Good, free Delphi logging framework

Question

can anybody hint me a good, free Delphi logging framework? It should be easy to use and it should support different "log writers" including plain text, database and network.

Answer 1

Which logging library is better? mentions the following of which only the last two are free.

• CodeSite
• SmartInspect
• Log4Delphi
• TraceFormat

Answer 2

I know it's not free - but well worth it's money: CodeSite by Raize Software. Quality has its price! :-)

I always enjoyed working with CodeSite, especially the ability to add just about any type of objects to the log without huge conversions to a string format was often very helpful.

Again: not free, but worth its price in gold, if you really are serious about production-quality logging and viewing of those logs.

Marc

Answer 3

I have been granted access to update the dormant Log4Delphi project and I have rolled up 4 years of bugfixes and patches into the latest 0.8 release available on Source-forge. I use this library in production and have found it to very stable and reliable and easy to use.

Log4Delphi Downloads Page

Answer 4

There is Log4D, another port of the Java Log4J logging framework for Delphi at Sourceforge.

Log4D project page at sourceforge

A description of its architecture can be found on CodeCentral and here.

Help files are available online at http://cc.embarcadero.com/item/16446.

It is currently based on log4j 1.2.12 and quite active, and very easy to use. It includes TLogODSAppender, TLogStreamAppender, TLogFileAppender, TLogRollingFileAppender.

The following example project creates a ODS appender. If you run it in the IDE, the log messages will appear in the ‘Event log’ window.

program Log4Dexample;

{$APPTYPE CONSOLE}

uses
  Log4D,
  SysUtils;

var
  Logger: TLogLogger;

begin
  try
    // basic configuration - creates a TLogODSAppender (ODS = OutputDebugString)
    TLogBasicConfigurator.Configure;

    // set the log level
    TLogLogger.GetRootLogger.Level := Trace;

    // create a named logger
    Logger := TLogLogger.GetLogger('exampleLogger');

    // write log messages
    Logger.Fatal('fatal output');
    Logger.Error('error output');
    Logger.Warn('warn output');
    Logger.Info('info output');
    Logger.Debug('debug output');
    Logger.Trace('trace output');

    ReadLn;

  except
    on E:Exception do
    begin
      Writeln(E.Classname, ': ', E.Message);
      ReadLn;
    end;
  end;
end.

Writing appenders is straightforward, here is an example of a simple console appender:

unit LogConsoleAppender;

interface

uses
  Log4D;

type
  { Send log messages to console output. }
  TLogConsoleAppender = class(TLogCustomAppender)
  protected
    procedure DoAppend(const Message: string); override;
  end;

implementation

{ TLogConsoleAppender }

procedure TLogConsoleAppender.DoAppend(const Message: string);
begin
  if IsConsole then
    Write(Message);
end;

initialization
  RegisterAppender(TLogConsoleAppender);

end.

Answer 5

There is another new logging framework for Delphi, which comes in a single file (nxlogging.pas). nxlogging is a nice lightweight and powerful set of classes like log4d (appenders, formaters), but much easier tu use. It includes file appenders (rolling files, all in a single one, etc...) and a tcp appender too, so you can forward your logs to a central logserver.

Answer 6

Another alternative to Codesite is Overseer which is open sourced and part of the nexus project, but stands alone so does not require you to use their framework.