What is custom Rails middleware and how do I create one?

What is custom Rails middleware and how do I create one?

Custom Rails middleware is a way to add functionality to your Rails application by processing requests and responses. You can create one by defining a class with a call method.

Can you give me an example of a simple middleware?

Sure! Here's a simple example that logs request details:

class LoggerMiddleware
  def initialize(app)
    @app = app
  end

  def call(env)
    puts "Request: \\#{env['REQUEST_METHOD']} \\#{env['PATH_INFO']}"
    @app.call(env)
  end
end

How do I add this middleware to my Rails app?

You can add it in your config/application.rb file like this:

config.middleware.use LoggerMiddleware

What are some common use cases for middleware?

Common use cases include logging, authentication, and modifying request/response headers.