NAME¶
Poet::Log -- Poet logging
SYNOPSIS¶
# In a conf file...
log:
defaults:
level: info
output: poet.log
layout: "%d{dd/MMM/yyyy:HH:mm:ss.SS} [%p] %c - %m - %F:%L - %P%n"
class:
CHI:
level: debug
output: chi.log
layout: "%d{dd/MMM/yyyy:HH:mm:ss.SS} %m - %P%n"
MyApp::Foo:
output: stdout
# In a script...
use Poet::Script qw($log);
# In a module...
use Poet qw($log);
# In a component...
my $log = $m->log;
# For an arbitrary category...
my $log = Poet::Log->get_logger(category => 'MyApp::Bar');
# then...
$log->error("an error occurred");
$log->debugf("arguments are: %s", \@_)
if $log->is_debug();
DESCRIPTION¶
Poet uses Log::Any and Log::Log4perl for logging, with simplified configuration
for the common case.
Log::Any is a logging abstraction that allows CPAN modules to log without
knowing about which logging framework is in use. It supports standard logging
methods ("$log->debug", "$log->is_debug") along with
sprintf variants ("$log->debugf").
Log4perl is a powerful logging package that provides just about any
logging-related feature you'd want. One of its only drawbacks is its somewhat
cumbersome configuration. So, we provide a way to configure Log4perl simply
through Poet configuration if you just want common features.
Note: Log4perl is not a strict dependency for Poet. Log messages will simply not
get logged until you install it or until you modify logging for your app.
CONFIGURATION¶
The configurations below can go in any Poet conf file, e.g.
"local.cfg" or "global/log.cfg".
Here's a simple configuration that caches everything to
"logs/poet.log" at "info" level. This is also the default
if no configuration is present.
log:
defaults:
level: info
output: poet.log
layout: %d{dd/MMM/yyyy:HH:mm:ss.SS} [%p] %c - %m - %F:%L - %P%n
Here's a more involved configuration that maintains the same default, but adds
several
categories that are logged differently:
log:
defaults:
level: info
output: poet.log
layout: "%d{dd/MMM/yyyy:HH:mm:ss.SS} [%p] %c - %m - %F:%L - %P%n"
category:
CHI:
level: debug
output: chi.log
layout: "%d{dd/MMM/yyyy:HH:mm:ss.SS} %m - %P%n"
MyApp::Foo:
output: stdout
For the default and for each category, you can specify three different settings:
- •
- level - one of the valid log4perl levels (fatal, error, warn, info, debug,
trace)
- •
- output - can be a relative filename (which will be placed in the Poet log
directory), an absolute filename, or the special names "stdout"
or "stderr"
- •
- layout - a valid log4perl PatternLayout string.
If a setting isn't defined for a specific category then it falls back to the
default. In this example, "MyApp::Foo" will inherit the default
level and layout.
Notice that we use '::' instead of '.' to specify hierarchical category names,
because '.' would interfere with Poet::Conf dot notation.
Finally, if you must use a full Log4perl configuration file, you can specify it
this way:
log:
log4perl_conf: /path/to/log4perl.conf
USAGE¶
Obtaining log handle¶
- •
- In a script (log category will be 'main'):
use Poet::Script qw($log);
- •
- In a module "MyApp::Foo" (log category will be 'MyApp::Foo'):
use Poet qw($log);
- •
- In a component "/foo/bar" (log category will be
'Mason::Component::foo::bar'):
my $log = $m->log;
- •
- Manually for an arbitrary log category:
my $log = Poet::Log->get_logger(category => 'Some::Category');
# or
my $log = MyApp::Log->get_logger(category => 'Some::Category');
Using log handle¶
$log->error("an error occurred");
$log->debugf("arguments are: %s", \@_)
if $log->is_debug();
See "Log::Any|Log::Any" for more details.
MODIFIABLE METHODS¶
These methods are not intended to be called externally, but may be useful to
override or modify with method modifiers in subclasses. Their APIs will be
kept as stable as possible.
- initialize_logging
- Called once when the Poet environment is initialized. By default,
initializes log4perl with the results of
"generate_log4perl_config" and then calls
"Log::Any::Adapter->set('Log4perl')". You can modify this to
initialize log4perl in your own way, or use a different Log::Any adapter,
or use a completely different logging system.
- generate_log4perl_config
- Returns a log4perl config string based on Poet configuration. You can
modify this to construct and return your own config.
SEE ALSO¶
Poet
AUTHOR¶
Jonathan Swartz <swartz@pobox.com>
COPYRIGHT AND LICENSE¶
This software is copyright (c) 2012 by Jonathan Swartz.
This is free software; you can redistribute it and/or modify it under the same
terms as the Perl 5 programming language system itself.