[Grok-dev] indexes not getting updated for contents added via ApplicationInitializedEvent subscriber

[Souheil CHELFOUH]

Hey Joshua,

You got that right, good work for getting that straight and working.
Thank you for the explanations, I hope it will help other people too !

- Souheil

2012/11/27 Joshua Immanuel <josh at hipro.co.in>:
> Hello list,
>
> On Mon, 2012-11-26 at 14:59 +0530, Joshua Immanuel wrote:
>> This is how my subscriber looks like
>>
>>         @grok.subscribe(IMyRoot, grok.ApplicationInitializedEvent)
>>         def cbAppRootAdded(app_root, event):
>>             catalog = component.queryUtility(ICatalog,
>> context=app_root)
>>             # catalog is not None
>>             intids = component.queryUtility(
>>                 IIntIds, context=app_root, default=None)
>>             # intids is also not None
>>
>>             my_folder = MyFolder() # grok.Container object
>>             my_default_object = MyObject(...) # grok.Model object
>>             grok.notify(grok.ObjectCreatedEvent(my_default_object))
>>             my_folder['default_object'] = my_default_object
>>             app_root['my_folder'] = my_folder
>>             transaction.commit()
>>
>> I even tried adding the default object via IObjectAddedEvent
>> subscriber for IMyFolder. Still, the indexes for MyObject were not
>> getting updated.
>
> I spoke to @trollfot in IRC channel, he was very patient and kind to
> answer my queries. This is the abstract of the talk. Please correct it,
> if I am wrong or if I have missed anything.
>
> Inside the subscriber of ApplicationInitializedEvent we can count on the
> fact that the local utilities such as Catalog and IntIds will be
> registered. As we know that the utilities are looked up in site manager,
> so during a traversal the registry lookups will be set to application
> root's ('MyRoot' as per the above example code) site manager. But,
> ApplicationInitializedEvent is triggered by Grok Admin, as our
> application is not yet traversed at that time, the current site manager
> at that point will be the global site manager. So, we won't be getting
> the local utilities registers for our IMyRoot. Thereby our indexes
> registered will not get updated if we add the object at that time.
>
> We need to instruct Grok to use the local site manager of our
> application root for lookups inside our subscriber code. Since IntIds
> requires that the object should be persisted in order to generate int
> ids. We need to add the 'my_folder' to app_root then add MyObject to it.
> So our modified code will look like this
>
>         from zope.component.hooks import setSite, getSite
>
>         @grok.subscribe(IKalam, grok.ApplicationInitializedEvent)
>         def cbAppRootAdded(app_root, event):
>             previous_sm = getSite()
>             # Instruct Grok to use our app_root's local site manager
>             setSite(app_root)
>
>             my_folder = MyFolder() # grok.Container object
>             # First persist the container object
>             app_root['my_folder'] = user_folder
>             my_default_object = MyObject(...) # grok.Model object
>             # Persist our object so that IntIds can be generated
>             my_folder['default_object'] = my_default_object
>             transaction.commit()
>             # restore back to original site manager
>             setSite(previous_sm)
>
> The above code works perfectly. I would like to thank @trollfot for his
> time and help.
> --
> Joshua Immanuel
> HiPro IT Solutions Private Limited
> http://hipro.co.in
>
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