Optional Parameters For 'func' ?

[piccaso]

So i wrote a little function to find 'free' temp Filenames

func FileTempName ($dir,$ext)
  if $dir == "" Then $dir = @TempDir
  if FileExists($dir) == 0 Then $dir = @TempDir
  if StringRight($dir,1) <> '\' Then $dir = $dir & '\'
  if $ext == "" Then $ext="tmp"
  $timestamp = TimerStart()
     do
    $tempfile = filegetshortname($dir&Int(Random(10000000,99999999))&"."&$ext)
    if TimerStop($timestamp) > 2500 Then
    seterror(1)
    Return
    endif
     until FileExists($tempfile) == 0
  Return $tempfile
endfunc

and i want $dir and $ext to be optional.

is this possible?

[pekster]

No, but you could pass an array to the function. Then do some array checking to see how many optional paramaters have been passed through the array. Something like

Func OptionalParams($required, $required2, $optional)
  If UBound($optional) = 2 Then;2 vars passed through optional array
  ;do stuff
  ElseIf UBound($optional) = 0 Then;no vars passed through array
  ;do other stuff
  Else;general clause to catch bad input
  ;quit with some error message about bad paramaters
  EndIf
EndFunc

Edited to correct a typo in the code

Edited May 17, 2004 by pekster

[CyberSlug]

Optional paramters is a feature being discussed.

Antother workaround is to use a single string parameter where variables are separated by a the pipe "|" symbol. I use pipe here since it is never allow in file names or paths.

func FileTempName ($pipeSeparatedParams)
   Local $dir = "", $ext = "", $timestamp, $tempfile
   Local $params = StringSplit($pipeSeparatedParams, "|")
   If IsArray($params)Then
      If 1 = $params[0]  Then $dir = $params[1]
      If 2 = $params[0]  Then $ext = $params[2]
   EndIf
; rest of your code goes here

P.S. You might consider using FileFindNextFile.

Edited May 17, 2004 by CyberSlug

[piccaso]

Still the goal remains unreachable...

But i can call it by using FileTempName('','') anyway

why shuld i consider using FileFindNextFile ?

i dont get the point here

thx for the nice support ( i think i will have to put this in my sig )

[trids]

Still the goal remains unreachable...

Sluggie's pipe-delimited parameter list is a very sound workaround to simulate optional parameters

[piccaso]

you cant call the function without parameters -> Nothing inside the brackets, and this was my goal.

Of corse The mentioned pipe workaround is a great idea

[pekster]

Having the paramater be empty is not really that big of a problem. You could always do 'Function(0)' and have the function first test for a string (and exit if it doesn't get one, or whatever you need it to.) As long as you know that your function treats a non-string as no paramater it will work fine. Or use a blank string 'Function("")'. No need for the comma in your above example.