django1/django/db/models/related.py

143 lines
5.9 KiB
Python
Raw Normal View History

class BoundRelatedObject(object):
def __init__(self, related_object, field_mapping, original):
self.relation = related_object
self.field_mappings = field_mapping[related_object.name]
def template_name(self):
raise NotImplementedError
def __repr__(self):
return repr(self.__dict__)
class RelatedObject(object):
def __init__(self, parent_model, model, field):
self.parent_model = parent_model
self.model = model
self.opts = model._meta
self.field = field
self.edit_inline = field.rel.edit_inline
self.name = '%s:%s' % (self.opts.app_label, self.opts.module_name)
self.var_name = self.opts.object_name.lower()
def flatten_data(self, follow, obj=None):
new_data = {}
rel_instances = self.get_list(obj)
for i, rel_instance in enumerate(rel_instances):
instance_data = {}
for f in self.opts.fields + self.opts.many_to_many:
# TODO: Fix for recursive manipulators.
fol = follow.get(f.name, None)
if fol:
field_data = f.flatten_data(fol, rel_instance)
for name, value in field_data.items():
instance_data['%s.%d.%s' % (self.var_name, i, name)] = value
new_data.update(instance_data)
return new_data
def extract_data(self, data):
"""
Pull out the data meant for inline objects of this class,
i.e. anything starting with our module name.
"""
return data # TODO
def get_list(self, parent_instance=None):
"Get the list of this type of object from an instance of the parent class."
if parent_instance is not None:
attr = getattr(parent_instance, self.get_accessor_name())
if self.field.rel.multiple:
# For many-to-many relationships, return a list of objects
# corresponding to the xxx_num_in_admin options of the field
objects = list(attr.all())
count = len(objects) + self.field.rel.num_extra_on_change
if self.field.rel.min_num_in_admin:
count = max(count, self.field.rel.min_num_in_admin)
if self.field.rel.max_num_in_admin:
count = min(count, self.field.rel.max_num_in_admin)
change = count - len(objects)
if change > 0:
return objects + [None] * change
if change < 0:
return objects[:change]
else: # Just right
return objects
else:
# A one-to-one relationship, so just return the single related
# object
return [attr]
else:
if self.field.rel.min_num_in_admin:
return [None] * max(self.field.rel.num_in_admin, self.field.rel.min_num_in_admin)
else:
return [None] * self.field.rel.num_in_admin
def get_db_prep_lookup(self, lookup_type, value):
# Defer to the actual field definition for db prep
return self.field.get_db_prep_lookup(lookup_type, value)
def editable_fields(self):
"Get the fields in this class that should be edited inline."
return [f for f in self.opts.fields + self.opts.many_to_many if f.editable and f != self.field]
def get_follow(self, override=None):
if isinstance(override, bool):
if override:
over = {}
else:
return None
else:
if override:
over = override.copy()
elif self.edit_inline:
over = {}
else:
return None
over[self.field.name] = False
return self.opts.get_follow(over)
def get_manipulator_fields(self, opts, manipulator, change, follow):
if self.field.rel.multiple:
if change:
attr = getattr(manipulator.original_object, self.get_accessor_name())
count = attr.count()
count += self.field.rel.num_extra_on_change
else:
count = self.field.rel.num_in_admin
if self.field.rel.min_num_in_admin:
count = max(count, self.field.rel.min_num_in_admin)
if self.field.rel.max_num_in_admin:
count = min(count, self.field.rel.max_num_in_admin)
else:
count = 1
fields = []
for i in range(count):
for f in self.opts.fields + self.opts.many_to_many:
if follow.get(f.name, False):
prefix = '%s.%d.' % (self.var_name, i)
fields.extend(f.get_manipulator_fields(self.opts, manipulator, change,
name_prefix=prefix, rel=True))
return fields
def __repr__(self):
return "<RelatedObject: %s related to %s>" % (self.name, self.field.name)
def bind(self, field_mapping, original, bound_related_object_class=BoundRelatedObject):
return bound_related_object_class(self, field_mapping, original)
def get_accessor_name(self):
# This method encapsulates the logic that decides what name to give an
# accessor descriptor that retrieves related many-to-one or
# many-to-many objects. It uses the lower-cased object_name + "_set",
# but this can be overridden with the "related_name" option.
if self.field.rel.multiple:
# If this is a symmetrical m2m relation on self, there is no reverse accessor.
if getattr(self.field.rel, 'symmetrical', False) and self.model == self.parent_model:
return None
return self.field.rel.related_name or (self.opts.object_name.lower() + '_set')
else:
return self.field.rel.related_name or (self.opts.object_name.lower())