def prepare(self):
"""This method is called when relation is ready to create it's
PrimaryTable"""
if self.foreign_class is None:
self.foreign_class = self.owner_class
self.owner_fk = camel2underscore(self.owner_class.__name__)
self.foreign_fk = camel2underscore(self.foreign_class.__name__)
if self.owner_fk == self.foreign_fk:
self.owner_fk = self.owner_fk + '1'
self.foreign_fk = self.foreign_fk + '2'
primary_table_clsname = (
self.owner_class.__name__ + self.foreign_class.__name__
)
primary_table_name = '{0}_{1}'.format(
self.owner_class.__table_name__, self.foreign_class.__table_name__
)
self.PrimaryTable = ObjectMeta(
primary_table_clsname, (ep.Object,), {
'__table_name__': primary_table_name,
self.owner_fk: ManyToOne(self.owner_class),
self.foreign_fk: ManyToOne(self.foreign_class),
'__pk__': (self.owner_fk + '_id', self.foreign_fk + '_id'),
}
)
class ManyToMany(Relation):
compat_types = [list, set]
columns = []
def __init__(
self, foreign_class = None, backref = None, fmt=LIST, **kwargs
):
self.prepared = False
self.foreign_class = foreign_class
self.backref = backref
self.fmt = fmt
super(ManyToMany, self).__init__(**kwargs)
def prepare(self):
"""This method is called when relation is ready to create it's
PrimaryTable"""
if self.foreign_class is None:
self.foreign_class = self.owner_class
self.owner_fk = camel2underscore(self.owner_class.__name__)
self.foreign_fk = camel2underscore(self.foreign_class.__name__)
if self.owner_fk == self.foreign_fk:
self.owner_fk = self.owner_fk + '1'
self.foreign_fk = self.foreign_fk + '2'
primary_table_clsname = (
self.owner_class.__name__ + self.foreign_class.__name__
)
primary_table_name = '{0}_{1}'.format(
self.owner_class.__table_name__, self.foreign_class.__table_name__
)
self.PrimaryTable = ObjectMeta(
primary_table_clsname, (ep.Object,), {
'__table_name__': primary_table_name,
self.owner_fk: ManyToOne(self.owner_class),
self.foreign_fk: ManyToOne(self.foreign_class),
'__pk__': (self.owner_fk + '_id', self.foreign_fk + '_id'),
}
)
def hydrate(self, inst, col_vals, dict_, session):
dict_[self.name] = LazyManyToMany(self, inst.session, inst.get_pk_value())
def _find_existing_primary(self, inst, obj):
try:
return self.PrimaryTable.get(
(getattr(self.PrimaryTable, self.owner_fk) == inst) &
(getattr(self.PrimaryTable, self.foreign_fk) == obj)
)
except NotFound:
return
def _resolve_diff(self, inst, prev, curr):
added, deleted = diff_unsorted(prev, curr) #@UnusedVariable
for obj in added:
if not self._find_existing_primary(inst, obj):
new_primary = self.PrimaryTable()
setattr(new_primary, self.owner_fk, inst)
setattr(new_primary, self.foreign_fk, obj)
inst.add(new_primary)
if inst.session is not None:
for obj in deleted:
to_delete = self._find_existing_primary(inst, obj)
if to_delete:
to_delete.delete()
def __get__(self, inst, cls):
if isinstance(inst._current[self.name], LazyManyToMany):
inst._current[self.name] = list(inst._current[self.name])
inst._current[self.name] = RelationList(
self, inst, inst._current[self.name]
)
return inst._current[self.name]
def __set__(self, inst, v):
prev = inst._current.get(self.name, [])
self._resolve_diff(inst, prev, v)
inst._current[self.name] = v
# def _is_compatible(self, value):
# return isinstance(value, (list, set))
def get_c_vals(self, dict_):
return {}
