Thanks Igor, but you're talking about where constants can be declared; I
was talking about where they can be used.
I read the dictionary the same way you do, in the context of declaration
(constants can be declared within or outwith handlers, with different
context). And I agree with Mark that redefining a constant is a bad idea.
But neither of those was my issue - in my reply to Craig I did what I
should have done in the first place and included a complete script
showing the problem. Constants that have been properly, globally
declared can be used within handlers but do not take effect outside
handlers.
So in a revserver that is "just one big script" you cannot use the
constants except within any handlers.
-- Alex.
On 29/05/2012 05:51, Igor de Oliveira Couto wrote:
Alex, I don't know if you and I are reading the dictionary in the same way:
On 29/05/2012, at 9:00 AM, Alex Tweedly wrote:
[...]
The dictionary entry for constant says:
If you place the constant statement in a handler, you can use the constant
anywhere in the handler. If you place the constant statement in a script
outside any handler, you can use the constant anywhere in the handlers of that
script.
NB - "can use the constant anywhere *in the handlers* of that script".
That was a reasonable limitation in traditional Livecode - but seems less
reasonable in the context of revserver.
[...]
I *think* what the dictionary means - and please someone correct me if I'm
wrong - is that there are 2 ways to declare a constant value: INSIDE a handler
(like inside a mouseUp, enterField, etc.), or OUTSIDE any handlers (the same
way you'd declare a SCRIPT VARIABLE). The 2 ways would be like this:
INSIDE A HANDLER
on enterField
constant kIncrease = 3
answer kIncrease
end enterField
The problem with declaring the constant that way, is that it is defined only
for THAT specific 'enterField' handler. If you also had a second handler that
expected to use that value, such as...:
on closeField
answer kIncrease
end closeField
...that would fail, because 'kIncrease' is defined only inside 'enterField'. To
overcome that, you can declare the constant like this:
OUTSIDE HANDLERS
contant kIncrease = 3
on enterField
answer kIncrease
end enterField
on exitField
answer kIncrease
end exitField
...would work, as 'kIncrease' will now be available to *all* handlers.
In the context of revServer, this still applies. For instance: if your
revServer application is just one big script - ie., a 'main' script that
'includes' or 'requires' others (which is, in effect, the same as having one
long script) - then a constant declaration outside all handlers will in effect
make it a global constant.
I hope this helps!
--
Igor Couto
Sydney, Australia
_______________________________________________
use-livecode mailing list
use-livecode@lists.runrev.com
Please visit this url to subscribe, unsubscribe and manage your subscription
preferences:
http://lists.runrev.com/mailman/listinfo/use-livecode
_______________________________________________
use-livecode mailing list
use-livecode@lists.runrev.com
Please visit this url to subscribe, unsubscribe and manage your subscription
preferences:
http://lists.runrev.com/mailman/listinfo/use-livecode
