item loop in _lazyLoadItems caches item length can cause exception

[zspitzer]

Because the length of the item array is being cached, it's possible for an exception to be triggered in _isInLoadableArea, "element is undefined" if a loader with a callback is used and the size of the item array is reduced by another round of _lazyLoadItems being executed which removes one or more items from the item array, whilst waiting for the loader to return.

https://github.com/eisbehr-/jquery.lazy/blob/master/jquery.lazy.js#L305

[dkern]

Hi @zspitzer,

I'm actually not sure, how this could happen. Inside the for loop the object is given by items[i] to the inner function. This should mean, even if the object would be removed from the items array, it is still available to the inner loop. So _isInLoadableArea should still work. I have to test this somehow ...

Do you have an example where this happens to you? Can you create a fiddle?

And if you have such problem, do you already got a workaround?

Thank you so far!

[zspitzer]

I'm on holidays and thus dad duty at the moment , so i haven't had time to knock out a fiddle. The customer loader was async as it was doing some network calls , I think _lazyLoadItems might of been triggered again whilst waiting for the server to respond.

I encountered this with some content in a dashboard which involves nested instances of lazy loaders, I was previously having issues with the destroy and namespaces which you fixed recently and thought I'd try it out and encountered the exception.

but the fix is dead simple
for( var i = 0, l = items.length; i < l; i++ )
becomes
for( var i = 0; i < items.length; i++ )

[dkern]

Ahh well, yes, of course. I was thinking that would work. But on JS it's working this way. 😉
I will make this little change within the next update ...

[dkern]

fixed as of 1.7.3