How to define a method in ruby using splat and an optional hash at the same time? [duplicate]

Question

I am able to define a method like this:

def test(id, *ary, hash_params)
  # Do stuff here
end

But this makes the hash_params argument mandatory. These don't work either:

def t(id, *ary, hash_params=nil)  # SyntaxError: unexpected '=', expecting ')'
def t(id, *ary, hash_params={})   # SyntaxError: unexpected '=', expecting ')'

Is there a way to make it optional?

Answer 1

There is support for this in ActiveSupport through the use of the array extension extract_options!.

def test(*args)
  opts = args.extract_options!
end

If the last element is a hash, then it will pop it from the array and return it, otherwise it will return an empty hash, which is technically the same as what you want (*args, opts={}) to do.

ActiveSupport Array#extract_options!