gistfile1.rb

module SoftDelete

  def destroy
    unless self.respond_to? :deleted_at
      raise MissingMigrationException
    end

    self.update_attribute :deleted_at, Time.now

    run_callbacks :destroy if self.is_a?(Performer)

    freeze
  end

  def restore
    unless self.deleted_at.nil?
      self.update_attribute :deleted_at, nil
    end
    
    restore_associations

  end

  def delete
    self.destroy
  end

  private
    def restore_associations
      self.class.reflect_on_all_associations.each do |reflection|
        macro = reflection.macro
        restorer_class = "Restore#{macro.to_s.camelize}".constantize
        restorer = restorer_class.new(self, reflection.name)
        restorer.restore if reflection.name.to_s.eql?("user")
      end
    end

end

class Restore

  def initialize(parent_model, model_name)
    @parent_model = parent_model
    @model_name = model_name.to_s
  end

  def restore
    objects = load_objects
    objects.each do |object|
      object.restore unless (object.nil? or !object.class.ancestors.include?(SoftDelete))
    end
  end

  protected
    def load_objects
      @parent_model.send(@model_name)
    end

end

class RestoreHasOne < Restore

  def initialize(parent_model, model_name)
    @parent_model = parent_model
    @model_name = model_name.to_s.singularize
  end

  def restore
    object = load_objects
    object.restore unless (object.nil? or !object.class.ancestors.include?(SoftDelete))
  end

end

class RestoreHasMany < Restore; end
class RestoreHasAndBelongsToMany < Restore; end
class RestoreBelongsTo < RestoreHasOne; end

class MissingMigrationException < Exception
  def message
    "Model requires a deleted_at timestamp field"
  end
end

class NotDeletedException < Exception
  def message
    "Object has not been deleted"
  end
end

class NotSoftDeleteableException < Exception
  def message
    "Model is not soft deleteable"
  end
end