Method: ActiveRecord::Persistence::ClassMethods#instantiate

Defined in:

activerecord/lib/active_record/persistence.rb

#instantiate(attributes, column_types = {}, &block) ⇒ Object

Given an attributes hash, instantiate returns a new instance of the appropriate class. Accepts only keys as strings.

For example, Post.all may return Comments, Messages, and Emails by storing the record’s subclass in a type attribute. By calling instantiate instead of new, finder methods ensure they get new instances of the appropriate class for each record.

See ActiveRecord::Inheritance#discriminate_class_for_record to see how this “single-table” inheritance mapping is implemented.

# File 'activerecord/lib/active_record/persistence.rb', line 100

def instantiate(attributes, column_types = {}, &block)
  klass = discriminate_class_for_record(attributes)
  instantiate_instance_of(klass, attributes, column_types, &block)
end