instance method `attr_readonly`

Ruby on Rails 8.1.2

Since v3.2.22.5

Available in: 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:

attr_readonly(*attributes)

Attributes listed as readonly will be used to create a new record. Assigning a new value to a readonly attribute on a persisted record raises an error.

By setting config.active_record.raise_on_assign_to_attr_readonly to false, it will not raise. The value will change in memory, but will not be persisted on save.

Examples

class Post < ActiveRecord::Base
  attr_readonly :title
end

post = Post.create!(title: "Introducing Ruby on Rails!")
post.title = "a different title" # raises ActiveRecord::ReadonlyAttributeError
post.update(title: "a different title") # raises ActiveRecord::ReadonlyAttributeError

Parameters

attributes rest

Source

# File activerecord/lib/active_record/readonly_attributes.rb, line 30
      def attr_readonly(*attributes)
        self._attr_readonly |= attributes.map(&:to_s)

        if ActiveRecord.raise_on_assign_to_attr_readonly
          include(HasReadonlyAttributes)
        end
      end

Defined in activerecord/lib/active_record/readonly_attributes.rb line 30 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveRecord::ReadonlyAttributes::ClassMethods

Signature

Examples

Parameters