Re: [Wonder-disc] refreshRefetchedObjects

[Chuck H. <ch...@gl...>]

On 2013-03-08, at 6:14 PM, Ramsey Gurley wrote:

> 
> On Mar 8, 2013, at 6:15 PM, Aaron Rosenzweig wrote:
> 
>> Hey Ramsey and friends,
>> 
>> If you were studying numerical data, you wouldn't expect that by hitting the browser refresh button on your browser that the data spread would look different. That's just one example. That would mess up your standard deviation calculation. What the ?!? I could have sworn that value was 20 not 28 a second ago.
>> 
>> Yes, you are right, it would seem silly to most people that if you spent the time to hit the database, you might as well show the results of that fetch.

I believe it was for performance.  Updating the snapshots and propagating those changes to all ECs takes some time.  If all you wanted was objects that you did not already have in memory, why pay that penalty?


Chuck


>> But, that is not what NeXT designers wanted as a default. They understood that many people would want that so gave you the boolean flag... If I had to guess, they wanted to flex their mental muscles and make a point about how the EOEditingContext is a "consistent view" of your data. As long as you are working with the data there shouldn't be surprises from other people using the system. I believe that was their mantra.
> 
> 
> Okay, that kinda explains it, but it doesn't make it any less bonkers to me :-) 
> 
> The same thing happens anyway when a peer ec is saved. The snapshot is updated and the changes are automatically merged into the user's edited object even though the user may never see them on the client page. Mark Ritchie made sure to point that out a couple of times in his WOWODC09 presentation. (Can you guess what I was watching today?) It seems inconsistent that it would handle a changed snapshot any differently when fetching.
> 
> After reading the wiki on data freshness, I got the impression that setting it to true was buggy, so I thought maybe that was the issue.
> 
> http://wiki.wocommunity.org/display/documentation/EOF-Using+EOF-Caching+and+Freshness
> 
> In any case, I definitely learned something today :-)  Somehow I've walked in between the rain up to now.
> 
> Ramsey
> 
> 
>> Other people have had a similar beef with "addObjectToBothSidesOfRelationshipWithKey()." They ask "When would you not want to do that?" 9 times out of ten you always want to and in Cayanne that is the default. But in WO we can add to just one side. Why? Because there might be a painful back relationship you don't feel like tripping. You could argue to remove the back relationship from the model... but if that wasn't up to you, and you didn't want the performance penalty, you can simply add the to-one side of the relationship and not both sides.
>> 
>> I have a bigger beef with the wocomponent only known its parent. I feel it should know its children instead. Why does the tire need to know the car it is on? It should just know how to spin and chirp when tire pressure is low. The car should be the one to know what tires it has. 
>> 
>> Much of this is "that just the way it is" and we may never know the true reasons. At least most of the time the NeXT guys gave us hooks to do what we want, that's great. They preach but then let us do what we want anyway.
>> AARON ROSENZWEIG / Chat 'n Bike
>> e:  aa...@ch...  t:  (301) 956-2319 		
>> 	
>> 
>> On Mar 8, 2013, at 7:11 PM, Ramsey Gurley wrote:
>> 
>>> The default for refreshesRefetchedObjects is false. Why? That's what doesn't make any sense to me.  When is that behavior ever desirable?
>> 
>> ------------------------------------------------------------------------------
>> Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester  
>> Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the  
>> endpoint security space. For insight on selecting the right partner to 
>> tackle endpoint security challenges, access the full report. 
>> http://p.sf.net/sfu/symantec-dev2dev_______________________________________________
>> Wonder-disc mailing list
>> Won...@li...
>> https://lists.sourceforge.net/lists/listinfo/wonder-disc
> 
> ------------------------------------------------------------------------------
> Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester  
> Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the  
> endpoint security space. For insight on selecting the right partner to 
> tackle endpoint security challenges, access the full report. 
> http://p.sf.net/sfu/symantec-dev2dev_______________________________________________
> Wonder-disc mailing list
> Won...@li...
> https://lists.sourceforge.net/lists/listinfo/wonder-disc

-- 
Chuck Hill             
Executive Managing Partner, VP Development and Technical Services

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/gvc/practical_webobjects

Global Village Consulting ranks 13th in 2012 in BIV's Top 100 Fastest Growing Companies in B.C! 
Global Village Consulting ranks 76th in 24th annual PROFIT 200 ranking of Canada’s Fastest-Growing Companies by PROFIT Magazine!