CODEWITHSUNDEEP
djangodjango-modelsdjango-views
szaman
szaman

Reputation: 6756

Clone object with django

I have a model which can be described as:

Element: - element has one to one field with ElementData

ElementData: - it has ForeignKey to ElementImage - which describes default image

ElementImage: - it has ForeignKey to ElementData

ElementVideo: - it has foreignKey to ElementData

Now I want element and all subtables cloned. I tried to use snippet which I found here. I put this function to Element and ElementData and when I in element try to clone ElementData I have constraint violation. Can someone help me?

Upvotes: 1

Views: 1293

Answers (2)

szaman
szaman

Reputation: 6756

my solution:

def clone(self):
        old = self
        images = old.element_data.images.all()
        videos = old.element_data.videos.all()
        element_data = self.element_data
        element_data.id = None
        element_data.save()
        for image in images:
            image.id = None
            image.element_data = element_data
            image.save()
        for video in videos:
            video.id = None
            video.element_data = element_data
            video.save()

        new_kwargs = dict([(fld.name, getattr(old, fld.name)) for fld in old._meta.fields if fld.name != 'id']);
        new_kwargs['element_data'] = element_data
        return self.__class__.objects.create(**new_kwargs)

Please write what you think about it

Upvotes: 1

Ski
Ski

Reputation: 14487

Because Element has OneToOne relation to ElementData, you need to clone the ElementData before cloning Element. Like this:

class Element(...):
    def clone(self):
        new_kwargs = dict([(fld.name, getattr(old, fld.name)) for fld in old._meta.fields if fld.name != 'id']);
        new_data = self.data.clone()
        new_kwargs['data'] = new_data
        return self.__class__.objects.create(**new_kwargs)

Upvotes: 3

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