How do I pretty-print JSON in Delphi?

Question

I am looking for a function that will take a string of JSON as input and format it with line breaks and indentations (tabs).

Example: I have input line:

Answer 1

This is a bit old, but if anyone is interested Delphi's native System.JSON unit can do this too. Sample uses a TMemo and a TButton to format the JSON

procedure TForm1.btnFormatJSONClick(Sender: TObject);
const
 DEF_INDENT = 2;
var
 JO : TJSONObject;
begin
 try
  JO := TJSONObject.ParseJSONValue(memoJSON.Text) as TJSONObject;
  memoJSON.Text := JO.Format(DEF_INDENT);
 except
  on E:Exception do
   begin
    MessageDlg('Error in JSON syntax', mtError, [mbOK], 0);
   end;
 end;
end;