Creating model (table) inheritance in Django 1.8 using PostgreSQL

[Some Developer]

I have a model which defines an item and many sub-models which inherit
from it to define the type of the model. Something like this:

Product(models.Model):
owner = models.ForeignKey(settings.AUTH_USER_MODEL)
name = models.CharField(max_length=255)

ProductItemText(Product):
type = models.TextField()

ProductItemBoolean(Product):
type = models.BooleanField()

etc etc. There are a lot more different sub-models for different types.

I'm a bit confused about how to generate a form based on the type that
the user wants to add to the database. Do you have to have a form each
individual sub-type or is there a nice workaround for this specific problem?

Any help is appreciated.

[Vijay Khemlani]

You could dynamically create a ModelForm based on the model class:

from django.forms import ModelForm

MetaClass = type('Meta', (), {'model': ProductItemText})

MetaModelForm = type('ProductModelForm', (ModelForm, ), {'Meta': MetaClass})

form = MetaModelForm()

The only thing you would need is the model class itself ("ProductItemText" in this particular case),  I think you could even add it as a classmethod to the base Product class.

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[Some Developer]

On 02/07/15 13:56, Vijay Khemlani wrote:
> You could dynamically create a ModelForm based on the model class:
>
> from django.forms import ModelForm
>
> MetaClass = type('Meta', (), {'model': ProductItemText})
>
> MetaModelForm = type('ProductModelForm', (ModelForm, ), {'Meta': MetaClass})
>
> form = MetaModelForm()
>
> The only thing you would need is the model class itself
> ("ProductItemText" in this particular case), I think you could even add
> it as a classmethod to the base Product class.

Hi,

Thanks for the reply.

I'm a bit confused about what this does. Can you explain a little bit.
I'd like to understand what is going on in the above code a little better.

Thanks.