djadhere/adhesions/views.py

from django.contrib.auth.decorators import login_required
from django.core.exceptions import PermissionDenied
from django.shortcuts import render, get_object_or_404

from .models import User, Corporation


@login_required
def user(request):
    # request.user is concrete model whereas user is proxy model
    user = User.objects.get(pk=request.user.pk)
    return render(request, 'adhesions/user.html', {
        'adherent': user,
        'adhesion': user.adhesion,
    })

@login_required
def corporation(request, pk):
    corporation = get_object_or_404(Corporation, pk=pk)
    try:
        corporation.members.get(pk=request.user.pk)
    except User.DoesNotExist:
        raise PermissionDenied
    return render(request, 'adhesions/corporation.html', {
        'adherent': corporation,
        'adhesion': corporation.adhesion,
    })