X-Git-Url: http://git.ithinksw.org/philo.git/blobdiff_plain/92691d27d00f2c9a1b0536020ca2a5c1ec07f3e3..ee5fbe5df5817578911fbf0c2e1fc2698e701b73:/models/base.py diff --git a/models/base.py b/models/base.py index 87914be..af1e880 100644 --- a/models/base.py +++ b/models/base.py @@ -1,21 +1,30 @@ +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): @@ -29,59 +38,199 @@ 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' - unique_together = ('key', 'entity_content_type', 'entity_object_id') + 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') + unique_together = (('key', 'entity_content_type', 'entity_object_id'), ('value_content_type', 'value_object_id')) class QuerySetMapper(object, DictMixin): @@ -91,11 +240,15 @@ 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()) @@ -104,17 +257,35 @@ class QuerySetMapper(object, DictMixin): 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 @@ -123,67 +294,131 @@ class Entity(models.Model): 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 has_ancestor(self, ancestor): - parent = self - while parent: - if parent == ancestor: - return True - parent = parent.parent - return False + slug = models.SlugField(max_length=255) def get_path(self, root=None, pathsep='/', field='slug'): - if root is not None and self.has_ancestor(root): - path = '' - parent = self - while parent and parent != root: - path = getattr(parent, field, '?') + pathsep + path - parent = parent.parent - return path - else: - path = getattr(self, field, '?') - parent = self.parent - while parent and parent != root: - path = getattr(parent, field, '?') + pathsep + path - parent = parent.parent - return path + 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): @@ -194,18 +429,22 @@ class TreeModel(models.Model): 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