Class: ActiveSupport::BroadcastLogger

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Instance Chain: self, `LoggerSilence`
Inherits:	Object
Defined in:	activesupport/lib/active_support/broadcast_logger.rb

Overview

The Broadcast logger is a logger used to write messages to multiple ::IO. It is commonly used in development to display messages on STDOUT and also write them to a file (development.log). With the Broadcast logger, you can broadcast your logs to a unlimited number of sinks.

The BroadcastLogger acts as a standard logger and all methods you are used to are available. However, all the methods on this logger will propagate and be delegated to the other loggers that are part of the broadcast.

Broadcasting your logs.

stdout_logger = Logger.new(STDOUT)
file_logger   = Logger.new("development.log")
broadcast = BroadcastLogger.new(stdout_logger, file_logger)

broadcast.info("Hello world!") # Writes the log to STDOUT and the development.log file.

Add a logger to the broadcast.

stdout_logger = Logger.new(STDOUT)
broadcast = BroadcastLogger.new(stdout_logger)
file_logger   = Logger.new("development.log")
broadcast.broadcast_to(file_logger)

broadcast.info("Hello world!") # Writes the log to STDOUT and the development.log file.

Modifying the log level for all broadcasted loggers.

stdout_logger = Logger.new(STDOUT)
file_logger   = Logger.new("development.log")
broadcast = BroadcastLogger.new(stdout_logger, file_logger)

broadcast.level = Logger::FATAL # Modify the log level for the whole broadcast.

Stop broadcasting log to a sink.

stdout_logger = Logger.new(STDOUT)
file_logger   = Logger.new("development.log")
broadcast = BroadcastLogger.new(stdout_logger, file_logger)
broadcast.info("Hello world!") # Writes the log to STDOUT and the development.log file.

broadcast.stop_broadcasting_to(file_logger)
broadcast.info("Hello world!") # Writes the log *only* to STDOUT.

At least one sink has to be part of the broadcast. Otherwise, your logs will not be written anywhere. For instance:

broadcast = BroadcastLogger.new
broadcast.info("Hello world") # The log message will appear nowhere.

If you are adding a custom logger with custom methods to the broadcast, the BroadcastLogger will proxy them and return the raw value, or an array of raw values, depending on how many loggers in the broadcasts responded to the method:

class MyLogger < ::Logger
  def loggable?
    true
  end
end

logger = BroadcastLogger.new
logger.loggable? # => A NoMethodError exception is raised because no loggers in the broadcasts could respond.

logger.broadcast_to(MyLogger.new(STDOUT))
logger.loggable? # => true
logger.broadcast_to(MyLogger.new(STDOUT))
puts logger.broadcasts # => [MyLogger, MyLogger]
logger.loggable? # [true, true]

`LoggerSilence` - Attributes & Methods

.silencer (also: #silencer) rw
#silencer rw

Class Method Summary

.new(*loggers) ⇒ BroadcastLogger constructor

Instance Attribute Summary

#broadcasts readonly

Returns all the logger that are part of this broadcast.
#debug? ⇒ Boolean readonly

True if the log level allows entries with severity Logger::DEBUG to be written to at least one broadcast.
#error? ⇒ Boolean readonly

True if the log level allows entries with severity Logger::ERROR to be written to at least one broadcast.
#fatal? ⇒ Boolean readonly

True if the log level allows entries with severity Logger::FATAL to be written to at least one broadcast.
#formatter rw
#formatter=(formatter) rw
#info? ⇒ Boolean readonly

True if the log level allows entries with severity Logger::INFO to be written to at least one broadcast.
#level rw
#level=(level) (also: #sev_threshold=) rw
#local_level=(level) writeonly
#progname rw
#warn? ⇒ Boolean readonly

True if the log level allows entries with severity Logger::WARN to be written to at least one broadcast.

Instance Method Summary

#<<(message)
#add (also: #log)
#broadcast_to(*loggers)

Add logger(s) to the broadcast.
#close
#debug readonly
#debug!

Sets the log level to Logger::DEBUG for the whole broadcast.
#error readonly
#error!

Sets the log level to Logger::ERROR for the whole broadcast.
#fatal readonly
#fatal!

Sets the log level to Logger::FATAL for the whole broadcast.
#info readonly
#info!

Sets the log level to Logger::INFO for the whole broadcast.
#initialize_copy(other)
#log

Alias for #add.
#stop_broadcasting_to(logger)

Remove a logger from the broadcast.
#unknown
#warn readonly
#warn!

Sets the log level to Logger::WARN for the whole broadcast.

`LoggerSilence` - Included

#silence

Silences the logger for the duration of the block.

Constructor Details

.new(*loggers) ⇒ `BroadcastLogger`

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 82


def initialize(*loggers)
  @broadcasts = []
  @progname = "Broadcast"

  broadcast_to(*loggers)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args, **kwargs, &block) (private)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 235


def method_missing(name, *args, **kwargs, &block)
  loggers = @broadcasts.select { |logger| logger.respond_to?(name) }

  if loggers.none?
    super(name, *args, **kwargs, &block)
  elsif loggers.one?
    loggers.first.send(name, *args, **kwargs, &block)
  else
    loggers.map { |logger| logger.send(name, *args, **kwargs, &block) }
  end
end

Class Attribute Details

.silencer (rw) Also known as: #silencer

[ GitHub ]

# File 'activesupport/lib/active_support/logger_silence.rb', line 12


cattr_accessor :silencer, default: true

Instance Attribute Details

#broadcasts (readonly)

Returns all the logger that are part of this broadcast.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 78


attr_reader :broadcasts

#debug? ⇒ `Boolean` (readonly)

True if the log level allows entries with severity Logger::DEBUG to be written to at least one broadcast. False otherwise.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 168


def debug?
  @broadcasts.any? { |logger| logger.debug? }
end

#error? ⇒ `Boolean` (readonly)

True if the log level allows entries with severity Logger::ERROR to be written to at least one broadcast. False otherwise.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 201


def error?
  @broadcasts.any? { |logger| logger.error? }
end

#fatal? ⇒ `Boolean` (readonly)

True if the log level allows entries with severity Logger::FATAL to be written to at least one broadcast. False otherwise.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 212


def fatal?
  @broadcasts.any? { |logger| logger.fatal? }
end

#formatter (rw)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 79


attr_reader :formatter

#formatter=(formatter) (rw)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 145


def formatter=(formatter)
  dispatch { |logger| logger.formatter = formatter }

  @formatter = formatter
end

#info? ⇒ `Boolean` (readonly)

True if the log level allows entries with severity Logger::INFO to be written to at least one broadcast. False otherwise.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 179


def info?
  @broadcasts.any? { |logger| logger.info? }
end

#level (rw)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 108


def level
  @broadcasts.map(&:level).min
end

#level=(level) (rw) Also known as: #sev_threshold=

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 151


def level=(level)
  dispatch { |logger| logger.level = level }
end

#local_level=(level) (writeonly)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 156


def local_level=(level)
  dispatch do |logger|
    logger.local_level = level if logger.respond_to?(:local_level=)
  end
end

#progname (rw)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 80


attr_accessor :progname

#silencer (rw)

[ GitHub ]

# File 'activesupport/lib/active_support/logger_silence.rb', line 12


cattr_accessor :silencer, default: true

#warn? ⇒ `Boolean` (readonly)

True if the log level allows entries with severity Logger::WARN to be written to at least one broadcast. False otherwise.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 190


def warn?
  @broadcasts.any? { |logger| logger.warn? }
end

Instance Method Details

#<<(message)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 112


def <<(message)
  dispatch { |logger| logger.<<(message) }
end

#add Also known as: #log

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 116


def add(...)
  dispatch { |logger| logger.add(...) }
end

#broadcast_to(*loggers)

Add logger(s) to the broadcast.

broadcast_logger = ActiveSupport::BroadcastLogger.new
broadcast_logger.broadcast_to(Logger.new(STDOUT), Logger.new(STDERR))

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 93


def broadcast_to(*loggers)
  @broadcasts.concat(loggers)
end

#close

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 162


def close
  dispatch { |logger| logger.close }
end

#debug (readonly)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 121


def debug(...)
  dispatch { |logger| logger.debug(...) }
end

#debug!

Sets the log level to Logger::DEBUG for the whole broadcast.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 173


def debug!
  dispatch { |logger| logger.debug! }
end

#error (readonly)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 133


def error(...)
  dispatch { |logger| logger.error(...) }
end

#error!

Sets the log level to Logger::ERROR for the whole broadcast.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 206


def error!
  dispatch { |logger| logger.error! }
end

#fatal (readonly)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 137


def fatal(...)
  dispatch { |logger| logger.fatal(...) }
end

#fatal!

Sets the log level to Logger::FATAL for the whole broadcast.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 217


def fatal!
  dispatch { |logger| logger.fatal! }
end

#info (readonly)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 125


def info(...)
  dispatch { |logger| logger.info(...) }
end

#info!

Sets the log level to Logger::INFO for the whole broadcast.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 184


def info!
  dispatch { |logger| logger.info! }
end

#initialize_copy(other)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 221


def initialize_copy(other)
  @broadcasts = []
  @progname = other.progname.dup
  @formatter = other.formatter.dup

  broadcast_to(*other.broadcasts.map(&:dup))
end

#log

Alias for #add.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 119


alias_method :log, :add

#stop_broadcasting_to(logger)

Remove a logger from the broadcast. When a logger is removed, messages sent to the broadcast will no longer be written to its sink.

sink = Logger.new(STDOUT)
broadcast_logger = ActiveSupport::BroadcastLogger.new

broadcast_logger.stop_broadcasting_to(sink)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 104


def stop_broadcasting_to(logger)
  @broadcasts.delete(logger)
end

#unknown

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 141


def unknown(...)
  dispatch { |logger| logger.unknown(...) }
end

#warn (readonly)

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 129


def warn(...)
  dispatch { |logger| logger.warn(...) }
end

#warn!

Sets the log level to Logger::WARN for the whole broadcast.

[ GitHub ]

# File 'activesupport/lib/active_support/broadcast_logger.rb', line 195


def warn!
  dispatch { |logger| logger.warn! }
end

Class: ActiveSupport::BroadcastLogger

Overview

LoggerSilence - Attributes & Methods

Class Method Summary

Instance Attribute Summary

Instance Method Summary

LoggerSilence - Included

Constructor Details

.new(*loggers) ⇒ BroadcastLogger

Dynamic Method Handling

#method_missing(name, *args, **kwargs, &block) (private)

Class Attribute Details

.silencer (rw) Also known as: #silencer

Instance Attribute Details

#broadcasts (readonly)

#debug? ⇒ Boolean (readonly)

#error? ⇒ Boolean (readonly)

#fatal? ⇒ Boolean (readonly)

#formatter (rw)

#formatter=(formatter) (rw)

#info? ⇒ Boolean (readonly)

#level (rw)

#level=(level) (rw) Also known as: #sev_threshold=

#local_level=(level) (writeonly)

#progname (rw)

#silencer (rw)

#warn? ⇒ Boolean (readonly)

Instance Method Details

#<<(message)

#add Also known as: #log

#broadcast_to(*loggers)

#close

#debug (readonly)

#debug!

#error (readonly)

#error!

#fatal (readonly)

#fatal!

#info (readonly)

#info!

#initialize_copy(other)

#log

#stop_broadcasting_to(logger)

#unknown

#warn (readonly)

#warn!

`LoggerSilence` - Attributes & Methods

`LoggerSilence` - Included

.new(*loggers) ⇒ `BroadcastLogger`

#debug? ⇒ `Boolean` (readonly)

#error? ⇒ `Boolean` (readonly)

#fatal? ⇒ `Boolean` (readonly)

#info? ⇒ `Boolean` (readonly)

#warn? ⇒ `Boolean` (readonly)