--- In flexcoders@yahoogroups.com, Mark Carter <[EMAIL PROTECTED]> wrote: > > > Thanks for that Amy. > > Doesn't that only work if you have a set isAllowed() as well?
No. There is intentionally no setter function for isAllowed for the reason you outline below: > Unfortunately, in my scenario, isAllowed() is not set in this kind of way - > its more of a calculation based on various vars elsewhere (some > non-bindable). Yes, that's why you dispatch the binding event any time one of the variables involved in the calculation changes, to tell Flex it needs to go look at the getter function to see what the new variable is. How else do you think Flex is going to just "know" to run the function? Although you did have a point in your first statement above that another way to do it would be to simply run your setter function every time the value changes and let the normal binding mechanism do its thing. However, using the getter only approach has these advantages: 1) Limits the binding trigger to only your custom event, which means that any other more normal bindings you have aren't going to fire when your custom binding fires (more efficient) 2) For this to work, it has to be a public getter, which means a public setter. So if you use a public setter, you run the risk that someone using your component could try to set that value inappropriately. You might find this presentation informative http://link.brightcove.com/services/player/bcpid1733261879? bclid=1729365228&bctid=1741212660 HTH; Amy