def m2m_changed_handler(sender, *args, **kwargs):
"""
A model's save() never gets called on ManyToManyField changes, m2m_changed-signal is sent.
sender = dynamically generated model in m2m-table
instance = parent
related_instance = instance being m2m'ed
"""
action = kwargs['action']
instance = kwargs['instance']
logger.debug("m2m_changed: %s (%s) {%s}"%(sender, args, kwargs))
bulk = []
if is_df(instance) and (action in ['post_add', 'post_remove']):
pk_set = list(kwargs.get('pk_set') or [])
relation_name = sender._meta.db_table.replace(sender._meta.app_label + '_' + instance.__class__.__name__.lower() + '_', '')
relations = {k.name:k for k in m2m_relations(instance)}
field = relations[relation_name]
for pk in pk_set:
related_instance = get_relation(relations[relation_name]).objects.get(pk=pk)
changes = {field.name: {'changed': [pk],
'changed_to_string': six.text_type(related_instance)}}
# reflect change
bulk.append(History.objects.add(
action=action,
changes=changes,
model=instance,
commit=False,))
# m2m to reflect on changes
field = get_field(field)
changes = {field.name: {'changed': [instance.pk],
'changed_to_string': six.text_type(instance),
'm2mpg': True,}}
bulk.append(History.objects.add(
action='add' if action in ['post_add'] else 'rem',
changes=changes,
model=related_instance,
commit=False,))
if is_df(instance) and (action in ['pre_clear']):
# "For the pre_clear and post_clear actions, this is None."
# TODO: should defer this until post_clear is done to be sure it happened
# TODO: background job, optional execution
relations = instance._meta.get_all_related_many_to_many_objects()
for relation in relations:
instances = get_m2m_reverse_instances(instance, relation)
field = get_model_relation_by_instance(kwargs['model'], instance)
changes = {field.name: {'changed': [instance.pk],
'changed_to_string': six.text_type(instance)}}
for k in instances:
bulk.append(History.objects.add(
action=action,
changes=changes,
model=k,
commit=False,))
if bulk:
History.objects.bulk_create(bulk)
def handle_m2m(sender, *args, **kwargs):
"""
A model's save() never gets called on ManyToManyField changes, m2m_changed-signal is sent.
sender = dynamically generated model in m2m-table
instance = parent
related_instance = instance being m2m'ed
"""
action = kwargs['action']
instance = kwargs['instance']
if hasattr(instance, 'get_changes') and (action == 'post_add' or action == 'post_remove'):
pk_set = list(kwargs['pk_set'])
relation_name = sender._meta.db_table.replace(sender._meta.app_label + '_' + instance.__class__.__name__.lower() + '_', '')
for pk in pk_set:
relations = {k.name:k for k in instance.get_m2m_relations()}
related_instance = get_relation(relations[relation_name]).objects.get(pk=pk)
field = relations[relation_name]
changes = {field.name: {'changed': [pk], 'changed_to_string': six.text_type(related_instance)}}
# TODO: add meta information about relation
# - parent, child
History.objects.add(
action=ACTION_MAP[action],
changes=changes,
model=instance,)
def add(self, action, changes, model, user=None, object_id=None):
if not getattr(settings, 'DJANGO_HISTORY_TRACK', True):
return
request = get_current_request()
if not user:
if request:
user = request.user
user_id = user.pk if user else None
model_ct = ContentType.objects.get_for_model(model)
model_id = model_ct.pk
object_id = object_id or model.pk
# exclusion / none -checks
excludes = get_setting('EXCLUDE_CHANGES')
if excludes:
excludes_for_model = excludes.get("{0}.{1}".format(model_ct.app_label, model_ct.model))
if excludes_for_model:
for k,v in six.iteritems(copy.deepcopy(changes)):
if k in excludes_for_model.get('fields', []):
del changes[k]
if not changes:
return
# for FKs, get old/new information
fields = model._meta.local_fields
def get_item(model, pk):
value = None
if isinstance(pk, models.Model):
pk = copy.deepcopy(pk.pk)
try:
value = six.text_type(model.objects.get(pk=pk))
except Exception as e:
if settings.DEBUG: print(e)
return value
def match_field(model, changed_field):
try:
field = model._meta.get_field(k)
except:
field = model._meta.get_field(k.replace('_id', ''))
return field
for k,v in six.iteritems(changes):
field = match_field(model, k)
v['verbose_name'] = six.text_type(field.verbose_name)
if isinstance(field, models.ForeignKey):
parent_model = get_relation(field)
if v['new']:
v['new_to_string'] = get_item(parent_model, v['new'])
if isinstance(v['new'], models.Model):
v['new'] = v['new'].pk
if v['old']:
v['old_to_string'] = get_item(parent_model, v['old'])
if isinstance(v['old'], models.Model):
v['old'] = v['old'].pk
v['is_fk'] = True
if isinstance(field, models.ManyToManyField):
v['is_m2m'] = True
v['m2m_css_class'] = 'old_change'
if 'm2m.add' in action:
v['m2m_css_class'] = 'new_change'
if 'delete' in action:# M2M copied on delete
for field in model._meta.local_many_to_many:
pk_set = getattr(model, field.name).all()
row = {
'changed': list([k.pk for k in pk_set]),
'is_m2m': True,
'm2m_css_class': 'old_change',
'changed_to_string': u", ".join([six.text_type(k) for k in pk_set]),
'verbose_name': six.text_type(field.verbose_name),
}
changes[field.name] = row
changeset = {
'fields': changes,
'model': {
'to_string': six.text_type(model),
'verbose_name': six.text_type(model._meta.verbose_name),
'content_type': {
'id': model_ct.pk,
'app_label': model_ct.app_label,
'model': model_ct.model,
}
},
'user': {
'to_string': six.text_type(user),
}
}
history = self.model(
action=action,
changes=changeset,
model=model_id,
user=user_id,
object_id=object_id,)
history.save(force_insert=True)
def get_model_relation_by_instance(model, relation):
return [k for k in m2m_relations(model) if \
isinstance(relation, get_relation(k))].pop()
