Differentiate development environment from production. You can choose themes to differentiate the page.

The running sample is available.

You can also try this gem on Heroku.

Add the rack-dev-mark gem to your Gemfile.

gem "rack-dev-mark"

And run bundle install.

require 'rack/dev-mark'
use Rack::DevMark::Middleware
run MyApp

Add the settings in config.rb.

require 'rack/dev-mark'
Rack::DevMark.env = "Your Env"
use Rack::DevMark::Middleware

In config/environments/development.rb

Rails.application.configure do
  config.rack_dev_mark.enable = true
end

Or In config/application.rb

module MyApp
  class Application < Rails::Application
    config.rack_dev_mark.enable = !Rails.env.production?
  end
end

Or Alternatively, use generator

bundle exec rails g rack:dev-mark:install

The middleware sets title and github_fork_ribbon themes as default.

Show the dev mark except env1, env2, env3.

In config/application.rb

module MyApp
  class Application < Rails::Application
    config.rack_dev_mark.enable = !%w(env1 env2 env3).include?(Rails.env)
  end
end

Since Heroku uses production env for staging. You can't use the settings above. However, the gem provide an easier way to set it up on Heroku. Just set the environment variable on the environment in which you want to show the mark.

heroku config:set RACK_DEV_MARK_ENV=staging

That's it!

rack-dev-mark should be inserted before ActionDispatch::ShowExceptions becase we want to show the dev mark on the error pages as well. However, it does not work well if it's inserted by incorrect order with some other rack middlewares. So, it provides the setting of inserted place.

module MyApp
  class Application < Rails::Application
    config.rack_dev_mark.insert_before SomeOtherMiddleware
  end
end

config.rack_dev_mark.insert_after is also available to insert rack-dev-mark after a middleware.

Here is the compatibility list which many people often ask.

Set the custom env string maually.

module MyApp
  class Application < Rails::Application
    config.rack_dev_mark.env = 'foo'
  end
end

skip_rack_dev_mark controller helper works like around_filter.

class FooController < ApplicationController
  skip_rack_dev_mark only: [:iframe]

  def index
    # Do something
  end

  def iframe
    # Do something
  end
end

In this case, only index action will insert the dev mark.

Get i18n string with rack_dev_mark locale strings.

e.g. In config/locale/rack_dev_mark.ja.yml

ja:
  rack_dev_mark:
    development: '開発中'
    staging: 'ステージング'

Then, you will get translated string on the pages!

Although the default themes are title and github_fork_ribbon, you can create your own themes inheriting Rack::DevMark::Theme::Base.

require 'rack/dev-mark/theme/base'

class NewTheme < Rack::DevMark::Theme::Base
  def insert_into(html, env, params = {})
    # Do something for your theme
    html
  end
end

class AnotherTheme < Rack::DevMark::Theme::Base
  def insert_into(html, env, params = {})
    # Do something for your theme
    html
  end
end

Then, insert them in your app.

use Rack::DevMark::Middleware, [NewTheme.new, AnotherTheme.new]

In config/application.rb

module MyApp
  class Application < Rails::Application
    config.rack_dev_mark.theme = [NewTheme.new, AnotherTheme.new]
  end
end

You can add any combination of themes. See more about themes.

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

Copyright (c) 2014 Daisuke Taniwaki. See LICENSE for details.