Mark Stuart wrote:
You HAVE to declare the global again, and again where needed.
I'd rather it once declared and a value put into it, the value be available
elsewhere WITHOUT having to declare it again.
As Jacque pointed out, LC and related dialects are very forgiving with
the scope of variable names, so it's possible to have one token used as
a global, a local, and an argument. To avoid confusing the compiler, we
need to declare globals in any script that uses them.
If that one line of code at the top of a script is cumbersome (and in
some complex code bases it may well be), try accessors instead:
-- In a mainstack, library, backscript, or other globally-available
-- script:
global gDefaultWidgetHeight
command SetDefaultWidgetHeight pVal
put pVal into gDefaultWidgetHeight
end SetDefaultWidgetHeight
function GetDefaultWidgetHeight
return gDefaultWidgetHeight
end GetDefaultWidgetHeight
---
With those in place you can get and set the value stored in the global
from any other script without a declaration, e.g.:
set the height of grp 1 to GetDefaultWidgetHeight()
SetDefaultWidgetHeight 200
Another benefit to using accessors is that they help factor code; that
is, you can change how you store that value at any time without having
to modify any code that relies on it. Today it might be a global, but
two versions from now it might be a database record; with accessors, you
only change two handlers and everything else comes along for the ride.
True, using accessors will impair performance relative to calling the
global directly. But in practical terms you're only looking at a
fraction of a *micro*second, so if you need to liberate your code base
from direct storage references chances are no one will ever notice the
performance difference.
--
Richard Gaskin
Fourth World
LiveCode training and consulting: http://www.fourthworld.com
Webzine for LiveCode developers: http://www.LiveCodeJournal.com
LiveCode Journal blog: http://LiveCodejournal.com/blog.irv
_______________________________________________
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
