Windows-Automatisation 4

Object Rexx (“ooRexx”) vs. MS Visual Basic Script ("VBScript")

MS Visual BASIC (Script/Application) ….

Extremely popular on Windows for OLE programming
Different closely related versions
- VBS a.k.a. VBScript (Visual BASIC script)
- VBA (Visual BASIC for Applications)
Searching the Internet with the keywords "vba ole someApp/Method"
- Usually yields many hits with VBScript/VBA code snippets
- Therefore important to know how to translate VBScript/VBA <---> ooRexx
A comment on VB.NET
- Visual BASIC for .NET
- Resembles VBScript and VBA, but is not compatible

ooRexx vs. VBScript, 1

ooRexx

Message operator
~ (Tilde)
Continuation character
, (comma) or – (dash)
String concatenation
(space between strings)
|| (2 vertical bars)

var1"some string"var2 (abuttal)
Defining variables
Just denote the name in an assignment

VBScript

"Message" (dereference) operator
. (dot)
Continuation character
_ (underline)
String concatenation
& (ampersand)
Defining variables
DIM var_names

ooRexx vs. VBScript, 2

ooRexx

Line comment
-- (2 dashes)
Block (multi-line) comments
```
/* ... */
```
- May span multiple lines
- May be nested

VBScript

Line comment
' (apostroph)
```
REM
```
- Abbreviation for REMark
- No statement before it allowed
```
: REM
```
- If following a statement in the same line, must be preceeded by a column surrounded by a space

ooRexx vs. VBScript, 3

ooRexx

Calling a procedure
```
CALL proc1 a1, a2, a3
```

Calling a function

a=proc1(a1, a2, a3)

or:

CALL proc1 a1, a2, a3
a=result

VBScript

Calling a procedure

CALL proc1(a1, a2, a3)

or:
```
proc1 a1, a2, a3
```
Calling a function
```
a=proc1(a1, a2, a3)
```

ooRexx vs. VBScript, 4

ooRexx

Calling a function

a=proc1( , , a3)

or:

CALL proc1 , , a3
a=result

VBScript

Calling a function
```
a=proc1(  ,   , a3)
```
Calling a function using named arguments, e.g.
```
a=proc1( a3 := "Das 3. Argument!" )
```

ooRexx vs. VBScript, 5

ooRexx

Defining a procedure

proc1: procedure
  use arg a1, a2, a3
  say "a1="a1 "a2="a2 "a3="a3
  return

or:

::routine proc1
  use arg a1, a2, a3
  say "a1="a1 "a2="a2 "a3="a3

VBScript

Defining a procedure

Sub proc1(a1, a2, a3)
   MsgBox "a1=" & a1 & " a2=" & a2 _
          " a3=" & a3
End Sub

ooRexx vs. VBScript, 6

ooRexx

Defining a function

proc1: procedure
  use arg a1, a2, a3
  return a1 || a2 || a3

or:

::routine proc1
  use arg a1, a2, a3
  return a1 || a2 || a3

VBScript

Defining a function

Func proc1(a1, a2, a3)
   proc1=a1 & a2 & a3
End Func

ooRexx vs. VBScript, 7

ooRexx

Address structure/object:

MyLabel~Height  = 2000
MyLabel~Width   = 2000
MyLabel~Caption = "This is MyLabel"

or (to save a little bit of typing):

m=MyLabel
m~Height  = 2000
m~Width   = 2000
m~Caption = "This is MyLabel"

VBScript

Address structure/object: WITH statement

With MyLabel
   .Height  = 2000
   .Width   = 2000
   .Caption = "This is MyLabel"
End With

without WITH statement

MyLabel.Height  = 2000
MyLabel.Width   = 2000
MyLabel.Caption = "This is MyLabel"

ooRexx vs. VBScript, 8

' VBScript: "counter.vbs"
dim MyVar
Set MyVar = createObject("Some.Counter")
wscript.echo "Counter: " & MyVar.counter
call wscript.echo( "Counter: " & MyVar.increment )

-- REXX: "counter.rex"
MyVar = .OLEObject~new("Some.Counter")
wscript~echo( "Counter:" MyVar~counter )
wscript~echo( "Counter:" MyVar~increment )

Contact

WU

Prof. Mag. Dr. Rony G. Flatscher

Welthandelsplatz 1

1020 Wien/Vienna

Austria/Europe

www: www.wu.ac.at