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

ActiveSupport already provides a String#snakecase method. All you have to do is install a filter that does a deep iteration through the params hash and replaces the keys with key.snakecase.

before_filter :deep_snake_case_params!

def deep_snake_case_params!(val = params)
  case val
  when Array
    val.map {|v| deep_snake_case_params! v }
  when Hash
    val.keys.each do |k, v = val[k]|
      val.delete k
      val[k.snakecase] = deep_snake_case_params!(v)
    end
    val
  else
    val
  end
end