gistfile1.rb

class Event::InvitationsController < ApplicationController
  load_resource :event
  before_filter :authorize_resource

  def new; end

  def create
    unless params[:users_to_invite].blank?
      ids = { groups: [], users: [] }

      params[:users_to_invite].each do |user_identifier|
        table_name, id = user_identifier.split('.')
        if id.blank?
          ids[table_name.to_sym] = case table_name
                                   when 'users' then current_user.friend_ids
                                   when 'groups' then  current_user.joined_group_ids
                                   else nil
                                   end
        else
          ids[table_name.to_sym].push(id.to_i)
        end
      end

      inviter_id = current_user.id
      users_not_invited = [inviter_id] + @event.invitee_ids + @event.visitor_ids

      user_ids = (Group.participant_ids_for_groups(ids[:groups]) + ids[:users] - users_not_invited).uniq

      user_ids.each do |invitee_id|
        if User.find(invitee_id).profile.event_invitation?
          EventInvitation.create do |item|
            item.inviter_id = inviter_id
            item.invitee_id = invitee_id
            item.event = @event
          end
        end
      end
    end

    unless params[:emails_to_invite].blank?
      emails = ActiveSupport::JSON.decode(params[:emails_to_invite]).to_a.select do |email|
        user = User.find_by_email(email)
        (user.present? && user.profile.event_email_notification?) || user.blank?
      end

      emails.each do |email|
        EventMailer.invite(@event.id, @event.title, email.strip).deliver!
      end
    end

    redirect_to @event, notice: I18n.t('invitation.has_been_sent')
  end

  private

  def authorize_resource
    authorize! :update, @event
  end

end