instance method `becomes`

Ruby on Rails 8.1.2

Since v3.0.20

Available in: v3.0.20 v3.1.12 v3.2.22.5 v4.0.13 v4.1.16 v4.2.9 v5.2.8.1 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

becomes(klass)

Returns an instance of the specified klass with the attributes of the current record. This is mostly useful in relation to single table inheritance (STI) structures where you want a subclass to appear as the superclass. This can be used along with record identification in Action Pack to allow, say, Client < Company to do something like render partial: @client.becomes(Company) to render that instance using the companies/company partial instead of clients/client.

Note: The new instance will share a link to the same attributes as the original class. Therefore the STI column value will still be the same. Any change to the attributes on either instance will affect both instances. This includes any attribute initialization done by the new instance.

If you want to change the STI column as well, use #becomes! instead.

Parameters

klass req

Source

# File activerecord/lib/active_record/persistence.rb, line 487
    def becomes(klass)
      became = klass.allocate

      became.send(:initialize) do |becoming|
        @attributes.reverse_merge!(becoming.instance_variable_get(:@attributes))
        becoming.instance_variable_set(:@attributes, @attributes)
        becoming.instance_variable_set(:@mutations_from_database, @mutations_from_database ||= nil)
        becoming.instance_variable_set(:@new_record, new_record?)
        becoming.instance_variable_set(:@previously_new_record, previously_new_record?)
        becoming.instance_variable_set(:@destroyed, destroyed?)
        becoming.errors.copy!(errors)
      end

      became
    end

Defined in activerecord/lib/active_record/persistence.rb line 487 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveRecord::Persistence

Signature

Parameters