Module: ActiveSupport::TaggedLogging

Defined in:
lib/active_support/tagged_logging.rb

Overview

Active Support Tagged Logging

Wraps any standard Logger object to provide tagging capabilities.

May be called with a block:

logger = ActiveSupport::TaggedLogging.new(Logger.new(STDOUT))
logger.tagged('BCX') { logger.info 'Stuff' }                                  # Logs "[BCX] Stuff"
logger.tagged('BCX', "Jason") { |tagged_logger| tagged_logger.info 'Stuff' }  # Logs "[BCX] [Jason] Stuff"
logger.tagged('BCX') { logger.tagged('Jason') { logger.info 'Stuff' } }       # Logs "[BCX] [Jason] Stuff"

If called without a block, a new logger will be returned with applied tags:

logger = ActiveSupport::TaggedLogging.new(Logger.new(STDOUT))
logger.tagged("BCX").info "Stuff"                 # Logs "[BCX] Stuff"
logger.tagged("BCX", "Jason").info "Stuff"        # Logs "[BCX] [Jason] Stuff"
logger.tagged("BCX").tagged("Jason").info "Stuff" # Logs "[BCX] [Jason] Stuff"

This is used by the default Rails.logger as configured by Railties to make it easy to stamp log lines with subdomains, request ids, and anything else to aid debugging of multi-user production applications.

Defined Under Namespace

Modules: Formatter, LocalTagStorage Classes: TagStack

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.logger(*args, **kwargs) ⇒ Object

Returns an ‘ActiveSupport::Logger` that has already been wrapped with tagged logging concern.



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# File 'lib/active_support/tagged_logging.rb', line 117

def self.logger(*args, **kwargs)
  new ActiveSupport::Logger.new(*args, **kwargs)
end

.new(logger) ⇒ Object 



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

def self.new(logger)
  logger = logger.clone

  if logger.formatter
    logger.formatter = logger.formatter.clone

    # Workaround for https://bugs.ruby-lang.org/issues/20250
    # Can be removed when Ruby 3.4 is the least supported version.
    logger.formatter.object_id if logger.formatter.is_a?(Proc)
  else
    # Ensure we set a default formatter so we aren't extending nil!
    logger.formatter = ActiveSupport::Logger::SimpleFormatter.new
  end

  logger.formatter.extend Formatter
  logger.extend(self)
end

Instance Method Details

#flush ⇒ Object 



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# File 'lib/active_support/tagged_logging.rb', line 152

def flush
  clear_tags!
  super if defined?(super)
end

#tagged(*tags) ⇒ Object 



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

def tagged(*tags)
  if block_given?
    formatter.tagged(*tags) { yield self }
  else
    logger = ActiveSupport::TaggedLogging.new(self)
    logger.formatter.extend LocalTagStorage
    logger.push_tags(*formatter.current_tags, *tags)
    logger
  end
end