log::log4perl::catalyst(3pm) [debian man page]

Catalyst(3pm)						User Contributed Perl Documentation					     Catalyst(3pm)

NAME

       Log::Log4perl::Catalyst - Log::Log4perl Catalyst Module

SYNOPSIS

       In your main Catalyst application module:

	 use Log::Log4perl::Catalyst;

	   # Either make Log4perl act like the Catalyst default logger:
	 __PACKAGE__->log(Log::Log4perl::Catalyst->new());

	   # or use a Log4perl configuration file, utilizing the full
	   # functionality of Log4perl
	 __PACKAGE__->log(Log::Log4perl::Catalyst->new('l4p.conf'));

       ... and then sprinkly logging statements all over any code executed by Catalyst:

	   $c->log->debug("This is using log4perl!");

DESCRIPTION

       This module provides Log4perl functions to Catalyst applications. It was inspired by Catalyst::Log::Log4perl on CPAN, but has been
       completely rewritten and uses a different approach to unite Catalyst and Log4perl.

       Log4perl provides loggers, usually associated with the current package, which can then be remote-controlled by a central configuration.
       This means that if you have a controller function like

	   package MyApp::Controller::User;

	   sub add : Chained('base'): PathPart('add'): Args(0) {
	       my ( $self, $c ) = @_;

	       $c->log->info("Adding a user");
	       # ...
	   }

       Level-based control is available via the following methods:

	  $c->log->debug("Reading configuration");
	  $c->log->info("Adding a user");
	  $c->log->warn("Can't read configuration ($!)");
	  $c->log->error("Can't add user ", $user);
	  $c->log->fatal("Database down, aborting request");

       But that's no all, Log4perl is much more powerful.

       The logging statement can be suppressed or activated based on a Log4perl file that looks like

	     # All MyApp loggers opened up for DEBUG and above
	   log4perl.logger.MyApp = DEBUG, Screen
	   # ...

       or

	     # All loggers block messages below INFO
	   log4perl.logger=INFO, Screen
	   # ...

       respectively. See the Log4perl manpage on how to perform fine-grained log-level and location filtering, and how to forward messages not
       only to the screen or to log files, but also to databases, email appenders, and much more.

       Also, you can vary the layout of each message. For example if you want to know where a particular statement was logged, turn on file names
       and line numbers:

	   # Log4perl configuration file
	   # ...
	   log4perl.appender.Screen.layout.ConversionPattern = 
		 %F{1}-%L: %p %m%n

       Messages will then look like

	   MyApp.pm-1869: INFO Saving user profile for user "wonko"

       Or want to log a request's IP address with every log statement? No problem with Log4perl, just call

	   Log::Log4perl::MDC->put( "ip", $c->req->address() );

       at the beginning of the request cycle and use

	   # Log4perl configuration file
	   # ...
	   log4perl.appender.Screen.layout.ConversionPattern = 
		 [%d]-%X{ip} %F{1}-%L: %p %m%n

       as a Log4perl layout. Messages will look like

	   [2010/02/22 23:25:55]-123.122.108.10 MyApp.pm-1953: INFO Reading profile for user "wonko"

       Again, check the Log4perl manual page, there's a plethora of configuration options.

METHODS

       new($config, [%options])
	   If called without parameters, new() initializes Log4perl in a way so that messages are logged similiarly to Catalyst's default logging
	   mechanism. If you provide configuration, either the name of a configuration file or a reference to scalar string containing the
	   configuration, it will call Log4perl with these parameters.

	   The second (optional) parameter is a list of key/value pairs:

	     'autoflush'   =>  1   # Log without buffering ('abort' not supported)
	     'watch_delay' => 30   # If set, use L<Log::Log4perl>'s init_and_watch

       _flush()
	   Flushes the cache.

       abort($abort)
	   Clears the logging system's internal buffers without logging anything.

   Using :easy Macros with Catalyst
       If you're tired of typing

	   $c->log->debug("...");

       and would prefer to use Log4perl's convenient :easy mode macros like

	   DEBUG "...";

       then just pull those macros in via Log::Log4perl's :easy mode and start cranking:

	   use Log::Log4perl qw(:easy);

	     # ... use macros later on
	   sub base :Chained('/') :PathPart('apples') :CaptureArgs(0) {
	       my ( $self, $c ) = @_;

	       DEBUG "Handling apples";
	   }

       Note the difference between Log4perl's initialization in Catalyst, which uses the Catalyst-specific Log::Log4perl::Catalyst module (top of
       this page), and making use of Log4perl's loggers with the standard Log::Log4perl loggers and macros. While initialization requires Log4perl
       to perform dark magic to conform to Catalyst's different logging strategy, obtaining Log4perl's logger objects or calling its macros are
       unchanged.

       Instead of using Catalyst's way of referencing the "context" object $c to obtain logger references via its log() method, you can just as
       well use Log4perl's get_logger() or macros to access Log4perl's logger singletons.  The result is the same.

COPYRIGHT AND LICENSE

       Copyright 2002-2010 by Mike Schilli <m@perlmeister.com>

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.10.1							    2010-07-21							     Catalyst(3pm)