Sharing the Code

Programming stuff that might be useful to others

Ember CLI and Rails Development Setup

Ember CLI allows you to separate the client-side code from the server-side. During development your Ember app can run on one server by typing:

ember server

And your Rails API can run on another:

rails server

But the browser doesn’t allow you to make AJAX requests to a different server, you will get the following error:

No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:4200' is therefore not allowed access. The response had HTTP status code 404.

But there is a thing called Cross Origin Resource Sharing or CORS which allows you to do it in modern browsers as longs as the server is setup correctly. So below I’ve set it up for Rails in development mode only:

[sourcecode language=”ruby”]
group :development do
gem ‘rack-cors’, require: ‘rack/cors’

Then type the following in your Rails project:

bundle install

And then add the following to config/environments/development.rb and restart the Rails server.

[sourcecode language=”ruby”]
Webapp::Application.configure do

config.middleware.use Rack::Cors do
allow do
origins ‘*’
resource ‘*’, headers: :any, methods: [:get, :post, :put, :delete, : options]

So for each request the browser sends an OPTIONS request first and the server returns a response with some extra headers. The browser is then able to make the original request.

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