Re: set_rebind_proc

[<mi...@st...>]

Steffen Ries wrote:
> 
>>I have to admit that I'm scared about adding such functionality into
>>the C part of python-ldap. I'd like to encourage you to find a
>>Python-only solution which is easier to maintain. BTW: That's exactly
>>one of the benefits of class ldap.ldapobject.LDAPObject: It can be
>>sub-classed for extending its functionality.
> 
> Hmm. Implementing a Python-only solution would require to catch the
> ldap.REFERRAL (or ldap.PARTIAL_RESULT) for each of the operations,
> decide how to chase the referral and then retry the operation. I can
> try to come up with a proposal...
 > [..]
>>I'd rather like to see a framework which helps the application
>>developer to implement generic exception handlers for
>>e.g. ldap.SERVER_DOWN or ldap.REFERRAL and decide what to do in
>>his/her specific environment.
> 
> Are you thinking of registering error specific exception handlers or
> pushing the functionality to the application?

LDAPObject._ldap_call could be the point from where registered 
exception handlers are called. E.g. a new method 
LDAPObject.ErrorHandler(e,func,args,kwargs) could check whether a 
generic handler method is registered for a specific LDAPError 
class and call that handler with these parameters.

Now the application would sub-class LDAPObject and implement such 
handlers applying the specific knowledge about the environment.

Note that we have the advantage of having OO-oriented API and 
exceptions. Therefore we aren't limited to such crude mechanisms 
common in C like call-back functions. IMHO we should think in this 
direction.

> I would like to add some functionality to the library (call it a
> framework), rather than burden the application to wrap every
> search/add/modify with an exception handler for chasing referrals. I
> have this kind of code in some places for fail over, which makes it
> pretty hard to maintain.

Well, I'd like to have something in the python-ldap library too. 
But although it sounds pretty easy I guess it's not. There are 
some caveats I'm sure (e.g. some kind of nested error handling in 
exception handlers...).

Ciao, Michael.