instance method read_value_from_parameter

# File activerecord/lib/active_record/attribute_assignment.rb, line 148
    def read_value_from_parameter(name, values_hash_from_param)
      klass = (self.class.reflect_on_aggregation(name.to_sym) || column_for_attribute(name)).klass
      if values_hash_from_param.values.all?{|v|v.nil?}
        nil
      elsif klass == Time
        read_time_parameter_value(name, values_hash_from_param)
      elsif klass == Date
        read_date_parameter_value(name, values_hash_from_param)
      else
        read_other_parameter_value(klass, name, values_hash_from_param)
      end
    end