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

cpanm Catmandu

perl -MCPAN -e shell
install Catmandu