Re: Synchronizing data displayed by two instances of my app
Re: Synchronizing data displayed by two instances of my app
- Subject: Re: Synchronizing data displayed by two instances of my app
- From: Sam Hart <email@hidden>
- Date: Tue, 6 Apr 2004 13:41:20 +0100
On Tuesday, April 6, 2004, at 11:31 am, Denis Stanton wrote:
I have found mention of change notification and posting a
notification, but so far I can't find how apps register to receive and
respond. More reading to do.
actually it sits on the object store, if something changes ( willChange
? ) it sends out a notification
apps listen and when they receives, they invalidate.
In a single app it isn't needed, at least it shouldn't be, if it is
you are in trouble.
In Cocoa there are notifications pasted and detected in a single app -
or at least there are in the one I have written, drawing on code
examples from Bill Cheeseman's books Cocoa Recipes for OS X.
Notifications are used to communicate between the data and view
segments of the program so that a change to the data store is
reflected in the screen display. It puzzled me for a while, as it
would be possible for the data storage procedure to call the display
update directly, but it does make the code simpler if the display
section is just told to wait for a notification to arrive.
oh right I see, this is a completely different scenario, but similar in
that you only invalidate when you need to.
Effectively it is caching for multiple processors*, if "my" data
changes, I invalidate "your" copy.
There are a couple of freely available CN frameworks out there, some
are good, some are .. well crap !
but I am up to my eyes in it today, so you will have to go it alone ...
S a m
* clusters fall under the category of multiple processors
------------------------------------------------------------------------
------
Drawing on my fine command of language, I said nothing.
_______________________________________________
webobjects-dev mailing list | email@hidden
Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/webobjects-dev
Do not post admin requests to the list. They will be ignored.