How do I rewrite Objective C options bitmasks to to Ruby for RubyMotion?

Question

How do I rewrite:

NSUInteger options = kCFCalendarUnitYear | kCFCalendarUnitMonth | kCFCalendarUnitDay;

To Ruby for Rubymotion?

Thanks :)

Answer 1

Almost the exact same way. The only difference really is that since Ruby requires constants to start with a capital letter, you must use a capital K instead:

options = KCFCalendarUnitYear | KCFCalendarUnitMonth | KCFCalendarUnitDay
# returns 28, same as in Objective-C.

Answer 2

Dylan Markow's answer is correct. Sometimes you might also want to create a bitmask from an array of values programmatically and you don't have the luxury of using the bitwise or operator directly.

For instance:

options = []
options << KCFCalendarUnitYear
options << KCFCalendarUnitMonth
options << KCFCalendarUnitDay

A nice little trick here is to use inject like so:

options.inject(:|)

It has the added advantage of looking like the face of a monkey.