Update deep_symbolize_keys is in rails 4

Could not find it elsewhere, so here it is: recursive_symbolize_keys, that will symbolize all keys inside a hash and its nested hashes.

Hash extension

class Hash
  def recursive_symbolize_keys!
    symbolize_keys!
    # symbolize each hash in .values
    values.each{|h| h.recursive_symbolize_keys! if h.is_a?(Hash) }
    # symbolize each hash inside an array in .values
    values.select{|v| v.is_a?(Array) }.flatten.each{|h| h.recursive_symbolize_keys! if h.is_a?(Hash) }
    self
  end
end

Or standalone

  def recursive_symbolize_keys! hash
    hash.symbolize_keys!
    hash.values.select{|v| v.is_a? Hash}.each{|h| recursive_symbolize_keys!(h)}
  end