Cross-Origin Resource Sharing in Ruby on Rails Application

While working in Ruby on Rails application I faced a problem with Cross-Origin Resource Sharing. Here is the configuration below how to sort out this problem:

Rack::Cors provides support for Cross-Origin Resource Sharing

Steps to enable rackcors :

1.add gem to your Gemfile:

gem 'rack-cors'

2.Add below code to config/application.rb

# if you are using Rails 3/4

config.middleware.insert_before 0, "Rack::Cors" do

  allow do

    origins '*'

    resource '*', :headers => :any, :methods => :any

  end

end

# if you are using Rails 5

config.middleware.insert_before 0, Rack::Cors do

  allow do

    origins '*'

    resource '*', headers: :any, methods: :any

  end

end

Ruby on Rails Basic Commands

To create app:

rails new your_app

To start server:

rails s or rails server

To remove model:

bundle exec rake db:rollback 

rails destroy model <model_name>

To clear db:

rails db:purge
rails db:migrate

rails db:seed

Or all together.

rails db:purge db:migrate db:seed

ReactJs Component Life Cycle - Creation/Update

Creation:

constructor() // Call super(props), Do: Set up State, Don't: Cause Side-Effects

getDerivedStateFromProps() // Do: Sync state, Don't: Cause Side-Effects

render() // Prepare & Structure JSX Code

Render Child Components //

componentDidMount() // Do: Cause Side-Effects, Don't: Update State (triggers re-render)

Update:

getDerivedStateFromProps(props, state) // Do: Sync state to props, Don't: Cause Side-Effects

shouldComponentUpdate(nextProps, nextState) // Do: Decide whether to continue or not, Don't: Cause side-effects

render() // Prepare & Structure JSX Code

Render Child Components //

getSnapshotBeforeUpdate(prevProps, prevState) // Do: Last minute DOM ops, Dont: Cause side-effects

componentDidUpdate() // Do: Cause Side-Effects, Don't: Update State (triggers re-render)