Decode UTF-8 encoded Cyrillic with Delphi 2007 - delphi

Question

I am working in Delphi 2007 (no Unicode support) and I am retrieving XML and JSON data from the Google Analytics API. Below is some UTF-8 encoded data that I get for a URL referral path:
ga:referralPath=/add/%D0%9F%D0%B8%D0%B6%D0%B0%D0%BC
When I decode it using this decoder it properly generates this:
ga:referralPath=/add/Пижам
Is there a function I can use in Delphi 2007 which will perform this decoding?
UPDATE
This data is corresponds to a URL. Ultimately what I want to do is to store this in a SqlServer database (out of the box - no settings modified regarding character sets). And then be able to produce/create an html pages with a working link to this page (note: I am only dealing with the url referral path in this example - obviously to make a valid url link a source would be needed).

Answer 1

D2007 supports Unicode, just not to the extent that D2009+ does. Unicode in D2007 is handled using WideString and the few RTL support functions that do exist.
The URL contains percent-encoded UTF-8 byte octets. Simply convert those sequences into their binary representation and then use UTF8Decode() to decode the UTF-8 data to a WideString. For example:
function HexToBits(C: Char): Byte;
begin
case C of
'0'..'9': Result := Byte(Ord(C) - Ord('0'));
'a'..'f': Result := Byte(10 + (Ord(C) - Ord('a')));
'A'..'F': Result := Byte(10 + (Ord(C) - Ord('A')));
else
raise Exception.Create('Invalid encoding detected');
end;
end;
var
sURL: String;
sWork: UTF8String;
C: Char;
B: Byte;
wDecoded: WideString;
I: Integer;
begin
sURL := 'ga:referralPath=/add/%D0%9F%D0%B8%D0%B6%D0%B0%D0%BC';
sWork := sURL;
I := 1;
while I <= Length(sWork) do
begin
if sWork[I] = '%' then
begin
if (I+2) > Length(sWork) then
raise Exception.Create('Incomplete encoding detected');
sWork[I] := Char((HexToBits(sWork[I+1]) shl 4) or HexToBits(sWork[I+2]));
Delete(sWork, I+1, 2);
end;
Inc(I);
end;
wDecoded := UTF8Decode(sWork);
...
end;

Answer 2

You can use the following code, which uses Windows API :
function Utf8ToStr(const Source : string) : string;
var
i, len : integer;
TmpBuf : array of byte;
begin
SetLength(Result, 0);
i := MultiByteToWideChar(CP_UTF8, 0, #Source[1], Length(Source), nil, 0);
if i = 0 then Exit;
SetLength(TmpBuf, i * SizeOf(WCHAR));
Len := MultiByteToWideChar(CP_UTF8, 0, #Source[1], Length(Source), #TmpBuf[0], i);
if Len = 0 then Exit;
i := WideCharToMultiByte(CP_ACP, 0, #TmpBuf[0], Len, nil, 0, nil, nil);
if i = 0 then Exit;
SetLength(Result, i);
i := WideCharToMultiByte(CP_ACP, 0, #TmpBuf[0], Len, #Result[1], i, nil, nil);
SetLength(Result, i);
end;