[cells-devel] Lots of instances, callback when particular instance changes

[Josip Gracin]

Here's what I'm currently doing (just an outline):

(defmodel switch (component)
   ((switch-position :cell t
                     :initarg :switch-position
                     :initform (c-in :off)
                     :accessor switch-position)
    (change-handler :cell nil
                    :initform nil
                    :initarg :change-handler
                    :reader switch-change-handler)))


(def-c-output switch-position (self new-value old-value)
   (when (switch-change-handler self)
     (funcall (switch-change-handler self) self new-value old-value)))

And then create instances:

...
(mksys 'switch :main-battery-switch)
(mksys 'switch :apu-start-switch                           			 
:change-handler 'apu-start-switch-change-handler)
...

The reason I need the change handler is that the change handler has to 
modify the value of the self switch.  For example, when apu-start-switch 
changes its value to :START, change handler schedules an action which 
will set the switch back to :ON after some time.  I fail to see how I 
can do this using regular slot-dependency mechanisms provided by Cells.

Am I making any sense?