def get_verbose_name(model_or_queryset, field_path):
if isinstance(model_or_queryset, Manager):
model = model_or_queryset.model
elif isinstance(model_or_queryset, QuerySet):
model = model_or_queryset.model
elif isinstance(model_or_queryset, Model):
model = model_or_queryset
else:
raise AttributeError("`get_verbose_name` expects Manager, Queryset or Model as first parameter")
if isinstance(field_path, basestring):
field = get_field_by_path(model, field_path)
elif isinstance(field_path, models.Field):
field = field_path
return field.verbose_name
def merge(master, other, fields=None, commit=False, m2m=None, related=None): # noqa
"""
Merge 'other' into master.
`fields` is a list of fieldnames that must be readed from ``other`` to put into master.
If ``fields`` is None ``master`` will get all the ``other`` values except primary_key.
Finally ``other`` will be deleted and master will be preserved
@param master: Model instance
@param other: Model instance
@param fields: list of fieldnames to merge
@param m2m: list of m2m fields to merge. If empty will be removed
@param related: list of related fieldnames to merge. If empty will be removed
@return:
"""
fields = fields or [f.name for f in master._meta.fields]
all_m2m = {}
all_related = {}
if related == ALL_FIELDS:
related = [rel.get_accessor_name()
for rel in compat.get_all_related_objects(master)]
# for rel in master._meta.get_all_related_objects(False, False, False)]
if m2m == ALL_FIELDS:
m2m = [field.name for field in master._meta.many_to_many]
if m2m and not commit:
raise ValueError('Cannot save related with `commit=False`')
with compat.atomic():
result = clone_instance(master)
for fieldname in fields:
f = get_field_by_path(master, fieldname)
if f and not f.primary_key:
setattr(result, fieldname, getattr(other, fieldname))
if m2m:
for fieldname in set(m2m):
all_m2m[fieldname] = []
field_object = get_field_by_path(master, fieldname)
if not isinstance(field_object, ManyToManyField):
raise ValueError('{0} is not a ManyToManyField field'.format(fieldname))
source_m2m = getattr(other, field_object.name)
for r in source_m2m.all():
all_m2m[fieldname].append(r)
if related:
for name in set(related):
related_object = get_field_by_path(master, name)
all_related[name] = []
if related_object and isinstance(related_object.field, OneToOneField):
try:
accessor = getattr(other, name)
all_related[name] = [(related_object.field.name, accessor)]
except ObjectDoesNotExist:
pass
else:
accessor = getattr(other, name, None)
if accessor:
rel_fieldname = list(accessor.core_filters.keys())[0].split('__')[0]
for r in accessor.all():
all_related[name].append((rel_fieldname, r))
if commit:
for name, elements in list(all_related.items()):
for rel_fieldname, element in elements:
setattr(element, rel_fieldname, master)
element.save()
other.delete()
result.save()
for fieldname, elements in list(all_m2m.items()):
dest_m2m = getattr(result, fieldname)
for element in elements:
dest_m2m.add(element)
return result
