Using Celluloid futures to make concurrent HTTP requests

celluloid_futures_json_request.rb

require "open-uri"
require 'json'
require 'celluloid/autostart'

def json(url)
  JSON.parse(open(url, 'Authorization' => 'Bearer API TOKEN').read)
end

class Resource
  
  def initialize(url)
    @url = url
    @future = Celluloid::Future.new { json(@url) }
    # @future = json(@url)
  end

  def links
    document['items'].map {|pr| pr['links']['self']['href']}
  end

  def title
    document['properties']['title']
  end
  
  def description
    document['properties']['description']
  end

  private
  
  def document
    @future.value
  end
end

class Index

  def initialize(url)
    @resource = Resource.new(url)
  end

  def urls
    @resource.links
  end
end

class Crawler
  def initialize(index)
    @index = index
  end

  def crawl
    resources.each do |page|
      Outputter.new(page).output
    end
  end

  private

  def resources
    @index.urls.map do |url|
      # future { Resource.new(url).get }
      Resource.new(url)
    end
  end
end

require "highline"

class Outputter
  OUTPUT_WIDTH = 79

  def initialize(page)
    @page = page
  end

  def output
    highline.say("-" * OUTPUT_WIDTH)
    highline.say(@page.title)
    highline.say("-" * OUTPUT_WIDTH)
    highline.say("\n\n")
  end

  private

  def highline
    @highline ||= HighLine.new($stdin, $stdout, OUTPUT_WIDTH)
  end
end

Crawler.new(Index.new("https://api.bootic.net/v1/products.json")).crawl