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LoggerPro for Delphi

An modern and pluggable logging framework for Delphi


LoggerPro is compatibile with

  • Delphi 11 Alexandria
  • Delphi 10.4 Sydney
  • Delphi 10.3 Rio
  • Delphi 10.2 Tokyo (Added Linux compatibility)
  • Delphi 10.1 Berlin
  • Delphi 10 Seattle
  • Delphi XE8
  • Delphi XE7
  • Delphi XE6
  • Delphi XE5
  • Delphi XE4
  • Delphi XE3
  • Delphi XE2

What's new in 1.4.0

  • Improved VCL and FMX visual appenders
  • Appenders can be added and removed programmatically
  • Added packages for latest versions of Delphi
  • Improved algorithm used to handle slow consumers
  • Added DMSContainer's EventStreams Appender
  • Added very basic console appender that assumes is running from console in order to provide simple Linux console logging
  • FIX Issue 50
  • New filtering log file appender that allows to pick individual tags to be written into a file.
  • FIX Issue 57
  • FIX Issue 60

What's new in 1.3.2

  • Added support for Android API level 26 in mobile demo
  • Added packages for Delphi 10.3 Rio, Delphi 10.2 Tokyo, Delphi 10.1 Berlin and Delphi 10.0 Seattle.
  • Added packages for Delphi XE7 and Delphi XE8 (these packages do not contain appenders which uses System.Net.HttpClient)
  • Added support for Linux in TLoggerProFileAppender (Thank you charoit)

What's new in 1.3.0

  • Replace TThreadedList<T> with a custom implementation (TThreadSafeQueue<T>) because of a bug and this in TMonitor.
    • TThreadSafeQueue<T> is not a drop-in replacement for the TThreadedQueue<T> but can be used in other projects if you are fighting with the same bug.
  • TVCLMemoLogAppender.Create gots new parameter: aClearOnStartup which optionally clear the memo at the startup.
  • Improvement to the TLoggerProConsoleAppender (Thanks to Fulgan)
  • Improvement to the TLoggerProFileAppender; now there is a OnLogRow callback that can be used to customize log row format.
  • New overloaded Log methods. The *Fmt versions are deprecated and will be removed in a future version ISSUE #17
  • New NSQ appender (Thanks to Fulgan)
  • New logger filter decorator (Thanks to Fulgan)
  • New REST appender with support for extended information (samples for Windows and Android)
    • Extended information are supported in Windows (fully) and Android (partially)
    • In the sample folder is provided also the RESTLogCollector
  • New Elastic Search Log appender (Thanks to Salvatore Sparacino)

Getting started

program getting_started_console;


  LoggerPro.GlobalLogger; //this is the global logger, it is perfect to understand the basic operation of LoggerPro.

    //the global logger uses a TLoggerProFileAppender, so your logs will be written on a 
    //set of files with automatic rolling/rotating
    Log.Debug('Debug message', 'main'); //TLoggerProFileAppender uses the "tag" to select a different log file	
    Log.Info('Info message', 'main');
    Log.Warn('Warning message', 'main');
    Log.Error('Error message', 'errors');
    WriteLn('Check "getting_started_console.00.main.log" and "getting_started_console.00.errors.log" to see your logs');
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);


The most flexible/correct approach is not much complicated than the global logger one. Check how is simple to create a custom instance of logwriter

program getting_started_console_appenders;


  LoggerPro, //LoggerPro core
  LoggerPro.FileAppender, //File appender
  LoggerPro.OutputDebugStringAppender; //OutputDebugString appender

  Log: ILogWriter;

  Log := BuildLogWriter([TLoggerProFileAppender.Create,

    Log.Debug('Debug message', 'main');
    Log.Info('Info message', 'main');
    Log.Warn('Warning message', 'main');
    Log.Error('Error message', 'errors');
    WriteLn('Check ');
    WriteLn('  "getting_started_console.00.main.log"');
    WriteLn('  "getting_started_console.00.errors.log"');

    if DebugHook <> 0 then //inform the user where his/her logs are
      WriteLn('also, you logs have been sent to the current debugger, check the Delphi''s EventLog window to see them.');
      WriteLn('..seems that no debugger is present. The logs can be seen using DebugView.');
      WriteLn('Download it from here');
      WriteLn('Learn how to use');
    on E: Exception do
      WriteLn(E.ClassName, ': ', E.Message);


Built-in log appenders

The framework contains the following built-in log appenders

  • File appender (TLoggerProFileAppender) (v1.0.0+)
  • Console appender (TLoggerProConsoleAppender) (v1.0.0+)
  • OutputDebugString appender (TLoggerProOutputDebugStringAppender) (v1.0.0+)
  • VCL Memo appender (TVCLMemoLogAppender) (v1.0.0+)
  • VCL ListView appender (TVCLMemoLogAppender) -- thanks to (v1.3.0+)
  • Redis Appender with LogsViewer(to aggregate logs from different instances on a single Redis instance) (v1.2.0+)
  • Email appender (to send email as log, very useful for fatal errors) (v1.2.0+)
  • SysLog appender RFC 5424 compliant -- thanks to (v1.3.0+)
  • NSQ appender (Thanks to Fulgan) (v1.3.0+)
  • Decorator appender (Thanks to Fulgan) (v1.3.0+)

Next appenders in the development pipeline

  • RESTful Appender (to send logs to a rest endpoint using a specific request format, so that you can implement log server in DelphiMVCFramework, PHP, Java, Python, Node etc)
  • Twitter Appender (to send logs to a Twitter Account)
  • Database appender (to send logs to a database table using FireDAC components -- Thank You Omar Bossoni)

The log writers and all the appenders are asycnhronous.

Check the samples to see how to use each appender or even combine different appenders.


Documentation is available in the docs folder as HTML.


You can install Delphinus package manager and install LoggerPro as a package there. (Delphinus-Support)