EOF and the Observer Pattern
EOF and the Observer Pattern
- Subject: EOF and the Observer Pattern
- From: David Avendasora <email@hidden>
- Date: Thu, 30 Oct 2008 05:44:35 -0400
Hi all,
I have several places in my application where a large number of EOs
exist in the DB that are directly dependent upon other EOs. If the
depended-upon EOs change, then all the dependent EOs may need to be
updated.
This seems to me like the perfect use of the Observer Pattern.
For example. If a Part's BOM is updated the nutrition information for
that Part may need to be updated as well. Calculating the current
nutrition information is too expensive to do it everywhere it is
needed so it is saved in the database. I also maintain historical
nutritional information as well and that shouldn't be updated, only
the current information should be.
What I'd like to do is to have the "current" Nutrition object observe
the Part object. If the Part object is updated in a significant way,
then the Nutrition object will get notified to update itself.
What I'm trying to figure out is how to persist this information. I
don't think I want to model the relationship, do I?
I looked at EOObserving but I think that's more about catching changes
between two objects already in memory.
How would I model EOEnterpriseObject <<->> EOEnterpriseObject anyway?
Using EOIDs?
Dave
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden