Django: parametric class-based views

Question

I am trying to use generic CreateView class to handle forms for a set of models inherited from the same base class.

class BaseContent(models.Model):
    ...

class XContent(BaseContent):
    ...

class YContent(BaseContent):
    ...

To keep things DRY, I want to define one CreateView class that will handle all inherited classes from BaseContent.

The url pattern for that view is:

url(r'^content/add/(?P<model_name>\w+)/$', ContentCreateView.as_view(), name='content_add')

Something like this should work:

class ContentCreateView(CreateView):
    template_name = 'content_form.html'

    def get_model(self, request):
        # 'content' is the name of the application; model_name is 'xcontent', 'ycontent', ...
        return ContentType.objects.get_by_natural_key('content', self.model_name)

But I am getting this exception:

ContentCreateView is missing a queryset. Define ContentCreateView.model, ContentCreateView.queryset, or override ContentCreateView.get_object().

This suggestion does not seem to hold as I am not willing to set a class attribute like model or queryset to keep the model form generated dynamic. Overriding the get_object does not seem relevant for creating an object.

I tried overriding get_queryset() but this method does not accept the request parameter, nor have access to self.model_name which comes from the url pattern.

Long story short, how can I make a CreateView use a dynamic form based on a parameter passed from the url?

Thanks.

Answer 1

You could set the model attribute from your your urls.py, depending on the url being called:

url(r'^content/add/x/$', 
    ContentCreateView.as_view(model=XContent), name='x_content_add'),
url(r'^content/add/y/$', 
    ContentCreateView.as_view(model=YContent), name='y_content_add')

I admit it's not perfect as you are repeating yourself a bit, but therefore you have the advantage of having different names for the same view, depending on the model! Besides that you could also do something similar with overriding form_class...