How to log something in Rails in an independent lo

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

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 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

You can create a Logger object yourself from inside any model. Just pass the file name to the constructor and use the object like the usual Rails logger:

class User < ActiveRecord::Base
  def my_logger
    @@my_logger ||= Logger.new("#{Rails.root}/log/my.log")
  end

  def before_save
    my_logger.info("Creating user with name #{self.name}")
  end
end

Here I used a class attribute to memoize the logger. This way it won't be created for every single User object that gets created, but you aren't required to do that. Remember also that you can inject the my_logger method directly into the ActiveRecord::Base class (or into some superclass of your own if you don't like to monkey patch too much) to share the code between your app's models.

Answer 5

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 6

I would suggest using Log4r gem for custom logging. Quoting description from its page:

Log4r is a comprehensive and flexible logging library written in Ruby for use in Ruby programs. It features a hierarchical logging system of any number of levels, custom level names, logger inheritance, multiple output destinations per log event, execution tracing, custom formatting, thread safteyness, XML and YAML configuration, and more.