No Persisters for: Arraylist

subdigital · **Posted:** Fri Jul 08, 2005 5:26 pm

I got this strange error today, and I can't seem to pinpoint it.

I know it's probably something simple, but anyway.

When saving an object, I get this error:

No Persisters for: System.Collections.ArrayList

All of my mapping files are marked as Embedded Resources, and all of my collections are of type IList, so I can't figure out what's wrong.

KPixel · **Posted:** Sun Jul 10, 2005 10:31 am

Did you map one of your collection with a class of the typeof(ArrayList)?

(You can post the content of your log.txt after enabling the DEBUG mode)

subdigital · **Posted:** Mon Jul 11, 2005 6:31 pm

can you be a little more specific?

I have lots of collections, but they are all of type IList...

for all of my private members I do the following:

Code:

private IList myCollection = new ArrayList();
public IList MyCollection
{
   //get & set
}

and I haven't had a problem until now... I assume the above is correct usage?

Are there any other common causes of this error that jump out at you?

As for logging, it IS enabled, but I don't seem to get a new log file everyday for some reason.... I only have a handful of logfiles from various days.

thejez · **Joined:** Sun Jul 10, 2005 6:30 pm **Posts:** 10

i think all you need is this and it should work fine:

Code:

private IList myCollection; 
public IList MyCollection 
{ 
   //get & set 
} 

subdigital · **Posted:** Mon Jul 11, 2005 7:15 pm

but then all of the instances where I am creating a new object in the client code will have to instantiate the list, and this is undesirable.

Say I am adding photos to one of my classes....

I shouldn't have to do this:

Code:

myObj.Photos = new ArrayList();
foreach(Photo p in PhotoList)
    myObj.Photos.Add( p );

I think it's better to declare it in the class, so the client code doesn't have to check.. This simplifies LOTS of code.

Also I have been doing this from the get-go and I haven't had problems yet....

ArrayList implements IList, so I don't see why NHibernate would complain. Maybe I'm wrong :/[/code]

thejez · **Joined:** Sun Jul 10, 2005 6:30 pm **Posts:** 10

I completely agree with you. I dont think an array or IList should every be null but rather always instanced with zero elements.

If this worked for you before than maybe thats not the problem.

KPixel · **Posted:** Tue Jul 12, 2005 12:07 pm

Can you post this full exception:

subdigital wrote:

No Persisters for: System.Collections.ArrayList

And your mapping files ?

subdigital · **Posted:** Wed Jul 13, 2005 5:44 pm

it turned out that the mapping files were fine... one of my developers was using the objects incorrectly.