Re: [Modeling-users] slooow delete

[John L. <jl...@gm...>]

On 11 Mar 2005 22:19:37 +0100, Sebastien Bigaret
<sbi...@us...> wrote:
> 
> *Big fat warning* (!): do that if you're absolutely sure that the
>     related 'need', 'team' and 'mealType' objects are not already
>     fetched in other ECs, *or*, if they are fetched, that the "inverse"
>     tomany faults are not cleared.

If I read you correctly then I'm safe, because I never do

    need.setTasks(None)

(is this what you mean by clearing the tomany faults?)

> 
>     Respectively, check that (for 'need', same for 'team' and
>     'mealType'):
> 
>       db=ec.rootObjectStore().objectStoreForObject(task).database()
> 
>       task_need_gID=task.getNeed().globalID()
>       db.snapshotForGlobalID(task_need_gID=task) # None if unfetched yet
> 
>     and if it's not None:
> 
>       db.snapshotForSourceGlobalID(task_need_gID, 'tasks')  # should be ()
> 
>     Otherwise you may experience weird side-effects on the corresponding
>     objects already fetched in other ECs, esp. when saving them (no
>     pb. if you use a single EC in the app., however).

I'm not clear what the purpose of this is: is it to ensure that the
task.setMeal(None) is safe?

basically what I'll be doing, unless you tell me otherwise, is:

  - for creating, do the task.setMeal(meal) but not the meal.addToTasks(task)
  - for deleteing, do the task.setMeal(None) but not the
meal.removeFromTasks(task)

given that I never, ever (promise! :D) clear the tasks, and that I
always saveChanges after deleteing or creating each task, although I
have many editingContexts (inside zope, one per session using
ZEditingContextSessioning), it is my understanding that I'll be safe.
Right?

-- 
John Lenton (jl...@gm...) -- Random fortune:
Don't anthropomorphise computers and cars, They hate that.