What is the best way to convert all controller params from camelCase to snake_case in Rails?

Question

As you already know, JSON naming convention advocates the use of camelSpace and the Rails advocates the use of snake_case for parameter names.

What is the best way t

Answer 1

Solution for Rails 5

before_action :underscore_params!

def underscore_params!
  underscore_hash = -> (hash) do
    hash.transform_keys!(&:underscore)
    hash.each do |key, value|
      if value.is_a?(ActionController::Parameters)
        underscore_hash.call(value)
      elsif value.is_a?(Array)
        value.each do |item|
          next unless item.is_a?(ActionController::Parameters)
          underscore_hash.call(item)
        end
      end
    end
  end
  underscore_hash.call(params)
end