Best Practices

[Erin D. Smale]

Hello all,

Still plugging away at the tutorials, Dan's book, and the Rev docs. I 
also read Richard's Scripting Style Guide (which has a lot of good 
points for any language). One thing that I've not yet pinned down is the 
conventional wisdom with regard to placement of some items--I know how 
some things *can* be done in Rev, but I'm wondering how they *should* be 
done. I am hoping that some patient souls on the list can help dispel my 
ignorance :-[

* Functions: From what I read, a function can be called by any other 
handler in a given script. Is it therefore best to define functions at 
the beginning of a script, before any event handlers? If I want to open 
a function up to the whole application, should I define it in its own stack?

* Variables: I understand that vars are defined when they're initialised 
(except globals, which need to be declared). This upsets my sense of 
order somewhat, but I can see the advantages. That said, is it best to 
declare variables anyway? Is there any performance impact if I do or 
don't? Is it best practise to use the explicitVariables property?

* Variable type: The variable types are easy enough to distinguish, but 
I'm still getting used to Transcript, so I want to make sure I'm using 
them properly. Can someone check my work here:

(1) Local variable - accessible only within the handler that contains it 
(declare within a handler).
     on someHandler
         local intValue = 5
     end someHandler

(2) Script local variable - accessible to all handlers within the script 
that contains it (declare within a script, outside any handler).
     local intValue

     on someHandler
         intValue = 5
     end someHandler

     on someOtherHandler
         intValue = intValue * 5
     end someOtherHandler
   
(3) Global variable - accessible to all handlers in the application 
(declare in or out of a handler).
     global intValue

    -- Various handlers in various scripts that manipulate intValue

I apologise for this tedious exercise in confirmation. I'm having fun 
with Transcript, and things are working very easily, but I don't have 
any background in HyperCard, so I want to make sure that I start out 
with good scripting habits for use in the Rev world.

Cheers,

-- Erin

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