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 


82
83
84
85
86
87
88
89
90
91
92
93
94
 
# File 'activesupport/lib/active_support/tagged_logging.rb', line 82

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

  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

#broadcast_to(other_logger) ⇒ Object

:nodoc:


98
99
100
101
102
103
104
105
106
107
108
109
110
 
# File 'activesupport/lib/active_support/tagged_logging.rb', line 98

def broadcast_to(other_logger) # :nodoc:
  define_singleton_method(:formatter=) do |formatter|
    other_logger.formatter ||= formatter

    other_logger.formatter.singleton_class.redefine_method(:current_tags) do
      formatter.current_tags
    end

    super(formatter)
  end

  self.formatter = self.formatter.clone
end

#flush ⇒ Object 


123
124
125
126
 
# File 'activesupport/lib/active_support/tagged_logging.rb', line 123

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

#tagged(*tags) ⇒ Object 


112
113
114
115
116
117
118
119
120
121
 
# File 'activesupport/lib/active_support/tagged_logging.rb', line 112

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