Not familiar with Pivot, so not sure what its expectations are. But creating a 
ToManyList outside Cayenne generally doesn't seem like a good idea. Maybe what 
you doing as a workaround is perfectly valid. So what is the purpose of 
creating a new list by Pivot and what happens to that list after that? Is there 
an attempt to persist it afterwords? 

Cheers,
Andrus


On Jul 12, 2012, at 8:46 AM, Tomas Stenlund wrote:

> Hi,
> 
> I'm using Cayenne 3.1B1 and Pivot 2.0.2 as a GUI and have come across 
> something which I would gladly have some good suggestions around.
> 
> The automatically generated getters for the relationships sometimes returns a 
> ToManyList of objects. To be able to use that list directly in Pivot:s 
> widgets I have to wrap it with a ListAdapter. So, now for the cayenne 
> questions, it seems that ToManyList does not have an empty constructor (maybe 
> it does not have one because it does not really mean anything in the ToMany 
> relationship) causing a call to the list.getClass().newInstance() that the 
> ListAdapter in pivot does to create a new empty list of the same type to 
> throw the InstantiationException.
> 
> It might be that the ListAdapter is wrongly implemented to assume that the 
> List:s always have an empty constructor or something else. Any ideas ? For 
> now I just create a new list (ArrayList or something similar) and fills it up 
> with the objects in the ToManyList to send it into Pivot to make it work, but 
> it does seem to give an ugly solution moving from one list type to another 
> just to come around this.
> 
> Thanks for any comments,
> 
> Cheers,
> 
> Tomas
> 

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