Allow serialized attributes with unknown keys to be permitted in strong parameters.

Suppose that, we have Attempt model and we have serialized an attribute in attempt.rb like this

class Attempt < ApplicationRecord

 #==== Serializations ==================
   serialize :response

 end

Now, if you are creating attempt through strong parameters in controller -

   
   

Attempt.create(attempts_params)

And you have permitted response attribute in strong parameters like this

 def attempts_params
     params.require(:attempt).permit(:response)
 end

        OR

   

 def attempts_params
     params.require(:attempt).permit(:response => {})
 end

Above strong parameters will save response as nil or blank. In this scenario we have to permit keys of serialized attributes in strong parameter

 def attempts_params
     response_keys = params[:attempt][:response].keys
     params.require(:attempt).permit(response: response_keys)
 end