Example of Proxy Model Dependency Injection

views.py

from __future__ import unicode_literals

from django.shortcuts import render
from models import Visualization
from exceptions import IncompleteDataException
from .forms import VisualizationForm
from django.contrib.auth.decorators import login_required

def _inject_visualization(name):
    if name == "infection_rate_visualization":
        return InfectionRateVisualization.objects.get(pk=name)
    if name == "friend_family_visit_visualization":
        return FriendFamilyVisitVisualization.objects.get(pk=name)
    if name == "food_request_visualization":
        return FoodRequestVisualization.objects.get(pk=name)    

@login_required
def transform(request):
    name = request.GET['script']

    if request.POST and request.FILES:
        form = VisualizaionForm(request.POST, request.FILES)

        if form.is_valid():
            input_file = request.FILES['file']
            image = None

            try:
                vizualization = _inject_visualization(pk=name)
                image = vizualization.from_data(name, input_file)

            except IncompleteDataException as e:
                return render(request, 'visualizations/form.html', {'error': e.message()})
                
        return render(request, 'visualizations/results.html', {'image': image})