Oliver Gorwits

NAME

Log::Dispatch::Configurator::Any - Configurator implementation with Config::Any

VERSION

version 1.122640

PURPOSE

Use this module in combination with Log::Dispatch::Config to allow many formats of configuration file to be loaded, via the Config::Any module.

SYNOPSIS

In the traditional Log::Dispatch::Config way:

 use Log::Dispatch::Config; # loads Log::Dispatch
 use Log::Dispatch::Configurator::Any;
  
 my $config = Log::Dispatch::Configurator::Any->new('log.yml');
 Log::Dispatch::Config->configure($config);
  
 # nearby piece of code
 my $log = Log::Dispatch::Config->instance;
 $log->alert('Hello, world!');

Alternatively, without a config file on disk:

 use Log::Dispatch::Config; # loads Log::Dispatch
 use Log::Dispatch::Configurator::Any;
  
 my $confhash = {
     dispatchers => ['screen]',
     screen = {
         class => 'Log::Dispatch::Screen',
         min_level => 'debug',
     },
 };
  
 my $config = Log::Dispatch::Configurator::Any->new($confhash);
 Log::Dispatch::Config->configure($config);
  
 # nearby piece of code
 my $log = Log::Dispatch::Config->instance;
 $log->alert('Hello, world!');

DESCRIPTION

Log::Dispatch::Config is a wrapper for Log::Dispatch and provides a way to configure Log::Dispatch objects with configuration files. Somewhat like a lite version of log4j and Log::Log4perl it allows multiple log destinations. The standard configuration file format for Log::Dispatch::Config is AppConfig.

This module plugs in to Log::Dispatch::Config and allows the use of other file formats, in fact any format supported by the Config::Any module. As a bonus you can also pass in a configuration data structure instead of a file name.

USAGE

Follow the examples in the "SYNOPSIS". If you are using an external configuration file, be aware that you are required to use a filename extension (e.g. .yml for YAML).

Below are a couple of tips and tricks you may find useful.

Fall-back default config

Being able to use a configuration data structre instead of a file on disk is handy when you want to provide application defaults which the user then replaces with their own settings. For example you could have the following:

 my $defaults = {
     dispatchers => ['screen'],
     screen => {
         class     => 'Log::Dispatch::Screen',
         min_level => 'debug',
     },
 };
  
 my $config_file = '/etc/myapp_logging.conf';
 my $config = $ENV{MYAPP_LOGGING_CONFIG} || $ARGV[0] ||
     ( -e $config_file ? $config_file : $defaults);
 
 Log::Dispatch::Config->configure_and_watch(
     Log::Dispatch::Configurator::Any->new($config) );
 my $dispatcher = Log::Dispatch::Config->instance;

With the above code, your application will check for a filename in an environment variable, then a filename as a command line argument, then check for a file on disk, and finally use its built-in defaults.

Dealing with a dispatchers list

Log::Dispatch::Config requires that a global setting dispatchers have a list value (i.e. your list of dispatchers). A few config file formats do not support list values at all, or list values at the global level (two examples being Config::Tiny and Config::General).

This module allows you to have a small grace when there is only one dispatcher in use. Write the configuration file normally, and the single-item dispatchers value will automatically be promoted to a list. In other words:

 # myapp.ini
 dispatchers = screen
 
 # this becomes a config of:
 $config = { dispatchers => 'screen', ... };
 
 # so this module promotes it to:
 $config = { dispatchers => ['screen'], ... };

If you want more than one dispatcher, you then need to use a config file format which supports these lists natively, I'm afraid. A good suggestion might be YAML.

THANKS

My thanks to miyagawa for writing Log::Dispatch::Config, from where I also took some tests. Also thanks to Florian Merges for his YAML Configurator, which was a useful example and saved me much time.

AUTHOR

Oliver Gorwits <oliver@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2012 by University of Oxford.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.




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