Catmandu::Logger(3pm)

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