Cross-Origin Resource Sharing (CORS) is a mechanism that uses additional HTTP headers to tell browsers to give a web application running at one origin, access to selected resources from a different origin. A web application executes a cross-origin HTTP request when it requests a resource that has a different origin (domain, protocol, or port) from its own.
During the recent Rails Api Project, I met the CORS problem as below.
I found two solutions for fixing the problem.
- To get
rack-cors
working, add the gem ‘rack-cors’ to the Gemfile or uncomment the gem and runbundle install
.
2 -1. Add the following to config/application.rb
inside class Application < Rails::Application
:
2–2. Or add the following file into the ‘config/initializers’ folder or uncomment.