Jump in Script from bottom to top and vice versa?

Scripting Forums AppleScript | Mac OS X
#1

Hi Folks,

is it possible to jump in a script file?

f.ex:

something like

if … then goto to …

else if then goto …

end if

Thanks for your reply!

Best regards,

Stefan

#2

Hi Stefan,

no, it isn’t, but there is always a way to work around e.g. with a handler

if x is 1 then
goto1(x)
else if x is 2 then
goto2(x)
end if

but it is no way to go to a certain line of a script (like the goto command in Basic)

#3

Hi Stefan,

thanks - but how can I catch the handler? How can I get it?

Thanks for your help,

Stefan

#4

write it! :slight_smile:

Handlers are a great option to extend the language in the way you want.

Another way is to work with flags to skip parts of the code if necessary.

#5

Hi Stefan,

thanks for your hint, but I am not quite sure how the syntax should look like…


get handle_pin()

on handle_pin

end handle_pin

is this correct?

Thanks for your help…

Stefan

#6

Perhaps a better explanation of what you are trying to do would help… but here’s an example

set persons_name to "Jay" -- other value you could set to would be Bob
if persons_name is equal to "Jay" then
	welcome_Jay()
else
	welcome_Bob()
end if

on welcome_Jay()
	display dialog "Hi Jay"
end welcome_Jay

on welcome_Bob()
	display dialog "Hi Bob"
end welcome_Bob

But you can pass handlers (think of them as subroutines) other values so a better idea would be to do it like this

set persons_name to "Jay" -- other value you could set to would be Bob
welcome(persons_name)

on welcome(theName)
	display dialog "Hi " & theName
end welcome

The nice thing about handlers is they can return values so lets go a tad farther…

set persons_name to "Jay" -- other value you could set to would be Bob
set persons_age to welcome(persons_name)
display dialog "Hi " & persons_name & ", so I hear you are " & persons_age

on welcome(theName)
	if theName is "Jay" then
		return "28"
	else
		return "33"
	end if
end welcome
#7

Hi James,

thanks a lot for your feedback - it helps a lot…!

Best regards,

Stefan

#8

Nicely done, James.

In addition, MacScripter.net/unScripted has a bunch of articles on Handlers:

By TJ Mahaffey: Script Handlers

and a series of three (parts 1, 2, and 3) by Ben Waldie:
Getting Started with Handlers (Part 1 of a 3-part Tutorial),
Getting Started with Handlers (Part 2 of a 3-part Tutorial),
Getting Started with Handlers (Part 3 of a 3-part Tutorial)

I might add as a later edit, that the use of GoTo in programming languages (particularly the BASIC language) was considered a very bad thing by most computer scientists because it makes the code almost impossible to debug - it is very hard to keep track of where the code has gone. It was, and still is, strongly advised to use functions and subroutines (which in AppleScript are handlers), or to use what were called “Case” statements (in AppleScript, they go as shown below).

repeat
	set N to (text returned of (display dialog "Enter a number between 1 and 4" default answer "")) as number
	if N > 0 and N < 5 then exit repeat
end repeat
-- Now the cascade of checks (better done with a list, but this shows the structure):
if N = 1 then
	set tName to "Adam"
else if N = 2 then
	set tName to "James"
else if N = 3 then
	set tName to "Stefan"
else
	set tName to "Peter"
end if
tName
#9

Thanks Adam =) And have I mentioned how much I despise the actual lack of a case command.