Author: Lou Adler

How to encode a HTTP URL?

Answer:

1   function HTTPEncode(const AStr: string): string;
2   const
3     NoConversion = ['A'..'Z', 'a'..'z', '*', '@', '.', '_', '-'];
4   var
5     Sp, Rp: PChar;
6   begin
7     SetLength(Result, Length(AStr) * 3);
8     Sp := PChar(AStr);
9     Rp := PChar(Result);
10    while Sp^ <> #0 do
11    begin
12      if Sp^ in NoConversion then
13        Rp^ := Sp^
14      else if Sp^ = ' ' then
15        Rp^ := '+'
16      else
17      begin
18        FormatBuf(Rp^, 3, '%%%.2x', 6, [Ord(Sp^)]);
19        Inc(Rp, 2);
20      end;
21      Inc(Rp);
22      Inc(Sp);
23    end;
24    SetLength(Result, Rp - PChar(Result));
25  end;
26  
27  procedure TForm1.Button1Click(Sender: TObject);
28  begin
29    Edit1.Text := HTTPEncode(Edit1.Text);
30  end;