NAME

       Catmandu::Logger - A role for classes that need logging capabilities

SYNOPSIS

           package MyApp::View;
           use Moo;

           with 'Catmandu::Logger';

           sub something {
               my ($self) = @_;
               $self->log->debug("started bar"); # logs with default class catergory "MyApp::View"
               $self->log->error("started bar");
           }

DESCRIPTION

       A logging role building a very lightweight wrapper to Log::Any.  Connecting a
       Log::Any::Adapter should be performed prior to logging the first log message, otherwise
       nothing will happen, just like with Log::Any.

       The logger needs to be setup before using the logger, which could happen in the main
       application:

           package main;
           use Log::Any::Adapter;
           use Log::Log4perl;

           Log::Any::Adapter->set('Log4perl');
           Log::Log4perl::init('./log4perl.conf');

           my $app = MyApp::View->new;
           $app->something();  # will print debug and error messages

       with log4perl.conf like:

           log4perl.rootLogger=DEBUG,OUT
           log4perl.appender.OUT=Log::Log4perl::Appender::Screen
           log4perl.appender.OUT.stderr=1
           log4perl.appender.OUT.utf8=1

           log4perl.appender.OUT.layout=PatternLayout
           log4perl.appender.OUT.layout.ConversionPattern=%d [%P] - %p %l time=%r : %m%n

       See Log::Log4perl for more configuration options and selecting which messages to log and
       which not.

CATMANDU COMMAND LINE

       When using the catmandu command line, the logger can be activated using the -D option on
       all Catmandu commands:

            $ catmandu -D convert JSON to YAML < data.json
            $ catmandu -D export MongoDB --database-name items --bag

       The log4perl configuration for the "catmandu" command line must be defined in a
       'catmandu.yml' configuration file:

            $ cat catmandu.yml
            log4perl: |
              log4perl.rootLogger=DEBUG,OUT
              log4perl.appender.OUT=Log::Log4perl::Appender::Screen
              log4perl.appender.OUT.stderr=1
              log4perl.appender.OUT.utf8=1

              log4perl.appender.OUT.layout=PatternLayout
              log4perl.appender.OUT.layout.ConversionPattern=%d [%P] - %p %l time=%r : %m%n

       The "log4perl" section can point to an inline log4perl configuration or a filename
       containing the configuration.

       See Catmandu::Fix::log how to include log messages in the Catmandu::Fix language.

ACCESSORS

   log
       The "log" attribute holds the Log::Any::Adapter object that implements all logging methods
       for the defined log levels, such as "debug" or "error".

           package MyApp::View::JSON;

           extends 'MyApp::View';
           with 'Catmandu::Logger';

           sub bar {
               $self->log->info("Everything fine so far");   # logs a info message
               $self->log->debug("Something is fishy here"); # logs a debug message
           }

       Your package automatically has a logging category of MyApp::View::JSON. Use lines like:

           log4perl.logger.MyApp::View::JSON=DEBUG,STDOUT

       or

           log4perl.logger.MyApp::View=DEBUG,STDOUT

       or

           log4perl.logger.MyApp=DEBUG,STDOUT

       for specialized logging for your application.

   log_category
       Default is the class name.

SEE ALSO

       Log::Any