[Freeipa-devel] [PATCH] radius work, please review

[John Dennis]

Karl MacMillan wrote:
> On Thu, 2007-11-29 at 17:53 -0500, John Dennis wrote:
>> Karl MacMillan wrote:
>>> On Thu, 2007-11-29 at 16:15 -0500, Rob Crittenden wrote:
>>>> John Dennis wrote:
>>> [...]
>>>
>>>> 4. As you can see in each tool there is a bunch of duplicated code (all 
>>>> the error catching at the end for example). Do you know of a way we can 
>>>> generalize that in Python and put it into a client library?

>>> Decorators? (I think that is in python 2.4)

>> I'm pretty familiar with decorators, it's a nice feature, but I don't 
>> think it has application in this context. Decorators can be used to add 
>> meta-data to functions and/or alias the function to a specific use by 
>> returning a runtime generated function which end up being a "proxy" for 
>> the decorated function. This feature makes it wonderful for implementing 
>> RPC. But perhaps I'm not following your vision of how a decorator might 
>> be used to reduce the code duplication.

> Much of the error checking (especially for generic things like
> connection errors) could be added to functions through a decorator. So,
> for example, a function to add a user *would* check for duplicate users
> to generate nice error messages but would let generic errors bubble up
> and let them be caught by the decorator wrapper.

Thank you Karl for expanding my thinking, yes I see how this might work.

Here is a good article that explains the technique:

Python 2.4 Decorators
Reducing code duplication and consolidating knowledge
http://www.ddj.com/web-development/184406073


-- 
John Dennis <jdennis at redhat.com>