Messages

[Mark Wieder]

Tom-

And just to make things a bit clearer:

There are three objects drinking at a bar:
A button, a card, and a stack.
The button only drinks Guinness
The card only drinks Bud Light
The stack will drink anything with alcohol

They each have a Drink handler:

in the button handler:
on Drink pSomething
  if pSomething is "Guinness" then
    answer "the button drank it"
  else
    pass Drink pSomething
  end if
end Drink

in the card handler:
on Drink pSomething
  if pSomething is "Bud Light" then
    answer "the card drank it"
  else
    pass Drink pSomething
  end if
end Drink

in the stack handler:
on Drink pSomething
  if HasAlcohol(pSomething) then
    answer "the stack drank it"
  else
    pass Drink pSomething
  end if
end Drink

The button also has a mouseUp handler:
on mouseUp
  Drink field "fromBartender"
end mouseUp

(and there's also obviously a field called "fromBartender")

Now put something into the "fromBartender" field and click the button.
The button's mouseUp handler sends the "Drink" message out to see who
catches it. And do check out Richard's writeup on this. Here's a
bonus: once you get the concept of messages, everything else falls
into place pretty easily.

Saturday, September 3, 2005, 12:19:32 PM, Dan wrote:

> Great analogy.

Indeed.

-- 
-Mark Wieder
 mwieder at ahsoftware.net