EXAMPLE

from .views import View, Redirect
from .views import Viewmodel
from . import models
from django.shortcuts import get_object_or_404
from django.contrib.auth.decorators import login_required

class WholesalerItem(Viewmodel):
    model = models.Item
    fields = ['cost', 'wh_markup']

    @property
    def price(self):
        return self.cost + self.wh_markup

class RetailItem(Viewmodel):
    model = models.Foo
    exclude = ['wh_markup']

    @property
    def price(self):
        return self.cost + self.retail_markup

class ItemView(View):
    viewmodels = { 'item' : RetailItem }
    template_name = 'item.html'

    def init_request(self, request=None, item_id=None, *args, **kwargs):
        try:
            profile = request.user.get_profile()
            if profile.type == 'wholesaler':
                self.viewmodels['item'] = WholesalerItem
        except models.Profile.DoesNotExist: pass
        if not item_id:
            raise Redirect("item_list")
        item = get_object_or_404(models.Item, pk=item_id)
        return dict(item=item)

    def get(self, request=None, item=None, *args, **kwargs):
        return dict(item=item)

    @login_required
    def post(self, request=None, item=None, *args, **kwargs):
        if 'cart' not in request.session:
            request.session['cart'] = models.Cart()
        request.session['cart'].add_item(item)
        raise Redirect("cart")