Now when confirmation validations fail, the error will be attached to :#{attribute}_confirmation instead of attribute.

(written by lawrence krubner, however indented passages are often quotes). You can contact lawrence at: lawrence@krubner.com, or follow me on Twitter.

Upgrading to Rails 4. I am not sure what this means, so I will leave this note to myself, and come back and read more later.

5.6 Active Model

Rails 4.0 has changed how errors attach with the ActiveModel::Validations::ConfirmationValidator. Now when confirmation validations fail, the error will be attached to :#{attribute}_confirmation instead of attribute.

Rails 4.0 has changed ActiveModel::Serializers::JSON.include_root_in_json default value to false. Now, Active Model Serializers and Active Record objects have the same default behavior. This means that you can comment or remove the following option in the config/initializers/wrap_parameters.rb file:

# Disable root element in JSON by default.
# ActiveSupport.on_load(:active_record) do
# self.include_root_in_json = false
# end

Post external references

  1. 1
    http://edgeguides.rubyonrails.org/upgrading_ruby_on_rails.html
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