Class/Static Constants in Delphi

Question

In Delphi, I want to be able to create an private object that\'s associated with a class, and access it from all instances of that class. In Java, I\'d use:

pub         


        

Answer 1

Here is how I'll do that using a class variable, a class procedure and an initialization block:

unit MyObject;

interface

type

TMyObject = class
   private
     class var FLogger : TLogLogger;
   public
     class procedure SetLogger(value:TLogLogger);
     class procedure FreeLogger;
   end;

implementation

class procedure TMyObject.SetLogger(value:TLogLogger);
begin
  // sanity checks here
  FLogger := Value;
end;

class procedure TMyObject.FreeLogger;
begin
  if assigned(FLogger) then 
    FLogger.Free;
end;

initialization
  TMyObject.SetLogger(TLogLogger.Create);
finalization
  TMyObject.FreeLogger;
end.