How to make a UDF?

[Damein]

I thought it was just simple, you create a script with a function and etc. and then you create another script that calls on that function and you get the information back.

For example:

TestUDF.au3

Func _Test1()
  $Var = "String"
  $VarStripped = StringTrimLeft($Var, 1)
EndFunc

TestingUDF.au3

#include <TestUDF.au3>

HotKeySet("{1}", "_TestRun")

Func _TestRun()
  _Test1()
  MsgBox(0, "Test", $VarStripped)
EndFunc

But obviously not. I was just wondering on the proper way of making a UDF, but I could not find any documentation on it.

[GEOSoft]

That's the right principal but in all liklihood the call is incorrect.

First a UDF should have the Line

#Include-Once

at the top of it so you don't inadvertantly include it in another UDF and then call both.

Secondly, read the help file about #include. Calling it with <filename.au3> makes AutoIt look in AutoIt's include folder. You probably wanted to call it with a specific path so it should have been

#include "path\filename.au3"

That is a generalization because there is a registry hack that will tell AutoIt to also look in other specific folders when using the <> method.

[Melba23]

Damein,

You need to declare $VarStripped as a Global variable so that all the functions in your script can see it. At the moment the 2 functions each see only their Local versions of the variable which is destroyed when the function ends.

Your current script showing why it does not work:

; #include <TestUDF.au3> ; This is expanded so AutoIt sees the following lines
Func _Test1()
  $Var = "String"                        ; This variable only exists within this function
  $VarStripped = StringTrimLeft($Var, 1) ; As does this one - they are both destroyed when the function exits
EndFunc

HotKeySet("{1}", "_TestRun")

Func _TestRun()
  _Test1()
  MsgBox(0, "Test", $VarStripped) ; This variable again only exists within this function
EndFunc

I even get an error if I try to run this code telling me that the $VarStripped variable in the MsgBox line is undeclared.

You just need to add Global $VarStripped at the top of your script so that all your functions can see the variable.

Take a look at the Variables - using Global, Local and ByRef tutorial in the Wiki for a more detailed explanation of Global and Local.

M23

P.S. You do not need the {} in your HotKey declaration either!

[Bowmore]

For your example a better way would be.

TestUdf.au3

#include-once
Func _Test1($var)
  $VarStripped = StringTrimLeft($Var, 1)
    Return $VarStripped
EndFunc

Used like this

#include <TestUDF.au3>

HotKeySet("{1}", "_TestRun")
While 1

WEnd
Func _TestRun()
   $var = "String"
   $VarStripped =_Test1($var)
    MsgBox(0, "Test", $VarStripped)
 EndFunc

or alternatively like this

#include <TestUDF.au3>

HotKeySet("{1}", "_TestRun")
While 1

WEnd
Func _TestRun()
  MsgBox(0, "Test", _Test1("String"))
EndFunc

Edit: Fixed AutoIt tags

Edited April 26, 2011 by Bowmore