canvas-lms/app/models/tableless.rb

#
# Copyright (C) 2011 Instructure, Inc.
#
# This file is part of Canvas.
#
# Canvas is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, version 3 of the License.
#
# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.
#

# allows you to have models that do not have database tables
# concept pulled from the comments of this page:
# http://stackoverflow.com/questions/937429/activerecordbase-without-table-rails
class Tableless < ActiveRecord::Base
  attr_accessible

  def self.columns
    @columns ||= [];
  end

  def self.column(name, sql_type = nil, default = nil, null = true)
    columns << ActiveRecord::ConnectionAdapters::Column.new(name.to_s, default,
      sql_type.to_s, null)
  end

  # Override the save method to prevent exceptions.
  def save(validate = true)
    validate ? valid? : true
  end
  
  def self.tableless?
    true
  end

  def self.find_by_sql(*args); []; end
  def self.count_by_sql(*args); 0; end
  def self.delete_all(*args); end
  def self.update_all(*args); end
  def self.execute_simple_calculation(*args); end
  def self.execute_grouped_calculation(*args); end
end