admin_controller.rb

def index
  if current_user.admin
    @stocks = Stock.all
  else
    redirect_to root_path
    flash[:error] = "You must be an administrator to access this page!"
  end
end

admin_stock_controller.rb

class Admin::StocksController < AdminController

  def create
  end

  def destroy
    if Stock.find(params[:id]).destroy
      redirect_to admin_panel_path, :notice => "Stock successfully removed!"
    else
      redirect_to admin_panel_path
      flash[:error] = "failed to remove stock!"
    end
  end

  def update_multiple
    if params[:commit] == "Update selected" && !params[:selected].nil?
      number_of_updated_quotes = pluralize(params[:selected].count, "quote")
      process_updates
      redirect_to admin_panel_path
      flash[:notice] = "Updated #{number_of_updated_quotes}."
    elsif params[:commit] == "Remove selected" && !params[:selected].nil?
      number_of_removed_stocks = pluralize(params[:selected].count, "stock")
      remove_multiple
      redirect_to admin_panel_path
      flash[:alert] = "Removed #{number_of_removed_stocks}."
    else
      redirect_to admin_panel_path
      flash[:info] = "Select something first."
    end
  end

  def edit
  end

  def new
    @symbol_list = params[:symbol].split(",").map{ |s| s.strip }
    if @symbol_list.any?
      YahooFinanceIntegrator.new @symbol_list
      number_of_added_stocks = pluralize(@symbol_list.count, 'Stock')
      redirect_to admin_panel_path, :notice => "Added #{number_of_added_stocks}"
    else
      redirect_to admin_panel_path
      flash[:error] = "Didn\'t find any symbols. Was the text area empty? ;-)"
    end
  end

  def update
    @symbol_list = Array.new
    stocks = Stock.all
    stocks.each do |stock|
      @symbol_list << stock.symbol
    end
    YahooFinanceIntegrator.get_quotes(@symbol_list)
    redirect_to admin_panel_path, :notice => "Stocks successfully updated!"
  end

  def pluralize(count, singular, plural = nil)
    "#{count || 0} " + ((count == 1 || count =~ /^1(\.0+)?$/) ? singular : (plural || singular.pluralize))
  end

  protected
  def remove_multiple
    Stock.destroy_all(["stocks.id IN (?)", params[:selected].keys] ) if params[:selected].any?
  end
  protected :remove_multiple

  def process_updates
    YahooFinanceIntegrator.new( params[:selected].keys ) if params[:selected].any?
  end
end

yahoo_finance_integrator.rb

class YahooFinanceIntegrator
  attr_accessor :stocks, :quotes

  def initialize array
    if verify array
      add_quote_for_new_stock array
    else
      verify array
    end
  end

  def verify array
    raise "Must have something to integrate!" if array.nil?
    raise "Must pass in an actual array list of symbol strings!" unless array.is_a?(Array)
    raise "The list must not be empty!" if array.empty?
    true
  end

  def get_quotes array
    y_ext_hsh = YahooFinance.get_extended_quotes array
    y_std_hsh = YahooFinance.get_standard_quotes array
    y_ext_hsh.keys.each do |symbol|
      symbol.inspect
      co_name = y_ext_hsh[symbol].name
      stock = Stock.find_or_create_by_symbol_and_company_name(symbol, co_name)
      puts stock.nil?
      stock.update_attributes( :company_name        => co_name,
                               :symbol              => y_ext_hsh[symbol].symbol )
      Quote.create(            :ex_dividend_date    => y_ext_hsh[symbol].exDividendDate,
                               :dividend_pay_date   => y_ext_hsh[symbol].dividendPayDate,
                               :dividend_yield      => y_ext_hsh[symbol].dividendYield,
                               :dividends_per_share => y_ext_hsh[symbol].dividendPerShare,
                               :last_price          => y_std_hsh[symbol].lastTrade,
                               :stock               => stock
                             )
    end
  end

  def add_quote_for_new_stock(array)
    @symbol_list = Array.new
    array.each do |symbol|
      @symbol_list << symbol
      #Stock.create( :symbol => symbol, :company_name => "new_company" )
    end
    get_quotes(@symbol_list)
  end
end