[Zope3-Users] fine grained subscriber

2007-03-28 Thread Lorenzo Gil Sanchez
Hi,

I'm writing an event subscriber to the IIntIdRemoveEvent event type. It
looks like this:

def intIdRemovedSubscriber(event):
  if IMyInterface.providedBy(event.object):
 # do some stuff with event.object

and the zcml:

subscriber
 handler=.intIdRemovedSubscriber
 for=zope.app.intid.interfaces.IIntIdRemovedEvent
 /

But I'd like to avoid the if clause inside my subscriber function by
doing something similar to this:

def intIdRemovedSubscriber(obj, event):
  # do some stuff with obj, which is garanteed to provide IMyInterface

subscriber
 handler=.intIdRemovedSubscriber
 for=.interfaces.IMyInterface
  zope.app.intid.interfaces.IIntIdRemovedEvent
 /

But when doing this second aproach my subscriber is not called. I
supposed I could do this by looking in the zope source code and finding
this in zope.app.intid.__init__.py

@adapter(ILocation, IObjectRemovedEvent)
def removeIntIdSubscriber(ob, event):
  # 

and 

subscriber handler=.removeIntIdSubscriber /

So the question is: why the intid package is succesful in registering a
subscriber only for ILocation objects and I can't do the same with
IMyInterface objects?

I want to avoid a lot of calls to my subscriber which will happend
everytime an IntId is removed from *any* object.

Thanks in advance

Lorenzo Gil

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Re: [Zope3-Users] fine grained subscriber

2007-03-28 Thread FB
Hi,

On Wed, Mar 28, 2007 at 12:16:23PM +0200, Lorenzo Gil Sanchez wrote:

[snip]

 But I'd like to avoid the if clause inside my subscriber function by
 doing something similar to this:
 
 def intIdRemovedSubscriber(obj, event):
   # do some stuff with obj, which is garanteed to provide IMyInterface
 
 subscriber
  handler=.intIdRemovedSubscriber
  for=.interfaces.IMyInterface
   zope.app.intid.interfaces.IIntIdRemovedEvent
  /

[snip]

 So the question is: why the intid package is succesful in registering a
 subscriber only for ILocation objects and I can't do the same with
 IMyInterface objects?
 
 I want to avoid a lot of calls to my subscriber which will happend
 everytime an IntId is removed from *any* object.

[snip]

You need a dispatcher - a quite common concept in zope3:

[events.py, not tested]
from zope.event import notify

def removeIntId(event):
notify(event.object,event)

def addIntId(event):
notify(event.object,event)



[configure.zcml, not tested]
   [...]
subscriber for=zope.app.intid.interfaces.IntIdAddedEvent
handler=.event.addIntId
/
subscriber for=zope.app.intid.interfaces.IntIdRemovedEvent
handler=.events.removeIntId
/
   [...]

Thanks to zope3's component infrastructure, a package (like intid) doesn't
have to provide the dispatcher - a different package providing the dispatcher
is perfectly fine.

Regards,

Frank
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Re: [Zope3-Users] fine grained subscriber

2007-03-28 Thread Lorenzo Gil Sanchez
El mié, 28-03-2007 a las 12:50 +0200, FB escribió:
 
 You need a dispatcher - a quite common concept in zope3:
 
 [events.py, not tested]
 from zope.event import notify
 
 def removeIntId(event):
   notify(event.object,event)
 

I think the notify call should be like notify((event.object, event))

 def addIntId(event):
   notify(event.object,event)
 
 
 
 [configure.zcml, not tested]
[...]
   subscriber for=zope.app.intid.interfaces.IntIdAddedEvent
   handler=.event.addIntId
   /
   subscriber for=zope.app.intid.interfaces.IntIdRemovedEvent
   handler=.events.removeIntId
   /
[...]
 
Ok, the removeIntId function is called and it dispatch the event through
the notify call.

Then, my original subscriber, e.g.:

subscriber for=.interfaces.IMyInterface
 zope.app.intid.interfaces.IIntIdRemovedEvent
handler=.events.myInterfaceIntIdRemovedSubscriber
/

is still not called. I have checked that in the removeIntId subscriber
the object in event.object provides IMyInterface, but this makes no
difference.

Anyway, thanks for this answer (and all the other answer you gave me
before) :-)

Regards,

Lorenzo

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Re: [Zope3-Users] fine grained subscriber

2007-03-28 Thread Lorenzo Gil Sanchez
El mié, 28-03-2007 a las 13:39 +0200, Lorenzo Gil Sanchez escribió:
 El mié, 28-03-2007 a las 12:50 +0200, FB escribió:
  
  You need a dispatcher - a quite common concept in zope3:
  
  [events.py, not tested]
  from zope.event import notify
  
  def removeIntId(event):
  notify(event.object,event)
  
 
I changed the removeIntId dispatcher to this code:

def removeIntId(event):
adapters = zope.component.subscribers((event.object, event), None)
for adapter in adapters:
pass # getting them does the work

and now it works!! My subscriber is called only when an IntId is removed
on objects that provide IMyInterface.

Thanks a lot Mark, for showing me the right direction.

Regards,

Lorenzo


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