class EmbeddedDocumentForm(
with_metaclass(DocumentFormMetaclass, BaseDocumentForm)):
def __init__(self,
parent_document,
data=None,
files=None,
position=None,
*args,
**kwargs):
if self._meta.embedded_field is not None and \
self._meta.embedded_field not in parent_document._fields:
raise FieldError("Parent document must have field %s" %
self._meta.embedded_field)
instance = kwargs.pop('instance', None)
if isinstance(parent_document._fields.get(self._meta.embedded_field),
ListField):
# if we received a list position of the instance and no instance
# load the instance from the parent document and proceed as normal
if instance is None and position is not None:
instance = getattr(parent_document,
self._meta.embedded_field)[position]
# same as above only the other way around. Note: Mongoengine
# defines equality as having the same data, so if you have 2
# objects with the same data the first one will be edited. That
# may or may not be the right one.
if instance is not None and position is None:
emb_list = getattr(parent_document, self._meta.embedded_field)
position = next(
(i for i, obj in enumerate(emb_list) if obj == instance),
None)
super(EmbeddedDocumentForm, self).__init__(data=data,
files=files,
instance=instance,
*args,
**kwargs)
self.parent_document = parent_document
self.position = position
def save(self, commit=True):
"""If commit is True the embedded document is added to the parent
document. Otherwise the parent_document is left untouched and the
embedded is returned as usual.
"""
if self.errors:
raise ValueError("The %s could not be saved because the data"
"didn't validate." %
self.instance.__class__.__name__)
if commit:
field = self.parent_document._fields.get(self._meta.embedded_field)
if isinstance(field, ListField) and self.position is None:
# no position given, simply appending to ListField
try:
self.parent_document.update(
**
{"push__" + self._meta.embedded_field: self.instance})
except:
raise OperationError("The %s could not be appended." %
self.instance.__class__.__name__)
elif isinstance(field, ListField) and self.position is not None:
# updating ListField at given position
try:
self.parent_document.update(
**{
"__".join(("set", self._meta.embedded_field,
str(self.position))):
self.instance
})
except:
raise OperationError(
"The %s could not be updated at "
"position %d." %
(self.instance.__class__.__name__, self.position))
else:
# not a listfield on parent, treat as an embedded field
setattr(self.parent_document, self._meta.embedded_field,
self.instance)
self.parent_document.save()
return self.instance
class DocumentForm(with_metaclass(DocumentFormMetaclass, BaseDocumentForm)):
pass