Methods

Instance Public methods

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
📝 Source code 
# 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
🔎 See on GitHub

readonly_attributes()

Returns an array of all the attributes that have been specified as readonly.

📝 Source code 
# File activerecord/lib/active_record/readonly_attributes.rb, line 39
      def readonly_attributes
        _attr_readonly
      end
🔎 See on GitHub