A small scraper for the list of attendees on http://barcampstockholm.com/

barcamp_stockholm_scraper.rb

require 'open-uri'
require 'nokogiri'

module BarCampStockholm
  class << self

    def url
      'http://barcampstockholm.com/'
    end

    def scrape
      doc = Nokogiri::HTML(open(url))

      @companies = { nil => Company.new('Okänt') }

      @attendees = doc.css('.attendees li').map do |li|
        name, company = li.text.strip.split(', ')
        Attendee.new name, @companies[company] ||= Company.new(company)
      end
    end

    def attendees
      @attendees || scrape
    end

    def companies
      @companies || scrape && @companies
    end

    def all(filter = //)
      attendees.select { |a| a.name.match filter }
    end

    def one(filter = //)
      all(filter).sample
    end
  end

  class Attendee
    attr_accessor :name, :company

    def initialize(name, company)
      @name    = name
      @company = company

      company << self
    end

    def inspect
      "#{name}, #{company}"
    end
  end

  class Company
    attr_accessor :name, :attendees

    def initialize(name)
      @name      = name
      @attendees = []
    end

    def <<(attendee)
      @attendees << attendee
    end

    def size
      attendees.size
    end

    def to_s
      name
    end

    def inspect
      to_s
    end
  end
end

Usage

# All of the attendees
BarCampStockholm.attendees

# All attendees with a last name that ends in "berg"
BarCampStockholm.all /berg$/

# All of the companies
BarCampStockholm.companies

# Companies grouped by number of attendees
BarCampStockholm.companies.values.map.with_object({}) do |c,o|
  o[c.size] ||= []
  o[c.size] << c
end

# The company name for one of the Martins
BarCampStockholm.one('Martin').company.name