Infinite loop when notifying model delegates of load start when the model is outdated

CVertex

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Jul 27, 2009, 5:18:59 AM7/27/09

to Three20

Howdy,

My models derive from TTModel with alot of the automatic stuff it
offers.

I notify my model listeners that loading has started like so

- (void)load:(TTURLRequestCachePolicy)cachePolicy more:(BOOL)more {
[_delegates perform:@selector(modelDidStartLoad:) withObject:self];

// start http request for stuff

}

Since TTModel uses the cache for it's stuff, the cache key eventually
becomes outdated and model.IsOutdated returns false. This actually
happens inside the TTModelViewController listener of
modelDidStartLoad:. So, when modelDidStartLoad is called from load:,
TTModelViewController does some stuff to update it's state, then
called reloadIfNeeded and calls load again, resulting in an infinite
loop.

I removed the delegate notification from load:cachePolicy:more:, but
then there's no obvious hook to tell the controller the model is
loading.

Does anyone know how to get around this issue?
Or during the update to TTModel, was something changed that I didn't
change appropriately in my code.

Any help is greatly appreciated,

-CV

CVertex

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Jul 27, 2009, 5:37:53 AM7/27/09

to Three20

Just looking through the latest and it appears to be fixed.. should i
upgrade to the latest master three20? or is there a simple patch I can
apply to fix this issue for the time being?

garybu

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Aug 1, 2009, 8:41:38 PM8/1/09

to Three20

I see the same same problem. Should TTModelViewController
shouldReload include a check for model.isLoading?

- (BOOL)shouldReload {
return !_modelError && self.model.isOutdated && !
self.model.isLoading;

klazuka

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Aug 2, 2009, 5:52:14 AM8/2/09

to Three20

Seems right to me, but TTModelViewController is such a monstrous state
machine that it is difficult to reason about.

I think I was bitten by this same bug on Friday... thanks for bringing
this up.

-keith