mitchellh/middleware

Generalized middleware implementation for Ruby.

Middleware

This is a generalized library for using middleware patterns within your Ruby projects.

To get started, the best place to look is the user guide.

Installation

This project is distributed as a RubyGem:

$ gem install middleware

Usage

Once you create a basic middleware, you can use the builder to have a nice DSL to build middleware stacks. Calling the middleware is simple, as well.

# Basic middleware that just prints the inbound and
# outbound steps.
class Trace
  def initialize(app, value)
    @app   = app
    @value = value
  end

  def call(env)
    puts "--> #{@value}"
    @app.call(env)
    puts "<-- #{@value}"
  end
end

# Build the actual middleware stack which runs a sequence
# of slightly different versions of our middleware.
stack = Middleware::Builder.new do
  use Trace, "A"
  use Trace, "B"
  use Trace, "C"
end

# Run it!
stack.call(nil)

And the output:

--> A
--> B
--> C
<-- C
<-- B
<-- A

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Added some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request