Module: ActiveSupport::TaggedLogging

Defined in:
activesupport/lib/active_support/tagged_logging.rb

Overview

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") { 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

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.new(logger) ⇒ Object 


86
87
88
89
90
91
92
93
94
95
96
97
98
 
# File 'activesupport/lib/active_support/tagged_logging.rb', line 86

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

  if logger.formatter
    logger.formatter = logger.formatter.dup
  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 


113
114
115
116
 
# File 'activesupport/lib/active_support/tagged_logging.rb', line 113

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

#tagged(*tags) ⇒ Object 


102
103
104
105
106
107
108
109
110
111
 
# File 'activesupport/lib/active_support/tagged_logging.rb', line 102

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