Another script library question

Question

I had a quesiotn about this and "kel" gave me this suggestion:
put these in [external script file]:
property var1 : "VAR1"
property var22 : "VAR22"
property var333 : "VAR333"
then in the actual script, do:
set f to [external script file]
set s_lib to load script f
var22 of s_lib
This works but there is a problem. I have now hundreds of lines of code with almost 30 variables, occurring dozens of times in the text and to manually find each and every one of them and paste "of s_lib" after them would be just awful.
So my question is: is there a way to avoid it and simply "#include" the library somehow, like in C++?
  Mac OS X (10.4.8)  

Answer 1

Hello Asu,
I'm afraid you've missed an important point on global declaration.
The point is that the variables imported by the previous 'SCRIPT 2' become global variables in the importer script just as though they were declared as global in importer's implicit run handler. And in order to refer to those global variables from a handler other than implicit or explicit run handler, you have to declare them as global in the handler unless you have declared them as global in the top level of importer script. In this respect, the global declaration in 'handler1()' in 'SCRIPT 2' is mandatory.
Global variable declared in top level of a script and global variable declared in a handler in a script have different behaviours in regards to their scope. Please peruse the language manual for details:
cf. pp. 311-323
'Scope of Script Variables and Properties'
AppleScriptLanguageGuide.pdf
By the way, of course you may define a new variable and set it to an imported global variable, but then I think you should lose the only advantage of 'SCRIPT 2' over 'SCRIPT 1', that is no reassignments of variables are needed in 'SCRIPT 2'.
As for handlers in external script, you'd need more complicated device. See the codes below. 'SCRIPT 1A' and 'SCRIPT 2A' are revised samples for 'SCRIPT 1' and 'SCRIPT 2' respectively. Although I'm posting them here, I don't recommend this sort of coding practice at all. It unnecessarily complicates matters and makes debugging harder. I'd recommend instead the simple and natural approach in AppleScript, that is; to load an external script and to tell it to do its tasks (as kel has explained), that should minimize non-essential dependencies and maxmize modularity (in AppleScript's own fashion).
Hope this helps,
H
PS. 'run' command of AppleScript and 'run script' command in Standard Additions are utterly two things. The latter creates a new instance of script every time it is invoked and hence cannot share the context with caller script in normal means. And I see no reason to use 'run script' where I can use 'run'.
-- SCRIPT 1A
(* Import properties *)
property p1 : {} -- required if it is used in external handler with 'my' possessive. -- [*A]
property p2 : {} -- idem. -- [*A]
property pf1 : {} -- mandatory. -- [*A]
property pf11 : {} -- mandatory. -- [*A]
main()
on main()
set o to load script file "RAM Disk:test:properties.scpt" -- load external script
set {p1, p2, pf1, pf11} to o's {p1, p2, pf1, pf11}
return {p1, p2, pf1(), pf11(), handler1()}
end main
on handler1()
return {pf1(), pf11()}
end handler1
  [A] Alternatively, these properties can be declared as globals as well.
   The point is that they must not be local.
   (Also if the following code were entirely in implicit or explicit run handler,
   no declaration of properties or globals should be required, for they become implicit globals)
-- external script "properties.scpt" contains following code
on f1() -- [*1]
--return f11() -- [*2]
return pf11() -- [*3]
end f1
on f11() -- [*1]
return (my p1) + (my p2) -- [*4]
end f11
property p1 : 1
property p2 : 2
property pf1 : f1
property pf11 : f11
  [1] Handler definitions must precede the definitions of the handler name's properties.
    e.g. f1()'s definition must precede the definition of 'property pf1 : f1'.
  [2] This should fail if f1() is called (via pf1()) in a script that loads this script; e.g.
    -- code of caller
    set o to load script file "path to this script"
    set pf1 to o's pf1
    return pf1() -- this should throw error -1708
    -- end of code of caller
  [3] Always invoke other handler by its 'global' (i.e. 'property') name. cf. [2]
  [4] Possessive 'my' is required to resolve property variable properly in a handler that is
   assigned to a property by itself.
    e.g. 'my p1' is required in 'f11()' when 'p1' is a property and 'f11()' is assigned to a property.
-- end of "properties.scpt"
-- END OF SCRIPT 1A
-- SCRIPT 2A
(* Import globals *)
main()
on main()
set o to load script file "RAM Disk:test:globals.scpt" -- load external script
tell o to run
global g1, g2 -- mandatory -- [*A]
--global gf1, gf11 -- [*B]
return {{g1, g2, gf1(), gf11()}, handler1()}
end main
on handler1()
global g1, g2 -- mandatory -- [*C]
--global gf1, gf11 -- [*B]
{g1, g2, gf1(), gf11()}
end handler1
  [A] If the code currently in main() were in implicit or explicit run handler instead,
   no global declaration should be required, for the variables become implicit globals.
  [ B] Not required for 'global' handler name (that are redefined as global in 'globals.scpt').
  [C] Always required in a handler other than implicit or explicit run handler.
-- external script "globals.scpt" contains following code
global g1, g2 -- mandatory.
main()
on main()
global gf1, gf11 -- mandatory -- [*1]
set g1 to 1
set g2 to 2
set gf1 to my f1 -- [*2]
set gf11 to my f11 -- [*2]
end main
on f1()
--return f11() -- [*3]
return gf11() -- [*4]
end f1
on f11()
return g1 + g2
end f11
  [1] If the code currently in main() were in implicit or explicit run handler instead,
   no global declaration should be required for handler names, for the variables become implicit globals.
  [2] Possessive 'my' is required to resolve handler name properly in another handler.
   If the code currently in main() were in top level of script (i.e. in implicit run handler) instead,
   'my' possessive should not be required.
  [3] This should fail if f1() is called (via gf1()) in a script that loads this script; e.g.
    -- code of caller
    tell (load script file "path to this script") to run
    return gf1() -- this should throw error -1708
    -- end of code of caller
  [4] Always invoke other handler by its 'global' name. cf. [3]
-- end of "globals.scpt"
-- END OF SCRIPT 2A
  Mac OS 9.1.x