How to log something in Rails in an independent log file?

Question

In rails I want to log some information in a different log file and not the standard development.log or production.log. I want to do this logging from a model class.

Answer 1

Here is my custom logger:

class DebugLog
  def self.debug(message=nil)
    return unless Rails.env.development? and message.present?
    @logger ||= Logger.new(File.join(Rails.root, 'log', 'debug.log'))
    @logger.debug(message) 
  end
end

Answer 2

class Article < ActiveRecord::Base  

      LOGFILE = File.join(RAILS_ROOT, '/log/', "article_#{RAILS_ENV}.log")  

      def validate  
        log "was validated!"  
      end   

      def log(*args)  
       args.size == 1 ? (message = args; severity = :info) : (severity, message = args)  
       Article.logger severity, "Article##{self.id}: #{message}"  
     end  

     def self.logger(severity = nil, message = nil)  
       @article_logger ||= Article.open_log  
       if !severity.nil? && !message.nil? && @article_logger.respond_to?(severity)  
         @article_logger.send severity, "[#{Time.now.to_s(:db)}] [#{severity.to_s.capitalize}] #{message}\n"  
       end  
       message or @article_logger  
     end  

     def self.open_log  
       ActiveSupport::BufferedLogger.new(LOGFILE)  
     end  

   end  

Answer 3

The Logging framework, with its deceptively simple name, has the sophistication you crave!

Follow the very short instructions of logging-rails to get started filtering out noise, getting alerts, and choosing output in a fine-grained and high-level way.

Pat yourself on the back when you are done. Log-rolling, daily. Worth it for that alone.

Answer 4

class Post < ActiveRecord::Base
    def initialize(attributes)
        super(attributes)
        @logger = Logger.new("#{Rails.root}/log/post.log")
    end

    def logger
        @logger
    end

    def some_method
        logger.info('Test 1')
    end
end

ps = Post.new
ps.some_method
ps.logger.info('Test 2')
Post.new.logger.info('Test 3')

Answer 5

A decent option that works for me is to just add a fairly plain class to your app/models folder such as app/models/my_log.rb

class MyLog
  def self.debug(message=nil)
    @my_log ||= Logger.new("#{Rails.root}/log/my.log")
    @my_log.debug(message) unless message.nil?
  end
end

then in your controller, or really almost anywhere that you could reference a model's class from within your rails app, i.e. anywhere you could do Post.create(:title => "Hello world", :contents => "Lorum ipsum"); or something similar you can log to your custom file like this

MyLog.debug "Hello world"

Answer 6

Define a logger class in (say) app/models/special_log.rb:

class SpecialLog
  LogFile = Rails.root.join('log', 'special.log')
  class << self
    cattr_accessor :logger
    delegate :debug, :info, :warn, :error, :fatal, :to => :logger
  end
end

initialize the logger in (say) config/initializers/special_log.rb:

SpecialLog.logger = Logger.new(SpecialLog::LogFile)
SpecialLog.logger.level = 'debug' # could be debug, info, warn, error or fatal

Anywhere in your app, you can log with:

SpecialLog.debug("something went wrong")
# or
SpecialLog.info("life is good")