Formatting a possibly nil value as hours and minutes

Question

This might be a bit silly because there are like a thousand ways to do this, but I'm struggling to come up with one that I like. I feel like this should fit in one line, but I don't like re-using read_attribute(:length) lots and I don't like the below because it's not that clear.

# returns a human-readable string in the format Xh Ym
def length
  # length stored in seconds
  len = read_attribute(:length)
  "#{(len/60/60).floor}h #{len.modulo(60*60)/60}m" unless len.nil?
end

Answer 1

In one line

def length
  (len = read_attribute(:length)) && "#{(len/60/60).floor}h #{len.modulo(60*60)/60}m"
end

If len == nil return nil, if not - second operand

Answer 2

One-liners are nice, but sometimes it's better just to split lines. For example:

def length
  if (len = read_attribute(:length))
    "#{(len/60/60).floor}h #{len.modulo(60*60)/60}m" 
  end
end

If you really like compact code that deals with nil values, you can work with the idea of maybe's ick:

def length
  read_attribute(:length).maybe { |len| "#{(len/60/60).floor}h #{len.modulo(60*60)/60}m" }
end

Answer 3

Assuming that len is an integer you won't need to use floor. You can do something like this

"#{len/3600}h #{(len/60) % 60}m" unless len.nil?