Non persistent ActiveRecord model attributes

Question

I want to add to an existing model some attributes that need not be persisted, or even mapped to a database column. Is there a solution to specify such thing ?

Answer 1

In case anyone is wondering how to render this to the view, use the method arguments for the render method, like so:

render json: {results: results}, methods: [:my_attribute]

Please know that this only works if you set the attr_accessor on your model and set the attribute in the controller action, as the selected answer explained.