Rails 3: Generate unique codes (coupons)

Question

What\'s the best way to generate unique codes to use as coupon codes?

Thanks.

Answer 1

Note: There is a same question

Recently I wrote coupon-code gem that does exactly the same thing. The algorithm borrowed from Algorithm::CouponCode CPAN module.

A coupon code should not only be unique, but also easy to read and type while it still is secure. Neil's explanation and solution is great. This gem provides a convenient way to do it and a bonus validation feature.

>> require 'coupon_code'
>> code = CouponCode.generate
=> "1K7Q-CTFM-LMTC"
>> CouponCode.validate(code)
=> "1K7Q-CTFM-LMTC"
>> CouponCode.validate('1K7Q-CTFM-LMTO') # Invalid code
=> nil