TrimUtf16String

Short summary

This function removes whitespace both from the start and the end of a utf-16 string. It returns the string length in words.

Example:

myString :WString(10) := " Test " ;
newLength :UDINT;
------------------
TrimUtf16String(
	stringAddress := ADR(myString),
	newStringLength => newLength
);

• Return type: UDINT

Parameters

Name	Type	Comment	Kind
stringAddress	POINTER TO WORD	pointer to the utf-16 string	input
newStringLength	UDINT	new length of the string in words	output

Code

Declaration

FUNCTION TrimUtf16String :UDINT
VAR_INPUT
	(*pointer to the utf-16 string*)
	stringAddress	:POINTER TO WORD;
END_VAR
VAR_OUTPUT
	(* new length of the string in words *)
	newStringLength :UDINT := 0;
END_VAR
VAR
	stringLength :UDINT;
	codepoints :POINTER TO UnicodeCodePoint;
	codepointCount :UDINT;
END_VAR

Implementation

stringLength := GetUtf16StringLength(stringAddress);
newStringLength := 0;
TrimUtf16String := 0;
RETURN((stringAddress = 0) OR_ELSE (stringLength = 0));
codepoints := __NEW(UnicodeCodepoint, stringLength);
RETURN(codepoints = 0);

GetCodepointsFromUtf16String(
	utf16StringAddress := stringAddress,
	utf16StringWordCount := stringLength,
	codepointBuffer := codepoints,
	bufferSize := stringLength*SIZEOF(UnicodeCodepoint),
	codePointCount => codepointCount
);	

TrimCodepoints(
	codepoints := codepoints,
	codepointCount := codepointCount,
	newCodepointCount => codepointCount
);

Tc2_System.MEMSET(stringAddress, 0, stringLength*2);

GetUtf16StringFromCodepoints(
	addressOfCodePoints := codepoints,
	codePointCount := codepointCount,
	stringBuffer := stringAddress,
	bufferSize := (stringLength + 1)*SIZEOF(WORD), // stringlength + NULL terminator
	utf16StringWordCount => newStringLength
);

TrimUtf16String := newStringLength;
__DELETE(codepoints);