Module: Mojo::Log

NAME

Mojo::Log - Simple logger

SYNOPSIS

use Mojo::Log;

# Log to STDERR
my $log = Mojo::Log->new;

# Customize log file location and minimum log level
my $log = Mojo::Log->new(path => '/var/log/mojo.log', level => 'warn');

# Log messages
$log->trace('Doing stuff');
$log->debug('Not sure what is happening here');
$log->info('FYI: it happened again');
$log->warn('This might be a problem');
$log->error('Garden variety error');
$log->fatal('Boom');

DESCRIPTION

Mojo::Log is a simple logger for Mojo projects.

EVENTS

Mojo::Log inherits all events from Mojo::EventEmitter and can emit the following new ones.

message

$log->on(message => sub ($log, $level, @lines) {...});

Emitted when a new message gets logged.

$log->on(message => sub ($log, $level, @lines) { say "$level: ", @lines });

ATTRIBUTES

Mojo::Log implements the following attributes.

color

my $bool = $log->color;
$log     = $log->color($bool);

Colorize log messages with the levels warn, error and fatal using Term::ANSIColor, defaults to the value of the MOJO_LOG_COLOR environment variables. Note that this attribute is EXPERIMENTAL and might change without warning!

format

my $cb = $log->format;
$log   = $log->format(sub {...});

A callback for formatting log messages.

$log->format(sub ($time, $level, @lines) { "[2018-11-08 14:20:13.77168] [28320] [info] I ♥ Mojolicious\n" });

handle

my $handle = $log->handle;
$log       = $log->handle(IO::Handle->new);

Log filehandle used by default "message" event, defaults to opening "path" or STDERR.

history

my $history = $log->history;
$log        = $log->history([[time, 'debug', 'That went wrong']]);

The last few logged messages.

level

my $level = $log->level;
$log      = $log->level('debug');

Active log level, defaults to trace. Available log levels are trace, debug, info, warn, error and fatal, in that order.

max_history_size

my $size = $log->max_history_size;
$log     = $log->max_history_size(5);

Maximum number of logged messages to store in "history", defaults to 10.

path

my $path = $log->path
$log     = $log->path('/var/log/mojo.log');

Log file path used by "handle".

short

my $bool = $log->short;
$log     = $log->short($bool);

Generate short log messages without a timestamp but with journald log level prefix, suitable for systemd environments, defaults to the value of the MOJO_LOG_SHORT environment variables.

METHODS

Mojo::Log inherits all methods from Mojo::EventEmitter and implements the following new ones.

append

$log->append("[2018-11-08 14:20:13.77168] [28320] [info] I ♥ Mojolicious\n");

Append message to "handle".

capture

my $messages = $log->capture;
my $messages = $log->capture('debug');

Capture log messages for as long as the returned object exists, useful for testing log messages.

# Test your log messages
my $messages = $log->capture('trace');
$log->fatal('Something very bad happened');
$log->trace('Just some debug information');
like $messages, qr/Something very bad happened/, 'logs contain fatal message';
like $messages->[-1], qr/Just some debug information/, 'trace message was last';
undef $messages;

context

my $new = $log->context('[extra]', '[information]');

Construct a new child Mojo::Log object that will include context information with every log message.

# Log with context
my $log = Mojo::Log->new;
my $context = $log->context('[17a60115]');
$context->debug('This is a log message with context information');
$context->info('And another');

debug

$log = $log->debug('You screwed up, but that is ok');
$log = $log->debug('All', 'cool');
$log = $log->debug(sub {...});

Emit "message" event and log debug message.

error

$log = $log->error('You really screwed up this time');
$log = $log->error('Wow', 'seriously');
$log = $log->error(sub {...});

Emit "message" event and log error message.

fatal

$log = $log->fatal('Its over...');
$log = $log->fatal('Bye', 'bye');
$log = $log->fatal(sub {...});

Emit "message" event and log fatal message.

info

$log = $log->info('You are bad, but you prolly know already');
$log = $log->info('Ok', 'then');
$log = $log->info(sub {...});

Emit "message" event and log info message.

is_level

my $bool = $log->is_level('debug');

Check active log "level".

# True
$log->level('debug')->is_level('debug');
$log->level('debug')->is_level('info');

# False
$log->level('info')->is_level('debug');
$log->level('fatal')->is_level('warn');

new

my $log = Mojo::Log->new;
my $log = Mojo::Log->new(level => 'warn');
my $log = Mojo::Log->new({level => 'warn'});

Construct a new Mojo::Log object and subscribe to "message" event with default logger.

trace

$log = $log->trace('Whatever');
$log = $log->trace('Who', 'cares');
$log = $log->trace(sub {...});

Emit "message" event and log trace message.

warn

$log = $log->warn('Dont do that Dave...');
$log = $log->warn('No', 'really');
$log = $log->warn(sub {...});

Emit "message" event and log warn message.

SEE ALSO

Mojolicious, Mojolicious::Guides, https://mojolicious.org.