Ruby » Ruby master

#

# == Description

#

# Logger::Application --- Add logging support to your application.

#

# == Usage

#

# 1. Define your application class as a sub-class of this class.

# 2. Override the +run+ method in your class to do many things.

# 3. Instantiate it and invoke #start.

#

# == Example

#

# class FooApp < Logger::Application

# def initialize(foo_app, application_specific, arguments)

# super('FooApp') # Name of the application.

# end

#

# def run

# ...

# log(WARN, 'warning', 'my_method1')

# ...

# @log.error('my_method2') { 'Error!' }

# ...

# end

# end

#

# status = FooApp.new(....).start

#

class Application

include Logger::Severity

# Name of the application given at initialize.

attr_reader :appname

#

# :call-seq:

# Logger::Application.new(appname = '')

#

# == Args

#

# +appname+:: Name of the application.

#

# == Description

#

# Create an instance. Log device is +STDERR+ by default. This can be

# changed with #set_log.

#

def initialize(appname = nil)

@appname = appname

@log = Logger.new(STDERR)

@log.progname = @appname

@level = @log.level

end

#

# Start the application. Return the status code.

#

def start

status = -1

begin

log(INFO, "Start of #{ @appname }.")

status = run

rescue

log(FATAL, "Detected an exception. Stopping ... #{$!} (#{$!.class})\n" << $@.join("\n"))

ensure

log(INFO, "End of #{ @appname }. (status: #{ status.to_s })")

end

status

end

# Logger for this application. See the class Logger for an explanation.

def logger

@log

end

#

# Sets the logger for this application. See the class Logger for an

# explanation.

#

def logger=(logger)

@log = logger

@log.progname = @appname

@log.level = @level

end

#

# Sets the log device for this application. See <tt>Logger.new</tt> for

# an explanation of the arguments.

#

def set_log(logdev, shift_age = 0, shift_size = 1024000)

@log = Logger.new(logdev, shift_age, shift_size)

@log.progname = @appname

@log.level = @level

end

def log=(logdev)

set_log(logdev)

end

#

# Set the logging threshold, just like <tt>Logger#level=</tt>.

#

def level=(level)

@level = level

@log.level = @level

end

#

# See Logger#add. This application's +appname+ is used.

#

def log(severity, message = nil, &block)

@log.add(severity, message, @appname, &block) if @log

end

private

def run

# TODO: should be an NotImplementedError

raise RuntimeError.new('Method run must be defined in the derived class.')

end

end

require 'logger'