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Log::Contextual::WarnLogger(3) User Contributed Perl Documentation Log::Contextual::WarnLogger(3)

NAME

Log::Contextual::WarnLogger - logger for libraries using Log::Contextual

VERSION

version 0.008001

SYNOPSIS

 package My::Package;
 use Log::Contextual::WarnLogger;
 use Log::Contextual qw( :log ),
   -default_logger => Log::Contextual::WarnLogger->new({
      env_prefix => 'MY_PACKAGE',
      levels => [ qw(debug info notice warning error critical alert emergency) ],
   });
 # warns '[info] program started' if $ENV{MY_PACKAGE_TRACE} is set
 log_info { 'program started' }; # no-op because info is not in levels
 sub foo {
   # warns '[debug] entered foo' if $ENV{MY_PACKAGE_DEBUG} is set
   log_debug { 'entered foo' };
   ...
 }

DESCRIPTION

This module is a simple logger made for libraries using Log::Contextual. We recommend the use of this logger as your default logger as it is simple and useful for most users, yet users can use "set_logger" in Log::Contextual to override your choice of logger in their own code thanks to the way Log::Contextual works.

METHODS

new

Arguments: "Dict[ env_prefix => Str, levels => List ] $conf"

 my $l = Log::Contextual::WarnLogger->new({ env_prefix => 'BAR' });

or:

 my $l = Log::Contextual::WarnLogger->new({
   env_prefix => 'BAR',
   levels => [ 'level1', 'level2' ],
 });

Creates a new logger object where "env_prefix" defines what the prefix is for the environment variables that will be checked for the log levels.

The log levels may be customized, but if not defined, these are used:

For example, if "env_prefix" is set to "FREWS_PACKAGE" the following environment variables will be used:

 FREWS_PACKAGE_UPTO
 FREWS_PACKAGE_TRACE
 FREWS_PACKAGE_DEBUG
 FREWS_PACKAGE_INFO
 FREWS_PACKAGE_WARN
 FREWS_PACKAGE_ERROR
 FREWS_PACKAGE_FATAL

Note that "UPTO" is a convenience variable. If you set "FOO_UPTO=TRACE" it will enable all log levels. Similarly, if you set it to "FATAL" only fatal will be enabled.

$level

Arguments: @anything

All of the following six methods work the same. The basic pattern is:

 sub $level {
   my $self = shift;
   warn "[$level] " . join qq{\n}, @_;
      if $self->is_$level;
 }

trace

 $l->trace( 'entered method foo with args ' join q{,}, @args );

debug

 $l->debug( 'entered method foo' );

info

 $l->info( 'started process foo' );

warn

 $l->warn( 'possible misconfiguration at line 10' );

error

 $l->error( 'non-numeric user input!' );

fatal

 $l->fatal( '1 is never equal to 0!' );

If different levels are specified, appropriate functions named for your custom levels work as you expect.

Note: "fatal" does not call "die" for you, see "EXCEPTIONS AND ERROR HANDLING" in Log::Contextual

is_$level

All of the following six functions just return true if their respective environment variable is enabled.

is_trace

 say 'tracing' if $l->is_trace;

is_debug

 say 'debuging' if $l->is_debug;

is_info

 say q{info'ing} if $l->is_info;

is_warn

 say 'warning' if $l->is_warn;

is_error

 say 'erroring' if $l->is_error;

is_fatal

 say q{fatal'ing} if $l->is_fatal;

If different levels are specified, appropriate is_$level functions work as you would expect.

AUTHOR

Arthur Axel "fREW" Schmidt <frioux+cpan@gmail.com>

COPYRIGHT AND LICENSE

This software is copyright (c) 2018 by Arthur Axel "fREW" Schmidt.

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

2018-01-20 perl v5.38.2