launchpad-dev team mailing list archive

[Muharem Hrnjadovic <muharem@xxxxxxxxxx>]

Francis J. Lacoste wrote:
> On December 2, 2009, Gary Poster wrote:
>> On Dec 2, 2009, at 12:47 PM, Francis J. Lacoste wrote:
>>> On December 2, 2009, Gary Poster wrote:
>>>> On Dec 2, 2009, at 11:41 AM, Muharem Hrnjadovic wrote:
>>>>> Gary Poster wrote:
>>>>>> On Dec 2, 2009, at 10:41 AM, Muharem Hrnjadovic wrote:
>>>>>>> Quick question:
>>>>>>>
>>>>>>> do we use the zope class registry anywhere?
>>>>>> I doubt it.
>>>>>>
>>>>>>> Is it safe to use within
>>>>>>> Launchpad?
>>>>>> I'd prefer to use utility registration if that can work with your use
>>>>>> case.
>>>>> Sorry for not being precise enough. In my particular case a number of
>>>>> classes would implement the interface in question (IBuildFarmJob).
>>>>>
>>>>> I understood the utility registration mechanism requires that there is
>>>>> exactly one class that implements a particular interface in which case
>>>>> I could not use it for the interface/purpose at hand.
>>>> The class registry you showed had keys and values.
>>>>
>>>> You can register different utilities for the same interface by providing
>>>> a different name for each one (I think of this as a namespace).
>>>>
>>>> You can then get all of the utilities for that interface with
>>> getUtilitiesFor.  From docs:
>>>>>>> sorted(components.getUtilitiesFor(tests.I2))
>>>> [(u'', U12(2)), (u'three', U12(3))]
>>>>
>>>> In that example, ``components`` could be obtained as follows:
>>>>
>>>> from zope.component import getSiteManager
>>>> components = getSiteManager()
>>> Another possibility is to use subscriptions. You can register components
>>> for the IBuildFarmJob interface and get all the registered subscribers.
>> Absolutely.
>>
>> FWIW, I don't like subscription adapters because their functionality can be
>>  essentially duplicated in the way I described, with named utilities.  I'm
>>  trying to reduce the number of things to learn about in Zope's Component
>>  Architecture in zope-dev.  So I don't recommend them...but that's just me.
>>  :-)
> 
> Then what Gary says :-) 

Thanking you both for the great advice :)

Best regards

-- 
Muharem Hrnjadovic <muharem@xxxxxxxxxx>
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