CSV Model Exporter Task

csv.rake

  namespace :csv do
    task :export, :model, :attributes, :scope, :needs => :environment do |task, args|
      raise ArgumentError, "Specify a model (e.g. rake sqoot:csv:export[User])" if args[:model].blank?

      model     = args[:model].constantize
      models    = model.send(args[:scope] || :all) # e.g. User.with_email || User.all
      file_name = "#{args[:model].tableize}#{'_' + args[:scope] if args[:scope]}.csv" # e.g. users_with_email.csv
      file      = File.join(Rails.root, 'tmp', file_name)
      columns   = args[:attributes].try(:split, ',') || model.send(:new).attributes.keys

      CSV.open(file, 'wb') do |csv|
        csv << columns
        models.each do |model_instance|
          csv << columns.collect { |c| model_instance.send(c) }
        end
      end

      # Not sure why, but it seems to be writing empty files to S3 (local seems OK)
      "#{Rails.env}/csv/#{Time.now.strftime('%Y_%m_%d_%H:%M')}_#{file_name}".tap do |path|
        S3Helper.copy(file, path)
        puts "Saved to S3 at: #{path}"
      end
    end
  end