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CGI::Application::PlugUserLContributedCPI::Application::Plugin::LogDispatch(3)

NAME
       CGI::Application::Plugin::LogDispatch - Add Log::Dispatch support to
       CGI::Application

SYNOPSIS
	package	My::App;

	use CGI::Application::Plugin::LogDispatch;

	sub cgiapp_init	{
	  my $self = shift;

	  # calling log_config is optional as
	  # some simple	defaults will be used
	  $self->log_config(
	    LOG_DISPATCH_MODULES => [
	      {	   module => 'Log::Dispatch::File',
		     name => 'debug',
		 filename => '/tmp/debug.log',
		min_level => 'debug',
	      },
	    ]
	  );
	}

	sub myrunmode {
	  my $self = shift;

	  $self->log->info('Information	message');
	  $self->log->debug('Debug message');
	}

	- or as	a class	based singleton	-

	package	My::App;

	use CGI::Application::Plugin::LogDispatch (
	  LOG_DISPATCH_MODULES => [
	    {	 module	=> 'Log::Dispatch::File',
		   name	=> 'debug',
	       filename	=> '/tmp/debug.log',
	      min_level	=> 'debug',
	    },
	  ]
	);

	My::App->log->info('Information	message');

	sub myrunmode {
	  my $self = shift;

	  $self->log->info('This also works');
	}

DESCRIPTION
       CGI::Application::Plugin::LogDispatch adds logging support to your
       CGI::Application	modules	by providing a Log::Dispatch dispatcher	object
       that is accessible from anywhere	in the application.

       If you have CGI::Application::Plugin::DevPopup installed, a "Log
       Entries"	report is added	to the popup window, containing	all of the
       entries that were logged	during the execution of	the runmode.

METHODS
   log
       This method will	return the current Log::Dispatch dispatcher object.
       The Log::Dispatch object	is created on the first	call to	this method,
       and any subsequent calls	will return the	same object.  This effectively
       creates a singleton log dispatcher for the duration of the request.  If
       "log_config" has	not been called	before the first call to "log",	then
       it will choose some sane	defaults to create the dispatcher object (the
       exact default values are	defined	below).

	 # retrieve the	log object
	 my $log = $self->log;
	 $log->warning("something's not	right!");
	 $log->emergency("It's all gone	pear shaped!");

	 - or -

	 # use the log object directly
	 $self->log->debug(Data::Dumper::Dumper(\%hash));

	 - or -

	 # if you configured it	as a singleton
	 My::App->log->debug('This works too');

   log_config
       This method can be used to customize the	functionality of the
       CGI::Application::Plugin::LogDispatch module.  Calling this method does
       not mean	that a new Log::Dispatch object	will be	immediately created.
       The log object will not be created until	the first call to $self->log.

       The recommended place to	call "log_config" is in	the "cgiapp_init"
       stage of	CGI::Application.  If this method is called after the log
       object has already been accessed, then it will die with an error
       message.

       If this method is not called at all then	a reasonable set of defaults
       will be used (the exact default values are defined below).

       The following parameters	are accepted:

       LOG_DISPATCH_OPTIONS
	   This	allows you to customize	how the	Log::Dispatch object is
	   created by providing	a hash of options that will be passed to the
	   Log::Dispatch constructor.  Please see the documentation for
	   Log::Dispatch for the exact syntax of the parameters.  Surprisingly
	   enough you will usually not need to use this	option,	instead	look
	   at the LOG_DISPATCH_MODULES option.

	    LOG_DISPATCH_OPTIONS => {
		 callbacks => sub { my %h = @_;	return time().': '.$h{message};	},
	    }

       LOG_DISPATCH_MODULES
	   This	option allows you to specify the Log::Dispatch::* modules that
	   you wish to use to log messages.  You can list multiple dispatch
	   modules, each with their own	set of options.	 Format	the options in
	   an array of hashes, where each hash contains	the options for	the
	   Log::Dispatch:: module you are configuring and also include a
	   'module' parameter containing the name of the dispatch module.  See
	   below for an	example.  You can also add an 'append_newline' option
	   to automatically append a newline to	each log entry for this
	   dispatch module (this option	is not needed if you already specified
	   the APPEND_NEWLINE option listed below which	will add a newline for
	   all dispatch	modules).

	    LOG_DISPATCH_MODULES => [
	      {		module => 'Log::Dispatch::File',
			  name => 'messages',
		      filename => '/tmp/messages.log',
		     min_level => 'info',
		append_newline => 1
	      },
	      {		module => 'Log::Dispatch::Email::MailSend',
			  name => 'email',
			    to => [ qw(foo@bar.com bar@baz.org ) ],
			subject	=> 'Oh No!!!!!!!!!!',
		     min_level => 'emerg'
	      }
	    ]

       APPEND_NEWLINE
	   By default Log::Dispatch does not append a newline to the end of
	   the log messages.  By setting this option to	a true value, a
	   newline character will automatically	be added to the	end of the log
	   message.

	    APPEND_NEWLINE => 1

       LOG_METHOD_EXECUTION (EXPERIMENTAL)
	   This	option will allow you to log the execution path	of your
	   program.  Set LOG_METHOD_EXECUTION to a list	of all the modules you
	   want	to be logged.  This will automatically send a debug message at
	   the start and end of	each method/function that is called in the
	   modules you listed.	The parameters passed, and the return value
	   will	also be	logged.	 This can be useful by tracing the program
	   flow	in the logfile without having to resort	to the debugger.

	    LOG_METHOD_EXECUTION => [qw(__PACKAGE__ CGI::Application CGI)],

	   WARNING:  This hasn't been heavily tested, although it seems	to
	   work	fine for me.  Also, a closure is created around	the log
	   object, so some care	may need to be taken when using	this in	a
	   persistent environment like mod_perl.  This feature depends on the
	   Sub::WrapPackages module.

   DEFAULT OPTIONS
       The following example shows what	options	are set	by default (ie this is
       what you	would get if you do not	call log_config).  A single
       Log::Dispatch::Screen module that writes	error messages to STDERR with
       a minimum log level of debug.

	$self->log_config(
	  LOG_DISPATCH_MODULES => [
	    {	     module => 'Log::Dispatch::Screen',
		       name => 'screen',
		     stderr => 1,
		  min_level => 'debug',
	     append_newline => 1
	    }
	  ],
	);

       Here is a more customized example that uses two file appenders, and an
       email gateway.  Here all	debug messages are sent	to /tmp/debug.log, and
       all messages above are sent to /tmp/messages.log.  Also,	any emergency
       messages	are emailed to foo@bar.com and bar@baz.org.

	$self->log_config(
	  LOG_DISPATCH_MODULES => [
	    {	 module	=> 'Log::Dispatch::File',
		   name	=> 'debug',
	       filename	=> '/tmp/debug.log',
	      min_level	=> 'debug',
	      max_level	=> 'debug'
	    },
	    {	 module	=> 'Log::Dispatch::File',
		   name	=> 'messages',
	       filename	=> '/tmp/messages.log',
	      min_level	=> 'info'
	    },
	    {	 module	=> 'Log::Dispatch::Email::MailSend',
		   name	=> 'email',
		     to	=> [ qw(foo@bar.com bar@baz.org	) ],
		 subject => 'Oh	No!!!!!!!!!!',
	      min_level	=> 'emerg'
	    }
	  ],
	  APPEND_NEWLINE => 1,
	);

EXAMPLE
       In a CGI::Application module:

	 # configure the log modules once during the init stage
	 sub cgiapp_init {
	   my $self = shift;

	   # Configure the session
	   $self->log_config(
	     LOG_DISPATCH_MODULES => [
	       {    module => 'Log::Dispatch::File',
		      name => 'messages',
		  filename => '/tmp/messages.log',
		 min_level => 'error'
	       },
	       {    module => 'Log::Dispatch::Email::MailSend',
		      name => 'email',
			to => [	qw(foo@bar.com bar@baz.org ) ],
		    subject => 'Oh No!!!!!!!!!!',
		 min_level => 'emerg'
	       }
	     ],
	     APPEND_NEWLINE => 1,
	   );

	 }

	 sub cgiapp_prerun {
	   my $self = shift;

	   $self->log->debug("Current runmode:	".$self->get_current_runmode);
	 }

	 sub my_runmode	{
	   my $self = shift;
	   my $log  = $self->log;

	   if ($ENV{'REMOTE_USER'}) {
	     $log->info("user ".$ENV{'REMOTE_USER'});
	   }

	   # etc...
	 }

SINGLETON SUPPORT
       This module can be used as a singleton object.  This means that when
       the object is created, it will remain accessable	for the	duration of
       the process.  This can be useful	in persistent environments like
       mod_perl	and PersistentPerl, since the object only has to be created
       one time, and will remain in memory across multiple requests.  It can
       also be useful if you want to setup a DIE handler, or WARN handler,
       since you will not have access to the $self object.

       To use this module as a singleton you need to provide all configuration
       parameters as options to	the use	statement.  The	use statement will
       accept all the same parameters that the log_config method accepts, so
       see the documentation above for more details.

       When creating the singleton, the	log object will	be saved in the
       namespace of the	module that created it.	 The singleton will also be
       inherited by any	subclasses of this module.

       NOTE:  Singleton	support	requires the Class::ISA	module which is	not
       installed automatically by this module.

SINGLETON EXAMPLE
	 package My::App;

	 use base qw(CGI::Application);
	 use CGI::Application::Plugin::LogDispatch(
	     LOG_DISPATCH_MODULES => [
	       {    module => 'Log::Dispatch::File',
		      name => 'messages',
		  filename => '/tmp/messages.log',
		 min_level => 'error'
	       },
	     ],
	     APPEND_NEWLINE => 1,
	   );

	 }

	 sub cgiapp_prerun {
	   my $self = shift;

	   $self->log->debug("Current runmode:	".$self->get_current_runmode);
	 }

	 sub my_runmode	{
	   my $self = shift;
	   my $log  = $self->log;

	   if ($ENV{'REMOTE_USER'}) {
	     $log->info("user ".$ENV{'REMOTE_USER'});
	   }

	   # etc...
	 }

	 package My::App::Subclass;

	 use base qw(My::App);

	 # Setup a die handler that uses the logger
	 $SIG{__DIE__} = sub { My::App::Subclass->log->emerg(@_); CORE::die(@_); };

	 sub my_other_runmode {
	   my $self = shift;

	   $self->log->info("This will log to the logger configured in My::App");
	 }

BUGS
       Please report any bugs or feature requests to
       "bug-cgi-application-plugin-logdispatch@rt.cpan.org", or	through	the
       web interface at	<http://rt.cpan.org>.  I will be notified, and then
       you'll automatically be notified	of progress on your bug	as I make
       changes.

SEE ALSO
       CGI::Application, Log::Dispatch,	Log::Dispatch::Screen,
       Sub::WrapPackages, perl(1)

AUTHOR
       Cees Hek	<ceeshek@gmail.com>

LICENSE
       Copyright (C) 2004 Cees Hek <ceeshek@gmail.com>

       This library is free software. You can modify and or distribute it
       under the same terms as Perl itself.

perl v5.32.0			  2020CGI::Application::Plugin::LogDispatch(3)

NAME | SYNOPSIS | DESCRIPTION | METHODS | EXAMPLE | SINGLETON SUPPORT | SINGLETON EXAMPLE | BUGS | SEE ALSO | AUTHOR | LICENSE

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