Message Path Problems

[livfoss at blueyonder.co.uk]

On Sat, 25 Jan 2003 07:50:28 -0800 (PST, Jan Schenkel <janschenkel at yahoo.com> wrote:

>I suggest you go in and 'comment' each handler one at
>a time to see if that fixes the problem. This should
>help you pinpoint the offending handler.
>Maybe we can come up with a better strategy if you
>tell us what the error is you're getting at compile
>time ?

Thanks for the interest Jan. I find that I am a victim of my own stupidity (of course) but also of the error reporting in the Revo development environment. The error I got was ' Handler: can't find handler', with the value being the name of the handler I thought was missing, and on pressing the 'script' button in the error report, I got the script of the caller. So I thought that the call in the script was to a handler that wasn't there or wasn't in the message path... however after a lot of research, I found that the call did in fact take place, and the error occurred apparently within the handler (not its caller) at a 'pass' statement (which I'd put there instead of an 'exit' statement, but that's another story). I boiled it down to two stacks: a mainstack with the script:

on startUp
 answer "we are going to the substack"
 send "TryIt" to stack "TestSubstack"
end startUp

on mainStackThing
  answer "We've arrived at mainStackThing"
end mainStackThing

in the substack, the script is

on TryIt
 if the optionkey is down then
    pass TryIt
 else
   mainStackThing
end TryIt

When we use the message box to send 'startUp' to the mainstack without the option key down, we get a call of 'mainStackThing'.

When we try it with the option key down, we get the error 'can't find handler' with the value TryIt and the offending statement 'send "TryIt" to stack "TestSubstack" '. The 'script' button opens the script in the mainstack, so one is led to believe that this script can't be executed. Confusing, isn't it?

I realise that I am doing wrong stuff, but I would appreciate an explanation from someone who can understand what was really happening.

TIA

Graham

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Graham Samuel / The Living Fossil Co. / UK & France