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:

       trace
       debug
       info
       warn
       error
       fatal

       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.