XLS Import end export

data_manipulation.rb

class DataManipulation
  include ActiveModel::Conversion
  extend ActiveModel::Naming
  ALLOWED_MODELS = [:products, :stores]
  
  attr_accessor :file, :model_name
  
  def initialize(options = {})
    self.file = options[:file]
    self.model_name = options[:model_name].try(:singularize)
  end
  
  def process
    self.records.each do |record|
      begin
        if record[:id].present?
          item = model_name.classify.constantize.find(record[:id].to_i)
          item.update_attributes(record)
          item.save
        else
          raise ActiveRecord::RecordNotFound
        end
      rescue
        item = model_name.classify.constantize.create(record)
      end
    end
    return true
  end
  
  def records
    headers = nil
    rows = []
    spreadsheet = Spreadsheet.open(self.file.path)
    unless spreadsheet.worksheets.empty? 
      spreadsheet.worksheets.first.each do |row|
        if headers.nil?
          headers = row.collect{|field| field.parameterize('_').strip}
          d headers
        else
          rows << Hash[headers.zip(row.collect{|field| field.to_s.strip })].symbolize_keys
        end
      end
    end
    return rows
  end
  
  
  def persisted?
    false
  end
end

data_manipulations_controller.rb

class Admin::DataManipulationsController < Admin::AdminController
  def show
    model_name = params[:id].to_s
    if DataManipulation::ALLOWED_MODELS.include? model_name.to_sym
      Mime::Type.register "application/vnd.ms-excel", :xls
      @records = model_name.classify.constantize.all
      columns = model_name.classify.constantize.column_names
      send_data  @records.to_xls(:only => columns.select{|name| not name =~ /(updated|created)_at/})
    else
      render :file => "#{Rails.root}/public/404.html", :status => 404
    end
  end
  
  def index
    @data_manipulation = DataManipulation.new()
  end
  
  def create
    @data_manipulation = DataManipulation.new(params[:data_manipulation])
    if @data_manipulation.process
      redirect_to admin_data_manipulations_path, :notice => 'Elaborazione completata con successo!'
    else
      render :action => :index
    end
  end
  
end