DZone Snippets: Mickael's Code Snippets

Add rails log to console

Mickael (Mickael) — Tue, 31 Jul 2007 11:16:56 GMT

In order to show rails log in console, add theses lines to your .irbrc



if ENV.include?('RAILS_ENV')&& !Object.const_defined?('RAILS_DEFAULT_LOGGER')

  Object.const_set('RAILS_DEFAULT_LOGGER', Logger.new(SDTOUT))

end

Converting Mysql Tables in InnoDB

Mickael (Mickael) — Thu, 19 Jul 2007 12:43:43 GMT

// description of your code here



class ConvertMysqlToInnodb < ActiveRecord::Migration

 def self.up

   config = ActiveRecord::Base.configurations

   begin

     STDERR.puts "Migrating all existing tables to InnoDB"

     schema = []

     select_all('SHOW TABLES').inject([]) do |schema, table|

       schema << "ALTER TABLE #{table.to_a.first.last} ENGINE=InnoDB"

     end

     schema.each { |line| execute line }

   end if config[RAILS_ENV]['adapter'] == 'mysql' unless $schema_generator

 end

source http://trac.typosphere.org/browser/trunk/db/migrate/015_convert_mysql_to_innodb.rb



 def self.down

   # don't do anything

   # this is a one-way migration, but it's not "irreversable"

   # because it doesn't change any code logic

 end

end

Daemonize a Ruby process

Mickael (Mickael) — Thu, 08 Mar 2007 09:42:01 GMT

// description of your code here
from : http://scie.nti.st/2006/12/15/daemonize-a-ruby-process
Here's a neat thing I found. I needed a small bit of Ruby code to run continuously in the background, but because of how Capistrano can't seem to work well with "nohup" and "&" (background job), my ruby script itself needed to be able to fork and detach from the terminal. Here's how you do it:



#!/usr/bin/ruby



pid = fork do

  Signal.trap('HUP', 'IGNORE') # Don't die upon logout



  loop do



    // Some code



    sleep 60

  end

end



Process.detach(pid)

Generate random password in ruby

Mickael (Mickael) — Tue, 06 Mar 2007 08:51:55 GMT

Aaron Blohowiak suggests adding this as a public method in user.rb:



def new_random_password

  self.password= Digest::SHA1.hexdigest("--#{Time.now.to_s}--#{login}--")[0,6]

  self.password_confirmation = self.password

end

Init rails project script

Mickael (Mickael) — Fri, 09 Feb 2007 12:52:42 GMT

From http://vinsol.com/2007/02/08/ruby-script-for-creating-new-rails-project-and-initial-svn-import-with-ignoringremoving-logother-files



require 'fileutils'



puts  "########################################"

puts  "This script creates a new rails project and do the initial svn import with ignoring/deleting files from subversion"

puts  "Please send your feedback to Akhil Bansal"

puts  "I have tested this script and it works great on my system."

puts  ""

puts  ""

puts  "                    ###### ATTENTION #######"

puts  ""

puts  ""

puts  "Use this script at your own risk, if your computer explodes its not my fault :-) "

puts  "#######################################"



puts  "Enter svn username: "

username = gets.strip

puts  "Enter the svn url: "

svn_url =gets.strip



puts  "Enter Rails Application Path:(eg: /home/akhil/ror): "

app_path = gets.strip

puts  "Enter Application Name: "

app_name = gets.strip



puts  "######################################"





puts  "Please verify the following variables: "

puts  "Svn Username: #{username}"

puts  "Svn URL: #{svn_url}"

puts  "Application Path: #{app_path}"

puts  "Application name: #{app_name}"



puts  "Proceed (y/n)"

proceed = gets

proceed = proceed.strip.upcase

if proceed == 'N' 

    puts  "Terminating..."

    exit 0

elsif proceed == 'Y' 

    if system("rails -v")

      s="/"

    elsif   system("rails.cmd -v")

      s="\\"

    else

        puts "Cannot find rails. Terminating..."

        exit 0

    end    

    app_root=app_path+s+ app_name

    

    puts  "Generating rails project: (#{app_root})"

    if system("rails #{app_root}")

      s="/"

    elsif   system("rails.cmd #{app_root}")

      s="\\"

    else

        puts "Cannot create rails project. Terminating..."

        exit 0

    end    

    

    puts  "SVNinitial import: "

    system("svn import #{app_root} #{svn_url} -m \"Initial Import\" --username #{username}")

   

    FileUtils.remove_dir(app_root, true)

   

    puts  "Checking out from svn: "



    system("svn checkout #{svn_url} #{app_root}")

    FileUtils.cd(app_root, :verbose => true)

    

    puts  "Removing all log files from SVN"

    system("svn remove log"+s+"*")

    puts  "commiting..."

    system("svn commit -m \"removing all log files from subversion \" ")

    puts  "Ignoring all log files under log dir"

    system("svn propset svn:ignore \"*.log\" log"+s)

    puts  "Updating and commiting..."

    system("svn update log"+s)

    system("svn commit -m \"Ignoring all files in "+s+"log"+s+" ending in .log \" ")

    puts  "Removing tmp directory from SVN"

    system("svn remove tmp"+s)

    puts  "commiting..."

    system("svn commit -m \"removing the temp directory from subversion \" ")

    puts  "Ignoring tmp dir"

    system("svn propset svn:ignore \"*\" tmp"+s)

    puts  "Updating and commiting again...."



    system("svn update tmp"+s)

    system("svn commit -m \"Ignore the whole tmp"+s+" directory, might not work on subdirectories? \" ")

    puts  "Moving database.yml to database.example"

    system("svn move config"+s+"database.yml config"+s+"database.example")

    puts  "commiting..."

    system("svn commit -m \"Moving database.yml to database.example to provide a template for anyone who checks out the code \" ")

    puts  "Ignoring database.yml , updating and commiting..."

    system("svn propset svn:ignore 'database.yml' config"+s)

    system("svn update config"+s)

    system("svn commit -m \"Ignoring database.yml\" ")

    puts  "Finished."



else

    puts  "Unknown Input. Terminating..."

	exit 0

end

Property change listener

Mickael (Mickael) — Thu, 08 Feb 2007 16:00:35 GMT

How to implement a Property change listener on ruby class
Origin : http://rawblock.blogspot.com/2007/02/transparent-property-change-listeners.html



class ListenerSupport

 

  def self.listen_to(klass, *properties)

    setup(klass)

    properties.each do |p|

      klass.instance_eval do

        #rename original method

        alias_method "#{p}_orig=", "#{p}="

        #create proxy method in it's place that will fire

        #changes, and delegate to the original implementation

        define_method "#{p}=" do |value|

          old_value = send "#{p}"

          send "#{p}_orig=",value

          fire_property_changed p, old_value, value

        end

      end

    end

  end

 

  def self.setup(klass)

    klass.instance_eval do

     

      define_method :fire_property_changed do |prop, pre, post|

        return if pre == post

        eval %{

          @listeners[prop].each do |l|

              l.property_changed(self, prop, pre, post)

          end unless @listeners.nil?

        }

      end unless instance_methods.include? :fire_property_changed

     

      define_method :add_property_listener do |prop, listener|

        eval %{

          @listeners = {} if @listeners.nil?

          prop_listeners = @listeners.include?(prop) ? @listeners[prop] : []

          @listeners[prop] = prop_listeners

          prop_listeners << listener unless prop_listeners.include? listener

        }

      end unless instance_methods.include? :add_property_listener

     

    end

  end

 

end

The general idea is that the original class is modified so that all properties that are listened to have their accessor write methods intercepted, and any property change listeners are notified when that property changes.

Let's walk through how it works:

* A standard Ruby class with property accessors is created. e.g.

class RubyBean
attr_accessor :foo, :bar
end

* A call to ListenerSupport.listen_to is made to modify the class to allow properties to be listened to.

ListenerSupport.listen_to RubyBean, :foo, :bar

* listen_to adds methods add_property_listener and fire_property_changed to allow listeners to be added to RubyBean for specific properties.
* listen_to then aliases the original methods foo= and bar= to foo_orig= and bar_orig=. New methods for foo= and bar= are defined that delegate the work to the original method, then call fire_property_changed to notify the listeners.
* Listeners are called, and any custom action (such as GUI component binding) can be carried out.

Putting the errors in the right place

Mickael (Mickael) — Thu, 01 Feb 2007 14:06:27 GMT

The idea is to display the error near the field instead of in global area at the top of the page.
Simple… first go into your view and delete the



error_messages_for ‘object’

Then stick this in your application helper.

# application_helper.rb
def error_for(object, method = nil, options={})
if method
err = instance_variable_get("@#{object}").errors.on(method).to_sentence rescue instance_variable_get("@#{object}").errors.on(method)
else
err = @errors["#{object}"] rescue nil
end
options.merge!(:class=>’fieldWithErrors’,
:id=>"#{[object,method].compact.join(’_')}-error",
:style=>(err ? #{options[:style]}":"#{options[:style]};display: none;")
)
content_tag("p",err || "", options )
end

Then in your form view, add an ‘error_for’ call wherever you need one…



# _form.rhtml

  Name

  <%= text_field ‘code_project’, ‘name’  %>

  <%= error_for ‘code_project’, ‘name’ %>

If the model fails a validation test, then it will show the message right next to the field that caused the validation problem.
Also note that if you define an instance variable called @errors containing a hash of field_names and messages, they will also be used. This is handy for those form fields that don’t correspond to a model attribute.

Active Record log

Mickael (Mickael) — Thu, 01 Feb 2007 13:45:53 GMT

from

In config/environment.rb:



def log_to(stream)

  ActiveRecord::Base.logger = Logger.new(stream)

  ActiveRecord::Base.clear_active_connections!

end

then in the console :



>> log_to STDOUT

=> ...

>> Post.find(:first)

  Post Load (0.000138)   SELECT * FROM posts LIMIT 1

=> #

>>

The best part is, by clearing the active connections after setting the logger, you can change the logger at any time, even after you’ve made any number of find calls.

And, you can pass your own stream objects into it:



>> buffer = StringIO.new

=> ...

>> log_to buffer

=> ...

>> Post.find(:first)

=> #

>> p buffer.string

=> "  \e[4;35;1mPost Load (0.000138)\e[0m   \e[0mSELECT * FROM posts LIMIT 1\e[0m\n"

>>

Request Database Authentication

Mickael (Mickael) — Tue, 30 Jan 2007 13:52:26 GMT

Simple solution to a problem that may not affect very many folks.
If you don't like your password displayed in plain text in database.yml, this might help you.
It utilizes the Highline gem (big thanks to James Edward Gray II).



# database.yml



<%

require 'highline/import'



def request_input(msg, show_input = true)

  ask(msg) { |q| q.echo = show_input }

end

%>



#...

  username: <%= request_input 'Username: ' %>

  password: <%= request_input 'Password: ', false %>

#...

Rails mot reserve

Mickael (Mickael) — Fri, 26 Jan 2007 21:26:33 GMT

Mot réservés en rails



ruby -r config/environment -e 'print Object.constants.sort.join(", ")'