Mojo::Log(3)

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>.