Getting started with Nokogiri in Rails? No need for gem 'nokogiri'?

Question

I'm just looking into Nokogiri and was thinking about using it in my app, but apparently when I do bundle install (without gem 'nokogiri' ) it's already " Using nokogiri 1.6.7.1 ".

When I add gem 'nokogiri' in my Gemfile, there's no "installing..." So, is nokogiri already pre installed in Rails? If so, do I still have to require these:

require 'nokogiri'
require 'open-uri'

Where do I put this? Within my controller? or application.rb ?

This is my application.rb looks like

require File.expand_path('../boot', __FILE__)

require 'rails/all'

Bundler.require(*Rails.groups)

if Rails.env.test? || Rails.env.development?
  CONFIG = YAML.load(File.read(File.expand_path('../aws.yml', __FILE__)))
  CONFIG.merge! CONFIG.fetch(Rails.env, {})
  CONFIG.symbolize_keys!
end

module App
  class Application < Rails::Application
    config.middleware.use Rack::Pjax
    config.active_record.raise_in_transactional_callbacks = true
    config.active_job.queue_adapter = :sidekiq
  end
end

Answer 1

Nokogiri is required by another gem ( rails-dom-testing ). So it's already installed.

And you don't need to write require 'nokogiri' statement. Because Rails uses Bundler to manage dependencies and load gems. Nokogiri will be already loaded.