Yes, it is the same thing. What I wonder is if there is a standard or better way of getting the same functionality as my full_save method?
Regards David 2011/8/19 Yaşar Arabacı <[email protected]> > I don't quite understand what you did there, but, it seems to me it is the > same thing with your initial post. > > ref = getattr(self, f.name) -> you are getting a field here, this field is > a empty descriptor, doesn't hold any data yet. > ref.full_save(*args,*kwargs) -> you populated your field with data here by > calling full_save on it > setattr(self,f.name,ref) -> you are assigning this field to be a part of > parent object, where you got it initially > > then you are saving the parent object. > > > > > > 2011/8/19 David Jacquet <[email protected]> > >> >> Thanks Yaşar and Jani for your fast replies! >> >> >> I understand that normally one would assign in the reverse order. However >> I do not understand exactly what happens when I do >> meeting.place = meeting.place >> never in my programming experience have I seen an example when >> x=x >> really does something. Isn't this strange? >> >> >> Anyway, the reason for me wanting to go around normal behavior is that I >> have a quite complicated and nested datamodel. Then I offer an api where >> people can post JSON object. The will posts will be heavily nested ojbects >> and I do not want save it to db by rewriting the whole save-chain in my >> code. I have solved this by creating the class AREM below. When I have a >> dictionary d representing a class A (subclass to AREM) and I want it saved I >> do: >> >> a = A().from_dict(d) >> a.full_save() >> >> I have gotten it to work, but not before I added the (for me very strange) >> row >> >> setattr(self, f.name, ref) #Without this everything collapses >> >> residing on the second most bottom row in the code below. The problem is >> that I do not know what it does, nor if there is a more elegant, faster or >> better way to do it. >> >> Best Regards >> David >> >> >> >> #class AbstractRecursiveEnabledModel(models.Model): >> class AREM(AMCS): >> class Meta: >> abstract = True >> >> def from_dict(self, d): >> if not isinstance(d, dict): >> return d >> fl = self._meta.fields >> for f in fl: >> if d.has_key(f.name) and f.rel and d[f.name] is not None: >> d[f.name] = f.rel.to().from_dict(d[f.name]) >> self.__init__(**d) >> return self >> >> def full_save(self,*args, **kwargs): fl = self._meta.fields >> >> for f in fl: >> if f.rel: >> ref = getattr(self, f.name) >> if ref is not None and ref.pk is None and ref is not >> self: >> ref.full_save(*args, **kwargs) >> setattr(self, f.name, ref) #Without this everything >> collapses >> super(AREM, self).save(*args, **kwargs) >> >> >> >> >> >> >> >> On Fri, Aug 19, 2011 at 2:34 PM, Jani Tiainen <[email protected]> wrote: >> >>> On 08/19/2011 03:15 PM, Jacco wrote: >>> >>>> I am having great difficulties in saving nested models in an easy >>>> way. >>>> >>>> >>>> #Two (almost) identical functions: >>>> def test1(): >>>> place = Place(where='Paris') >>>> >>> >>> place is not saved, thus it does not have a primary key (id) >>> >>> >>> meeting = Meeting(place=place, when='2011-01-01') >>>> >>> >>> You assign non saved instance to a meeting. Probably what happened >>> internally is that place.pk is copied to meeting.place_id. >>> >>> place.save() >>>> >>> >>> You saved place. Changes in model are not reflected to referred model. >>> >>> meeting.save() >>>> >>> >>> You save meeting with still (partially) stale place pk. thus resulting an >>> exception. >>> >>> >>> def test2(): >>>> place = Place(where='Paris') >>>> meeting = Meeting(place=place, when='2011-01-01') >>>> >>>> place.save() >>>> meeting.place = meeting.place #BY setting meeting.place to >>>> itself, it works !!!!!!!!!!!! >>>> >>> >>> You updated your meeting internal structure. >>> >>> meeting.save() >>>> return meeting >>>> >>>> ---------------------------------------------------------------------------------------------------------------------------------------------- >>>> >>>> >>>> >>>> - Running test1() results in crash "null value in column "place_id" >>>> violates not-null constraint" >>>> - Running test2() results in OK. >>>> - Only difference is the dummy line "meting.place = meeting.place". >>>> >>>> Could someone who really understands this explain what is going on? >>>> >>>> >>> What's going on that you have done it incorrect order. >>> >>> place = Place(where='Paris') >>> place.save() # Place saved, PK assigned. >>> >>> >>> meeting = Meeting(place=place, when='2011-01-01') >>> meeting.save() # Meeting saved with correct place. >>> >>> -- >>> >>> Jani Tiainen >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Django users" group. >>> To post to this group, send email to [email protected]. >>> To unsubscribe from this group, send email to >>> [email protected]. >>> For more options, visit this group at >>> http://groups.google.com/group/django-users?hl=en. >>> >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "Django users" group. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> For more options, visit this group at >> http://groups.google.com/group/django-users?hl=en. >> > > -- > You received this message because you are subscribed to the Google Groups > "Django users" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/django-users?hl=en. > -- You received this message because you are subscribed to the Google Groups "Django users" group. 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