Where can I define my widget's preference?

[gaoxiang]

On Thursday 28 June 2012 17:49:30 gaoxiang wrote:
> I think I'm having trouble with documentions.  These documentations gives
> little information.  I have not find any tutorials or documentations on
> where and how my widget's preference should be defined so I have to ask
> here. Please give some links or hints on how I should do these things.
> After my program finish, I will write something about the help I got to
> enrich our documentations.
> Thanks.

I downloaded the project kdeplasma-addons's source code for a reference and 
created my contents/ui/config.ui now.  But I don't know how to access the value 
of configs througt javascript.  Could anyone give me some help?