from django.http import HttpResponseRedirect
from functools import wraps

def permission(permission_tester):
    @wraps(permission_tester)
    def view_decorator(view_function):
        @wraps(view_decorator)
        def decorated_view(request, *args, **kwargs):
            if permission_tester(request, *args, **kwargs):
                view_result = view_function(request, *args, **kwargs)
            else:
                try:
                    request.user.message_set.create(message="Sorry, you don't have the necessary permissions to view that page.")
                except: pass
                view_result = HttpResponseRedirect("/")
            return view_result
        return decorated_view
    return view_decorator