I want to know if it's being changed. I have a controller object that will need to recalculate some values when a specific attribute changes in the EO.
-Lon On Thu, Jul 9, 2009 at 1:42 PM, Mark Morris<[email protected]> wrote: > Just a clarification, do you want to know when the value changes, even if > it's not saved to the database? Or do you just want to know if a change is > being saved? That would make a difference. ;-) > > Regards, > Mark > > On Jul 9, 2009, at 3:28 PM, Lon Varscsak wrote: > >> Uh, another question. :) Since I have a custom EO super-super class, >> I decided to try to implement this in takeStoredValueForKey(..). >> >> It works, although I was also trying to post the "old" value, and >> asking for this current value at this point makes EOF not so >> happy...but that's not strictly required for my needs. >> >> However, it does post notifications even for fetched objects, what >> would be the best way to only post changes after fetching? >> >> Thanks again, >> >> Lon >> >> On Thu, Jul 9, 2009 at 12:43 PM, Lon Varscsak<[email protected]> >> wrote: >>> >>> Thanks for the tips! >>> >>> -Lon >>> >>> On Thu, Jul 9, 2009 at 12:34 PM, Chuck Hill<[email protected]> >>> wrote: >>>> >>>> On Jul 9, 2009, at 12:26 PM, Lon Varscsak wrote: >>>> >>>>> Thanks. I figured there was nothing built to do exactly what I >>>>> needed, but I figured I would ask. >>>>> >>>>> Do you know if there is much overhead if I implemented this in my EO >>>>> superclass even if there were no observers? >>>> >>>> EOF makes heavy use of notification. I would not expect there to be >>>> much >>>> overhead. You will probably want to qualify the notification with the >>>> EC >>>> (depending on what it is you are trying to do) to limit the number of >>>> observers. And then keep the method receiving the notification fast. >>>> The >>>> notifications are synchronous, so you don't want anything slow in this >>>> method. >>>> >>>> >>>> Chuck >>>> >>>> >>>> >>>>> >>>>> -Lon >>>>> >>>>> On Thu, Jul 9, 2009 at 11:50 AM, Simon McLean<[email protected]> >>>>> wrote: >>>>>> >>>>>> also, if you are using wonder, check out >>>>>> hasKeyChangedFromCommittedSnapshot in ERXGenericRecord. maybe listen >>>>>> for the notification mentioned by chuck, then use >>>>>> hasKeyChangedFromCommittedSnapshot to check the particular key you are >>>>>> looking at. >>>>>> >>>>>> simon >>>>>> >>>>>> 2009/7/9 Chuck Hill <[email protected]>: >>>>>>> >>>>>>> On Jul 9, 2009, at 10:24 AM, Lon Varscsak wrote: >>>>>>> >>>>>>>> Is there a way for a controller object to listen for changes to an >>>>>>>> EO >>>>>>>> (and a specific key)? >>>>>>>> >>>>>>>> Thanks, >>>>>>>> >>>>>>>> Lon >>>>>>> >>>>>>> EOEditingContext has ObjectsChangedInEditingContextNotification, but >>>>>>> it >>>>>>> is >>>>>>> on an object by object basis, not a key by key one. >>>>>>> >>>>>>> You could implement this in your EO super class. >>>>>>> >>>>>>> >>>>>>> Chuck >>>>>>> >>>>>>> -- >>>>>>> Chuck Hill Senior Consultant / VP Development >>>>>>> >>>>>>> Practical WebObjects - for developers who want to increase their >>>>>>> overall >>>>>>> knowledge of WebObjects or who are trying to solve specific problems. >>>>>>> http://www.global-village.net/products/practical_webobjects >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> Do not post admin requests to the list. They will be ignored. >>>>>>> Webobjects-dev mailing list ([email protected]) >>>>>>> Help/Unsubscribe/Update your Subscription: >>>>>>> >>>>>>> >>>>>>> http://lists.apple.com/mailman/options/webobjects-dev/simon%40potwells.co.uk >>>>>>> >>>>>>> This email sent to [email protected] >>>>>>> >>>>>> >>>>> >>>> >>>> -- >>>> Chuck Hill Senior Consultant / VP Development >>>> >>>> Practical WebObjects - for developers who want to increase their overall >>>> knowledge of WebObjects or who are trying to solve specific problems. >>>> http://www.global-village.net/products/practical_webobjects >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>> >> _______________________________________________ >> Do not post admin requests to the list. They will be ignored. >> Webobjects-dev mailing list ([email protected]) >> Help/Unsubscribe/Update your Subscription: >> >> http://lists.apple.com/mailman/options/webobjects-dev/markm%40onpointsoftware.com >> >> This email sent to [email protected] >> > > _______________________________________________ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to [email protected]
