geekmade

Ruby hash keys can be any type of object apart from an integer, but typically they are used in two ways when coding a rails app.

With string keys:

{"a" => "hash"}

Or symbol keys:

{:a => "hash"}

When writing a method that uses a hash of arguments you should handle both styles of hashes. There are a number of reasons for this.

• You work with other developers who have different coding styles and use either method.
• More flexibility to fit with other bits of code.
• Cover more bases and its less likely to break.
• Generally a good design decision.

The easiest way to handle this situation is to normalize all the keys to symbols and Rails provides the symbolize_keys and symbolize_keys! in ActiveSupport for your coding pleasure.

The symbolize_keys method itself is useful to include in standalone ruby scripts and libraries, also its a good example of how to use Enumerable#inject for more complex stuff.

def symbolize_keys
  inject({}) do |options, (key, value)|
    options[(key.to_sym rescue key) || key] = value
    options
  end
end

A small tip that has come in handy on a few occasions.