program OOP_design;

//example with objects and exception handling
//open a file, add a line, save to another file, show the result on the screen
//solution to pas_oodesign5.txt
//shows with .loadFromFile polymorphie 
//add a second parameter file 'filename' at last in getFiletoStr(); loc's=57


function getFiletoStr(strObj: TStringList): TStringList;
begin 
  //strObj.loadfromfile()
  result:= strObj;
  with result do begin
    clear;
    loadFromFile('firstdemo.txt');
  end
end;


procedure showFileonMemo(myfile: string);
var
  Mst: TMemoryStream;
begin
  Mst:= TMemoryStream.Create;
  try
    Mst.LoadFromFile(myfile);
    Mst.Seek(0,0);
    Memo2.Lines.LoadFromStream(Mst);      
  finally
    Mst.Free;
  end;
end;



//main topic
begin
  //constructor
  with getFileToStr(TStringList.create) do begin
  //myFileStr:= getFileToStr(myFilestr);
    add('new line in list');
    SaveToFile('firstdemo2.txt')
    showFileonMemo('firstdemo2.txt');
  //destructor
    Free;
  end  
end.


         ____    ___   _      ____    _   _   _
        |  _ \  |  _| | |    |  _ \  | | | | | |
        | | . | | |_  | |    | |_| | | |_| | | |
        | | | | |  _| | |    |  __/  |  _  | | |          
        | |_. | | |_  | |__  | |     | | | | | |                      
        |____/  |___| |____| |_|     |_| |_| |_|