DiviAreaItem.addActionOnce(hook, callback, priority, context)
Same as DiviAreaItem.addAction() but the callback is unhooked again when the action is called the next time. This function ensures, that the callback is only invoked once.
Params
hook- The hook name, without an area-suffix.
 callback- The callback function.
 priority- Hook priority.
Default: 10 context- The callback context.
Default: <code>window</code> 
Returns
The function does not return anything.
Notes
No notes