Currency model of cryptoLineBot https://github.com/roger35972134/cryptoLineBot

Currency.rb

class Currency < ActiveRecord::Base

  require 'open-uri'
  def self.get_currency
    begin
      books = Nokogiri::HTML(open("https://www.coingecko.com/en"))
      name = []
      abbreviation = []
      rate = []
      exchange = []

      books.css('.coin-content-name').each do |link|
        name.push link.content
      end

      books.css('.coin-crypto-symbol').each do |link|
        abbreviation.push link.content
      end
      
      books.css('.stat-percent').each do |link|
        rate.push link.content
      end

      books.css('.currency-exchangable').each do |link|
          s = link.content.split("\n")[1]
          exchange.push s
      end

      (0..name.count-1).each do |i|
        currency = Currency.find_by(:name => name[i])
        currency = Currency.create(:name => name[i]) if currency.nil?

        currency.abbreviation = abbreviation[i]
        currency.value = exchange[i*3]
        currency.rate = rate[i]
        currency.market_exchange = exchange[i*3+2]
        currency.save
      end
    rescue OpenURI::HTTPError => e
      return "Server Error"
    end

    return "OK"
  end

  def self.search_by_abbreviation(abbreviation)
    if get_currency == "OK"
      c = Currency.find_by(:abbreviation => abbreviation)

      unless c.nil?
        res = "貨幣: #{c.name}\n價格: #{c.value}\n市場價值: #{c.market_exchange}"
      else
        res = "請輸入正確的貨幣代號，例如：BTC (Bitcoin)!"
      end
    else
      res = "伺服器目前維護中...\n請稍候再試，謝謝您的支持(oops)"
    end
    res
  end
end