Class: ActiveSupport::BroadcastLogger

Inherits:
Object
  • Object
show all
Includes:
LoggerSilence
Defined in:
lib/active_support/broadcast_logger.rb

Overview

Active Support Broadcast Logger

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]

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from LoggerSilence

#silence

Methods included from Concern

#append_features, #class_methods, extended, #included, #prepend_features, #prepended

Constructor Details

#initialize(*loggers) ⇒ BroadcastLogger

Returns a new instance of BroadcastLogger.



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# File '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) ⇒ Object (private) 



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

def method_missing(name, ...)
  loggers = @broadcasts.select { |logger| logger.respond_to?(name) }

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

Instance Attribute Details

#broadcasts ⇒ Object (readonly)

Returns all the logger that are part of this broadcast.



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

def broadcasts
  @broadcasts
end

#formatter ⇒ Object

Returns the value of attribute formatter.



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

def formatter
  @formatter
end

#progname ⇒ Object

Returns the value of attribute progname.



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

def progname
  @progname
end

Instance Method Details

#<<(message) ⇒ Object 



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

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

#add ⇒ Object Also known as: log 



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

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

#broadcast_to(*loggers) ⇒ Object

Add logger(s) to the broadcast.

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



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

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

#close ⇒ Object 



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

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

#debug ⇒ Object 



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

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

#debug! ⇒ Object

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



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

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

#debug? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

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

#error ⇒ Object 



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

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

#error! ⇒ Object

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



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

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

#error? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

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

#fatal ⇒ Object 



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

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

#fatal! ⇒ Object

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



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

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

#fatal? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

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

#info ⇒ Object 



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

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

#info! ⇒ Object

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



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

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

#info? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

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

#initialize_copy(other) ⇒ Object 



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# File '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

#level ⇒ Object 



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

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

#level=(level) ⇒ Object Also known as: sev_threshold= 



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

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

#local_level=(level) ⇒ Object 



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# File '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

#stop_broadcasting_to(logger) ⇒ Object

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)



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

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

#unknown ⇒ Object 



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

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

#warn ⇒ Object 



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

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

#warn! ⇒ Object

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



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

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

#warn? ⇒ Boolean

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

Returns:

  • (Boolean) 


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

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