta:
        
        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.')
+       
+       def __unicode__(self):
+               return self.value_json
+       
+       def value_formfield(self, **kwargs):
+               kwargs['initial'] = self.value_json
+               return self._meta.get_field('value').formfield(**kwargs)
+       
+       def apply_data(self, cleaned_data):
+               self.value = cleaned_data.get('value', None)
+       
+       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)
+       value = generic.GenericForeignKey()
+       
+       def value_formfield(self, form_class=forms.ModelChoiceField, **kwargs):
+               if self.content_type is None:
+                       return None
+               kwargs.update({'initial': self.object_id, 'required': False})
+               return form_class(self.content_type.model_class()._default_manager.all(), **kwargs)
+       
+       def apply_data(self, cleaned_data):
+               if 'value' in cleaned_data and cleaned_data['value'] is not None:
+                       self.value = cleaned_data['value']
+               else:
+                       self.content_type = cleaned_data.get('content_type', None)
+                       # If there is no value set in the cleaned data, clear the stored value.
+                       self.object_id = None
+       
+       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_id_list(self):
+               if not self.values.count():
+                       return []
+               else:
+                       return self.values.values_list('object_id', flat=True)
+       
+       def get_value(self):
+               if self.content_type is None:
+                       return None
+               
+               return self.content_type.model_class()._default_manager.filter(id__in=self.get_object_id_list())
+       
+       def set_value(self, value):
+               # Value is probably a queryset - but allow any iterable.
+               
+               # These lines shouldn't be necessary; however, if value is an EmptyQuerySet,
+               # the code (specifically the object_id__in query) won't work without them. Unclear why...
+               if not value:
+                       value = []
+               
+               # Before we can fiddle with the many-to-many to foreignkeyvalues, we need
+               # a pk.
+               if self.pk is None:
+                       self.save()
+               
+               if isinstance(value, models.query.QuerySet):
+                       value = value.values_list('id', flat=True)
+               
+               self.values.filter(~models.Q(object_id__in=value)).delete()
+               current = self.get_object_id_list()
+               
+               for v in value:
+                       if v in current:
+                               continue
+                       self.values.create(content_type=self.content_type, object_id=v)
+       
+       value = property(get_value, set_value)
+       
+       def value_formfield(self, form_class=forms.ModelMultipleChoiceField, **kwargs):
+               if self.content_type is None:
+                       return None
+               kwargs.update({'initial': self.get_object_id_list(), 'required': False})
+               return form_class(self.content_type.model_class()._default_manager.all(), **kwargs)
+       
+       def apply_data(self, cleaned_data):
+               if 'value' in cleaned_data and cleaned_data['value'] is not None:
+                       self.value = cleaned_data['value']
+               else:
+                       self.content_type = cleaned_data.get('content_type', None)
+                       # If there is no value set in the cleaned data, clear the stored value.
+                       self.value = []
+       
+       class Meta:
+               app_label = 'philo'
+

 
 

-class Relationship(models.Model):
-       entity_content_type = models.ForeignKey(ContentType, related_name='relationship_entity_set', verbose_name='Entity type')
+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')
        entity = generic.GenericForeignKey('entity_content_type', 'entity_object_id')
        entity_object_id = models.PositiveIntegerField(verbose_name='Entity ID')
        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)

        value = generic.GenericForeignKey('value_content_type', 'value_object_id')
        
        value = generic.GenericForeignKey('value_content_type', 'value_object_id')
        

+       key = models.CharField(max_length=255)
+       

        def __unicode__(self):
                return u'"%s": %s' % (self.key, self.value)
        
        class Meta:
                app_label = 'philo'
        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):
 
 
 class QuerySetMapper(object, DictMixin):


@@ -89,11 +195,15 @@ class QuerySetMapper(object, DictMixin):
        
        def __getitem__(self, key):
                try:
        
        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
                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())
        
        def keys(self):
                keys = set(self.queryset.values_list('key', flat=True).distinct())


@@ -102,17 +212,66 @@ class QuerySetMapper(object, DictMixin):
                return list(keys)
 
 
                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):
+               new = super(EntityBase, cls).__new__(cls, name, bases, attrs)
+               entity_options = attrs.pop('EntityMeta', None)
+               setattr(new, '_entity_meta', EntityOptions(entity_options))
+               entity_class_prepared.send(sender=new)
+               return new
+
+

 class Entity(models.Model):
 class Entity(models.Model):

+       __metaclass__ = EntityBase
+       

        attribute_set = generic.GenericRelation(Attribute, content_type_field='entity_content_type', object_id_field='entity_object_id')
        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):
        
        @property
        def attributes(self):

-               return QuerySetMapper(self.attribute_set)
+               return QuerySetMapper(self.attribute_set.all())
+       
+       @property
+       def _added_attribute_registry(self):
+               if not hasattr(self, '_real_added_attribute_registry'):
+                       self._real_added_attribute_registry = {}
+               return self._real_added_attribute_registry

        
        @property
        
        @property

-       def relationships(self):
-               return QuerySetMapper(self.relationship_set)
+       def _removed_attribute_registry(self):
+               if not hasattr(self, '_real_removed_attribute_registry'):
+                       self._real_removed_attribute_registry = []
+               return self._real_removed_attribute_registry
+       
+       def save(self, *args, **kwargs):
+               super(Entity, self).save(*args, **kwargs)
+               
+               for key in self._removed_attribute_registry:
+                       self.attribute_set.filter(key__exact=key).delete()
+               del self._removed_attribute_registry[:]
+               
+               for field, value in self._added_attribute_registry.items():
+                       try:
+                               attribute = self.attribute_set.get(key__exact=field.key)
+                       except Attribute.DoesNotExist:
+                               attribute = Attribute()
+                               attribute.entity = self
+                               attribute.key = field.key
+                       
+                       field.set_attribute_value(attribute, value)
+                       attribute.save()
+               self._added_attribute_registry.clear()

        
        class Meta:
                abstract = True
        
        class Meta:
                abstract = True


@@ -121,51 +280,142 @@ class Entity(models.Model):
 class TreeManager(models.Manager):
        use_for_related_fields = 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)
+               
+               # Check for a trailing pathsep so we can restore it later.
+               trailing_pathsep = False
+               if segments[-1] == '':
+                       trailing_pathsep = True
+               
+               # 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 build_path(segments):
+                       path = pathsep.join(segments)
+                       if trailing_pathsep and segments and segments[-1] != '':
+                               path += pathsep
+                       return path
+               
+               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, build_path(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, build_path(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, build_path(segments[deepest_level:]) or None
+                               

                                try:
                                try:

-                                       obj = self.get(slug__exact=slug, parent__exact=obj)
+                                       return find_obj(segments, depth, obj)

                                except self.model.DoesNotExist:
                                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, build_path(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)
        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()
+               
+               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 list(qs) + [self]])

        path = property(get_path)
        
        def __unicode__(self):
        path = property(get_path)
        
        def __unicode__(self):


@@ -176,18 +426,22 @@ class TreeModel(models.Model):
                abstract = True
 
 
                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:
        @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
        
                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
        class Meta:
                abstract = True
\ No newline at end of file