def evolution(self):
"Generate an evolution that would neutralize the diff"
mutations = {}
for app_label, app_changes in self.changed.items():
for model_name, change in app_changes.get('changed', {}).items():
for field_name in change.get('added',{}):
field_sig = self.current_sig[app_label][model_name]['fields'][field_name]
add_params = [(key,field_sig[key])
for key in field_sig.keys()
if key in ATTRIBUTE_DEFAULTS.keys()]
add_params.append(('field_type', field_sig['field_type']))
if (field_sig['field_type'] != models.ManyToManyField and
not field_sig.get('null', ATTRIBUTE_DEFAULTS['null'])):
add_params.append(
('initial',
get_initial_value(app_label, model_name,
field_name)))
if 'related_model' in field_sig:
add_params.append(('related_model',
'%s' % field_sig['related_model']))
mutations.setdefault(app_label,[]).append(
AddField(model_name, field_name, **dict(add_params)))
for field_name in change.get('deleted',[]):
mutations.setdefault(app_label,[]).append(
DeleteField(model_name, field_name))
for field_name,field_change in change.get('changed',{}).items():
changed_attrs = {}
current_field_sig = self.current_sig[app_label][model_name]['fields'][field_name]
for prop in field_change:
if prop == 'related_model':
changed_attrs[prop] = current_field_sig[prop]
else:
changed_attrs[prop] = \
current_field_sig.get(prop,
ATTRIBUTE_DEFAULTS[prop])
if (changed_attrs.has_key('null') and
current_field_sig['field_type'] !=
models.ManyToManyField and
not current_field_sig.get('null',
ATTRIBUTE_DEFAULTS['null'])):
changed_attrs['initial'] = \
get_initial_value(app_label, model_name, field_name)
mutations.setdefault(app_label,[]).append(
ChangeField(model_name, field_name,current_field_sig, **changed_attrs)) #j----------add
for model_name in app_changes.get('deleted',{}):
mutations.setdefault(app_label,[]).append(
DeleteModel(model_name))
return mutations
def __init__(self, original, current):
self.original_sig = original
self.current_sig = current
self.changed = {}
self.deleted = {}
if self.original_sig.get('__version__', 1) != 1:
raise EvolutionException(
"Unknown version identifier in original signature: %s",
self.original_sig['__version__'])
if self.current_sig.get('__version__', 1) != 1:
raise EvolutionException(
"Unknown version identifier in target signature: %s",
self.current_sig['__version__'])
for app_name, old_app_sig in original.items():
if app_name == '__version__':
# Ignore the __version__ tag
continue
new_app_sig = self.current_sig.get(app_name, None)
if new_app_sig is None:
# App has been deleted
self.deleted[app_name] = old_app_sig.keys()
continue
for model_name, old_model_sig in old_app_sig.items():
new_model_sig = new_app_sig.get(model_name, None)
if new_model_sig is None:
# Model has been deleted
self.changed.setdefault(app_name,
{}).setdefault('deleted',
[]).append(model_name)
continue
old_fields = old_model_sig['fields']
new_fields = new_model_sig['fields']
# Look for deleted or modified fields
for field_name, old_field_data in old_fields.items():
new_field_data = new_fields.get(field_name, None)
if new_field_data is None:
# Field has been deleted
self.changed.setdefault(app_name,
{}).setdefault('changed',
{}).setdefault(model_name,
{}).setdefault('deleted',
[]).append(field_name)
continue
properties = set(old_field_data.keys())
properties.update(new_field_data.keys())
for prop in properties:
old_value = old_field_data.get(prop,
ATTRIBUTE_DEFAULTS.get(prop, None))
new_value = new_field_data.get(prop,
ATTRIBUTE_DEFAULTS.get(prop, None))
if old_value != new_value:
try:
if (prop == 'field_type' and
(old_value().get_internal_type() ==
new_value().get_internal_type())):
continue
except TypeError:
pass
# Field has been changed
self.changed.setdefault(app_name,
{}).setdefault('changed',
{}).setdefault(model_name,
{}).setdefault('changed',
{}).setdefault(field_name,[]).append(prop)
# Look for added fields
new_fields = new_model_sig['fields']
for field_name, new_field_data in new_fields.items():
old_field_data = old_fields.get(field_name, None)
if old_field_data is None:
self.changed.setdefault(app_name,
{}).setdefault('changed',
{}).setdefault(model_name,
{}).setdefault('added',
[]).append(field_name)
