Comments on: Adventures in Ruby: When Constants Aren’t

By: Dan Kubb

Dan Kubb — Tue, 17 Nov 2009 04:44:06 +0000

One thing I’d recommend is using freeze on the constant when you define it, eg:

SERVICE_URL = ‘http://accountingservice.com/’.freeze

That way at least you won’t append to it accidentally. You’ll be forced to clone it, or come up with other ways of using it that don’t involve modifying it.

By: Nick Hoffman

Nick Hoffman — Mon, 16 Nov 2009 20:27:33 +0000

Ah true, you did say that the posted code was a simplified example =P

By: Enrico

Enrico — Mon, 16 Nov 2009 18:29:12 +0000

I have a lot more parameters than that to append; there are up to six in my code right now. That’d make for a considerably long line. I might be able to clean it up by using string interpolation, however:

def transaction_url
“#{SERVICE_URL}VAL1=#{value1}&VAL2=#{value2}…”
end

EDIT: …or, you know, I could just break it into multiple lines. =P

By: Nick Hoffman

Nick Hoffman — Mon, 16 Nov 2009 18:26:32 +0000

I was bitten by this bug a few months ago, actually. It was annoying, but it definitely taught me (and you, obviously) about some of the innards of Ruby constants.

Rather than cloning SERVICE_URL, why not just do this?:

def transaction_url
SERVICE_URL + ‘VAL1=foo’ + ‘&VAL2=bar’
end