DECSTR – Decrease integer value in string

INCSTR is a C/AL command, which is often used to increase document numbers, which usually start with some letters followed by a number, e.g. AB-00010.

With INCSTR(‘AB-00010’)  you get then ‘AB-00011’.

In a Nav forum a member asked, if there is a simple way for decreasing such a document no. don’t know, why he needs that, but it’s a nice idea.

So, after a little research and finding some typical looooong c/al code solutions, i developed my own small, very cool solution using .net class Regex:

OnRun()
// loc. variables
//DocNo : Code 20

DocNo := DecStr(‘AB-00010’);
MESSAGE(DocNo);

LOCAL DecStr(DocNo : Code[20]) : Code[20]
// loc. variables
//Prefix: Text
//NoString: Text
//Number: Integer
//Regex: DotNet System.Text.RegularExpressions.Regex.’System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089′
//DotNetInt: DotNet System.Int32.’mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089′
//PadLength: Integer

Prefix := Regex.Replace(DocNo,’\d+’,”);
NoString := Regex.Match(DocNo,’\d+’).Value;
Number := DotNetInt.Parse(NoString);
IF Number > 0 THEN BEGIN
Number := Number – 1;
PadLength := STRLEN(DocNo) – STRLEN(Prefix) – STRLEN(FORMAT(Number));
EXIT(Prefix + PADSTR(”,PadLength,’0′) + FORMAT(Number));
END;

ERROR(‘Resulting number would be negative.’);

Results in: AB-00009

the resulting number has the same length.

Additional the links i found:

• http://dinukak-navmate.blogspot.co.at/2015/01/decstr-like-incstr-but-decreasing.html
• http://forum.mibuso.com/discussion/17478/decstr-like-incstr-but-decreasing