[FIXED] Django : can't return redirect in a sub function exception. The first function continues

Issue

I've got a function a() that calls other functions b() , c() and d() this way (I schematize):

a()

def a(request):
    try:
        b(request)
    except Exception:
        messages.error(request, 'error')
    try:
        c(request)
    except Exception:
        messages.error(request, 'error')
    try:
        d(request)
    except Exception:
        messages.error(request, 'error')
    return redirect('namespace:url_name')

b()

def b(request):
    try:
        do_something()
        messages.success(request, 'I did')
    except Exception:
        messages.error(request, 'Couldn\'t do the thing')
        return redirect('namespace:url_name')

But if an exception triggers in b() , its redirection doesn't work and c() and d() are still executed in a().

Did I miss something in my redirect or exception handling comprehension ? Because even if I set a redirect in all a functions' Exceptions, the behavior doesn't change.

Solution

You don't return the result of b in a, so, regardless what b returns, it will still process c, and d. The return redirect will return, but it will return out of b, it does not return out of the callers of b, that doe snot make much sense.

We thus should check if b returns something, if that is the case, return the result, otherwise continue:

def a(request):
    try:
        result = b(request)
        if result is not None:
            return result
    except Exception:
        messages.error(request, 'error')
    try:
        result = c(request)
        if result is not None:
            return result
    except Exception:
        messages.error(request, 'error')
    try:
        result = d(request)
        if result is not None:
            return result
    except Exception:
        messages.error(request, 'error')
    return redirect('namespace:url_name')

Answered By - willeM_ Van Onsem