Module: ActiveRecord::AttributeMethods::Read

Extended by:
ActiveSupport::Concern
Defined in:
lib/active_record/attribute_methods/read.rb

Defined Under Namespace

Modules: ClassMethods

Constant Summary collapse

ATTRIBUTE_TYPES_CACHED_BY_DEFAULT = 
[:datetime, :timestamp, :time, :date]

Instance Method Summary collapse

Instance Method Details

#read_attribute(attr_name) ⇒ Object

Returns the value of the attribute identified by attr_name after it has been typecast (for example, “2004-12-12” in a data column is cast to a date object, like Date.new(2004, 12, 12)).



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# File 'lib/active_record/attribute_methods/read.rb', line 75

def read_attribute(attr_name)
  attr_name = attr_name.to_s
  attr_name = self.class.primary_key if attr_name == 'id'
  value = @attributes[attr_name]
  unless value.nil?
    if column = column_for_attribute(attr_name)
      if unserializable_attribute?(attr_name, column)
        unserialize_attribute(attr_name)
      else
        column.type_cast(value)
      end
    else
      value
    end
  else
    nil
  end
end

#unserializable_attribute?(attr_name, column) ⇒ Boolean

Returns true if the attribute is of a text column and marked for serialization.

Returns:

  • (Boolean) 


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# File 'lib/active_record/attribute_methods/read.rb', line 95

def unserializable_attribute?(attr_name, column)
  column.text? && self.class.serialized_attributes[attr_name]
end

#unserialize_attribute(attr_name) ⇒ Object

Returns the unserialized object of the attribute.



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# File 'lib/active_record/attribute_methods/read.rb', line 100

def unserialize_attribute(attr_name)
  unserialized_object = object_from_yaml(@attributes[attr_name])

  if unserialized_object.is_a?(self.class.serialized_attributes[attr_name]) || unserialized_object.nil?
    @attributes.frozen? ? unserialized_object : @attributes[attr_name] = unserialized_object
  else
    raise SerializationTypeMismatch,
      "#{attr_name} was supposed to be a #{self.class.serialized_attributes[attr_name]}, but was a #{unserialized_object.class.to_s}"
  end
end