def VocabModel(cls, table_type='row', table=None):
if table_type not in ('row', 'col', 'instance'):
raise ValueError('table_type must be either "row", "col" or '
'"instance".')
attr = '_vocab_model_%s' % table_type
if not hasattr(cls, attr):
class Meta:
database = cls._meta.database
table_name = table or cls._meta.table_name + '_v'
extension_module = fn.fts5vocab(
cls._meta.entity,
SQL(table_type))
attrs = {
'term': VirtualField(TextField),
'doc': IntegerField(),
'cnt': IntegerField(),
'rowid': RowIDField(),
'Meta': Meta,
}
if table_type == 'col':
attrs['col'] = VirtualField(TextField)
elif table_type == 'instance':
attrs['offset'] = VirtualField(IntegerField)
class_name = '%sVocab' % cls.__name__
setattr(cls, attr, type(class_name, (VirtualModel,), attrs))
return getattr(cls, attr)
class BaseClosureTable(VirtualModel):
depth = VirtualField(IntegerField)
id = VirtualField(IntegerField)
idcolumn = VirtualField(TextField)
parentcolumn = VirtualField(TextField)
root = VirtualField(IntegerField)
tablename = VirtualField(TextField)
class Meta:
extension_module = 'transitive_closure'
@classmethod
def descendants(cls, node, depth=None, include_node=False):
query = (model_class
.select(model_class, cls.depth.alias('depth'))
.join(cls, on=(source_key == cls.id))
.where(cls.root == node)
.objects())
if depth is not None:
query = query.where(cls.depth == depth)
elif not include_node:
query = query.where(cls.depth > 0)
return query
@classmethod
def ancestors(cls, node, depth=None, include_node=False):
query = (model_class
.select(model_class, cls.depth.alias('depth'))
.join(cls, on=(source_key == cls.root))
.where(cls.id == node)
.objects())
if depth:
query = query.where(cls.depth == depth)
elif not include_node:
query = query.where(cls.depth > 0)
return query
@classmethod
def siblings(cls, node, include_node=False):
if referencing_class is model_class:
# self-join
fk_value = node.__data__.get(foreign_key.name)
query = model_class.select().where(foreign_key == fk_value)
else:
# siblings as given in reference_class
siblings = (referencing_class
.select(referencing_key)
.join(cls, on=(foreign_key == cls.root))
.where((cls.id == node) & (cls.depth == 1)))
# the according models
query = (model_class
.select()
.where(source_key << siblings)
.objects())
if not include_node:
query = query.where(source_key != node)
return query
