NAME
MooseX::Role::Loggable - Extensive, yet simple, logging role using Log::Dispatchouli
VERSION
version 0.114
SYNOPSIS
package My::Object;
use Moose; # or Moo
with 'MooseX::Role::Loggable';
sub do_this {
my $self = shift;
$self->set_prefix('[do_this] ');
$self->log_debug('starting...');
...
$self->log_debug('more stuff');
$self->clear_prefix;
}DESCRIPTION
This is a role to provide logging ability to whoever consumes it using Log::Dispatchouli. Once you consume this role, you have attributes and methods for logging defined automatically.
package MyObject;
use Moose # Moo works too
with 'MooseX::Role::Loggable';
sub run {
my $self = shift;
$self->log('Trying to do something');
# this only gets written if debug flag is on
$self->log_debug('Some debugging output');
$self->log(
{ level => 'critical' },
'Critical log message',
);
$self->log_fatal('Log and die');
}This module uses Moo so it takes as little resources as it can by default, and can seamlessly work with both Moo or Moose.
Propagating logging definitions
Sometimes your objects create additional object which might want to log using the same settings. You can simply give them the same logger object.
package Parent;
use Moose;
with 'MooseX::Role::Loggable';
has child => (
is => 'ro',
isa => 'Child',
lazy => 1,
builder => '_build_child',
);
sub _build_child {
my $self = shift;
return Child->new( logger => $self->logger );
}ATTRIBUTES
debug
A boolean for whether you're in debugging mode or not.
Default: no.
Read-only.
logger_facility
The facility the logger would use. This is useful for syslog.
Default: local6.
logger_ident
The ident the logger would use. This is useful for syslog.
Default: calling object's class name.
Read-only.
log_to_file
A boolean that determines if the logger would log to a file.
Default location of the file is in /tmp.
Default: no.
Read-only.
log_to_stdout
A boolean that determines if the logger would log to STDOUT.
Default: no.
log_to_stderr
A boolean that determines if the logger would log to STDERR.
Default: no.
log_file
The leaf name for the log file.
Default: undef
log_path
The path for the log file.
Default: undef
log_pid
Whether to append the PID to the log filename.
Default: yes
log_fail_fatal
Whether failure to log is fatal.
Default: yes
log_muted
Whether only fatals are logged.
Default: no
log_quiet_fatal
From Log::Dispatchouli: 'stderr' or 'stdout' or an arrayref of zero, one, or both fatal log messages will not be logged to these.
Default: stderr
logger
A Log::Dispatchouli object.
METHODS
All methods here are imported from Log::Dispatchouli. You can read its documentation to understand them better.
has_log_file
Determines if log_file was specified.
has_log_path
Determines if log_path was specified.
log
Log a message.
log_debug
Log a message only if in debug mode.
log_fatal
Log a message and die.
set_debug
Set the debug flag.
clear_debug
Clear the debug flag.
set_prefix
Set a prefix for all next messages.
clear_prefix
Clears the prefix for all next messages.
set_muted
Sets the mute property, which makes only fatal messages logged.
clear_muted
Clears the mute property.
BUILDARGS
You shouldn't care about this. It takes care of propagating attributes from a given logger (if you provided one) to the attributes this role provides.
log_fields
DEPRECATED.
Please pass the logger attribute instead:
SomeObject->new( logger => $parent->logger );DEBUGGING
Occassionally you might encounter the following error:
no ident specified when using Log::Dispatchouli at Loggable.pm line 117.The problem does not stem from MooseX::Role::Loggable, but from a builder calling a logging method before the logger is built. Since Moo and Moose do not assure order of building attributes, some attributes might not yet exist by the time you need them.
This specific error happens when the ident attribute isn't built by the time a builder runs. In order to avoid it, the attribute which uses the builder should be made lazy, and then called in the BUILD method. Here is an example:
package Stuff;
use Moose;
with 'MooseX::Role::Logger';
has db => (
is => 'ro',
lazy => 1,
builder => '_build_db',
}
sub _build_db {
my $self = shift;
$self->log_debug('Building DB');
...
}
sub BUILD {
my $self = shift;
$self->db;
}This makes the db attribute non-lazy, but during run-time. This will assure that all the logging attributes are created before you build the db attribute and call log_debug.
AUTHOR
Sawyer X <xsawyerx@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2017 by Sawyer X.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.