How to override Django's signal handler?

Question

in a Django shop application there gets registered signal handler to some action like adding an item to the cart.

I'd like to replace this handler with my own version in localsite/models.py, ie. without touching original sources.

If just calling connect method

signals.satchmo_cart_add_verify.connect(my_veto_out_of_stock)

the custom handler appends to the list of current recievers and the original still gets an action:

print signals.satchmo_cart_add_verify.receivers
"""
[((140073113515864, 140073319632416), <weakref at 0x7f65502c1aa0;
to 'function' at 0x7f65502c7758 (veto_out_of_stock)>),
((140073114981632, 140073319632416), <weakref at 0x7f65504295d0;
to 'function' at 0x7f655042d500 (my_veto_out_of_stock)>)]
"""

I can in an advance remove the original handlers with

for hnd in signals.satchmo_cart_add_verify.receivers:
    del hnd

but find it ugly and hackish.

So what's the proper way to replace the signal handler ?

Thanks

I've just found one way. Importing the original handler function and passing it to `signals..disconnect` but is there some more generic way even when importing the original function is not possible ? — David Unric, Mar 25 '13 at 15:09
If you cannot import the original function (because you don't know where it is when programming?), you could get the receiver func by something like `signals.satchmo_cart_add_verify.receivers[0][1]()` — okm, Mar 25 '13 at 15:17

okm · Accepted Answer · 2013-03-25T15:33:54.713

2

Have your tried Signal.disconnect?

signals.satchmo_cart_add_verify.disconnect(
    signals.satchmo_cart_add_verify.receivers[0][1]())

This way is clear IMO.

edited Mar 25 '13 at 15:33

answered Mar 25 '13 at 15:10

okm

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If nobody else would complain about *clarity* of this solution, I'm going to accept this answer. – David Unric Mar 25 '13 at 19:12

How to override Django's signal handler?

1 Answers1