Ehh

Ehh is an experimental web microframework.

Usage

examples/pastebin.ru

require "ehh"
require "securerandom"
require "sqlite3"

module MyApp
  class Repo
    def initialize
      @db = SQLite3::Database.new("db.sqlite3")
    end

    def setup
      @db.execute("CREATE TABLE IF NOT EXISTS posts (id TEXT, body BLOB)")
      @db.execute("CREATE UNIQUE INDEX IF NOT EXISTS posts_id ON posts (id)")
    end

    def insert_post(id:, body:)
      @db.execute("INSERT INTO posts (id, body) VALUES (?, ?)", [id, body])
    end

    def fetch_post_body(id:)
      @db.get_first_value("SELECT body FROM posts WHERE id = ?", [id])
    end
  end

  class Root
    def call(context, request, response)
      response.status = 200
      response.set_header "Content-Type", "text/plain; charset=utf-8"
      response.write "curl #{request.base_url} -X POST -H 'Content-Type: text/plain' -d 'Hello, world!'\n"
    end
  end

  module Posts
    class Create
      def call(context, request, response)
        post_id = SecureRandom.uuid

        context.repo.insert_post(id: post_id, body: request.body.read)

        response.status = 201
        response.set_header "Content-Type", "text/plain; charset=utf-8"
        response.write "#{request.base_url}/#{post_id}"
      end
    end

    class Show
      def call(context, request, response)
        post_id = request.params.fetch("post_id")

        post_body = context.repo.fetch_post_body(id: post_id)

        if post_body
          response.status = 200
          response.set_header "Content-Type", "text/plain; charset=utf-8"
          response.write post_body
        else
          response.status = 404
          response.set_header "Content-Type", "text/plain; charset=utf-8"
          response.write "Post not found\n"
        end
      end
    end
  end
end

repo = MyApp::Repo.new
repo.setup

router = Ehh::Router.new(context: { repo: repo })
router.register("GET", %r(^/$), MyApp::Root.new)
router.register("POST", %r(^/$), MyApp::Posts::Create.new)
router.register("GET", %r(^/(?<post_id>[0-9a-f\-]+$)), MyApp::Posts::Show.new)

app = Ehh::Application.build(router: router)

run app

Components

Ehh is made up of a few bits:

• Ehh::Router: a very basic router

That's it! (for now...)

Design principles

• Prioritize ease of reading/understanding over ease of writing: no DSLs
• Leave no trace: no monkey-patching
• Composition over inheritance: no subclassing for code reuse

Installation

Add this line to your application's Gemfile:

gem 'ehh'

And then execute:

$ bundle

Or install it yourself as:

$ gem install ehh

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/ehh. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.