Logging
by Tim Pease
== DESCRIPTION
Logging is a flexible logging library for use in Ruby programs based on the
design of Java's log4j library. It features a hierarchical logging system,
custom level names, multiple output destinations per log event, custom
formatting, and more.
== INSTALL
sudo gem install logging
== EXAMPLE
This example configures a logger to output messages in a format similar to the
core ruby Logger class. Only log messages that are warnings or higher will be
logged.
require 'logging'
logger = Logging.logger(STDOUT)
logger.level = :warn
logger.debug "this debug message will not be output by the logger"
logger.warn "this is your last warning"
In this example, a single logger is crated that will append to STDOUT and to a
file. Only log messages that are informational or higher will be logged.
require 'logging'
logger = Logging::Logger['example_logger']
logger.add_appenders(
Logging::Appender.stdout,
Logging::Appenders::File.new('example.log')
)
logger.level = :info
logger.debug "this debug message will not be output by the logger"
logger.info "just some friendly advice"
The Logging library was created to allow each class in a program to have its
own configurable logger. The logging level for a particular class can be
changed independently of all other loggers in the system. This example shows
the recommended way of accomplishing this.
require 'logging'
Logging::Logger['FirstClass'].level = :warn
Logging::Logger['SecondClass'].level = :debug
class FirstClass
def initialize
@log = Logging::Logger[self]
end
def some_method
@log.debug "some method was called on #{self.inspect}"
end
end
class SecondClass
def initialize
@log = Logging::Logger[self]
end
def another_method
@log.debug "another method was called on #{self.inspect}"
end
end
== NOTES
Although Logging is intended to supersede Log4r, it is not a one-to-one
replacement for the Log4r library. Most notably is the difference in namespaces
-- Logging vs. Log4r. Other differences include renaming Log4r::Outputter to
Logging::Appender and renaming Log4r::Formatter to Logging::Layout. These
changes were meant to bring the Logging class names more in line with the Log4j
class names.
== REQUIREMENTS
Logging requires the "lockfile" gem to run and the "flexmock" gem to run the
tests"
== DEVELOPMENT REQUIREMENTS
The Logging source code relies on the Mr Bones project for default rake tasks.
You will need to install the Mr Bones gem if you want to build or test the
logging gem.
gem install bones
== LICENSE
Ruby