Programming in Ruby On Rails

Neo4j is a graph database, using neo4j gem( https://github.com/neo4jrb/neo4 j) we can easily use neo4j database in our ruby on rails application ( http://programminginrubyonrails.blogspot.in/2014/12/neo-4j-with-rails.html ). Till now neo4j gem does not support rake db tasks. You can check all the supported task by typing rake -T in your console. Now we can create our own custom rake task to seed some  data in neo4j . Step 1: Create a file under lib/tasks name it seed.rake Step 2: Put the below code in seed.rake. namespace :db do   desc 'Load the seed data from db/seeds.rb'   task :seed => :environment do     seed_file = File.join(Rails.root, 'db', 'seeds.rb')     load(seed_file) if File.exist?(seed_file)   end end That's it. now you can run rake db:seed from your terminal.. Simple :) 

How to setup new 4j database with Rails 4. Step 1: Install Neo4j Database in ubuntu.   login as Admin  sudo -i  wget -O - http://debian.neo4j.org/neotechnology.gpg.key | apt-key add -  Add Neo4J to the Apt sources list:   echo 'deb http://debian.neo4j.org/repo stable/' > /etc/apt/sources.list.d/neo4j.list  Update the package manager:  exit as admin  apt-get update  Install Neo4J:  apt-get install neo4j  sudo /etc/init.d/neo4j-service restart Step 2: Create a new rails project.  Rails new neo4j Step 3:  Add neo4j Gem in your gem file   gem 'neo4j', github: 'andreasronge/neo4j' Step 4: Go to application.rb require File.expand_path('../boot', __FILE__) require "rails" %w(   neo4j   action_controller   action_mailer   sprockets ).each do |framework|   begin     require "#{framework}/railtie"   rescue LoadError   end end # Require the gems listed in Gemfile, including any gems # you've

We can create a RESTful API using Grape and RABL in Rails4. Step 1: Add this GEMS in your Gem file, And do Bundle install.  gem 'grape'  gem 'rabl-rails'  gem 'grape-rabl'  gem 'rack-cors', :require => 'rack/cors' Step 2: Create a file under lib directory called api.rb, and create a folder inside the view named as api. # lib/api/v1/root.rb class API < Grape::API end Step 3: Add this line to your application.rb file    config.paths.add "app/api", glob: "**/*.rb"     config.autoload_paths += %W(#{config.root}/lib #{config.root}/app/api/*)     config.middleware.use Rack::Cors do       allow do         origins '*'         # location of your API         resource '/*', :headers => :any, :methods => [:get, :post, :options, :put, :delete]       end     end     config.middleware.use(Rack::Config) do |env|       env['api.tilt.root'] = Rails.root.join "app", "

How to set up jruby with apache and passenger in amazone ec2. Step 1: First install jruby using please check the current version in the   link . And make sure you are installing the bin version of it wget 'http://jruby.org.s3.amazonaws.com/downloads/1.7.4/jruby-bin-1.7.4.tar.gz' Step 2: extract the tar file using tar zxvf jruby-bin-1.7.4.tar.gz Step 3: We need to set come environment variable so that it will be accessible from every other place. export JRUBY_HOME=/home/home_directory_name/jruby-1.7.4 export PATH=$JRUBY_HOME/bin:$PATH And Open the .bashrc file and put the path in their sudo nano ~/.bashrc PATH=$PATH:/home/ubuntu/jruby-1.7.4/bin Step 4: Now to check if jruby is properly installed or not put jruby-v If your system does not have java installed then it will show an error like /home/ubuntu/jruby-1.7.4/bin/jruby: line 395: exec: java: not found Don't worry we will install java to fix this. sudo apt-get install openjdk-7-jdk apt-cache

First we need to install ruby Step 1)Install Ruby apt-get -y update apt-get -y install build-essential zlib1g-dev libssl-dev libreadline6-dev libyaml-dev cd /tmp wget http://cache.ruby-lang.org/pub/ruby/2.0/ruby-2.0.0-p247.tar.gz tar -xvzf ruby-2.0.0-p247.tar.gz cd ruby-2.0.0-p247/ ./configure --prefix=/usr/local make make install Step 2) Install Rails gem install rails 4.0.1 Step 3) Install passenger gem install passenger Step 4) Install Apache2 apt-get install apache2 Step 5) Install Mysql sudo apt-get install mysql-server mysql-client That's it we are done with the setup.

This is a powerful feature of rails to communicate between two models in two different application running in two different server. ActiveResource:Base is the main class for mapping RESTful resources as models in a Rails application. Active Resource objects represent your RESTful resources as manipulatable Ruby objects. To map resources to Ruby objects, Active Resource  only needs a class name that corresponds to the resource name (e.g., the class User maps to the resources Products, very similarly to Active Record) and a site value, which holds the URI of the resources. class User < ActiveResource::Base   self.site = "http://api.products.com:3000/" end In order to access products.com controller you need to send the json response like i am going to call the index action so we need to write :- def index @products = Product.all respond_to do |format| format.json { render :json => @products} end end Now the User class is mapped to RESTful resources located

Sending emails in a rails application is very easy and quite handy using action mailer. First we will go through the basic setup of action mailer then we will go in details how it works. Step 1   We can setup a mailer class using rails generator   rails generate mailer UserMailer Step 2   Then we can create any instance method inside it.     def welcome_email(user)       @user = user       @url  = 'http://example.com/login'       mail(to: @user.email, subject: 'Welcome')     end Step 3   We can call this method form model or controller or any kind of callbacks using    Like     UserMailer.welcome_email(@user).deliver Step 4   You can set up a view template for the welcome_email in side the views/mailer directory   Like   welcome_email.html.erb   and you can specify the layout format here and can also access the instance variables defined in the       welcome_email(user) method Step 5   Additionally we can set up the smtp configuration inside