Ruby variable scope: access rack.env from inside an existing ruby class?

Question

I have a simple class:

class Repository
  class << self
    def find(id)
      ...
    end
  end
end

It is called like this throughout our app:

 thing = Repository.find("abc")

We are in a Sinatra/rack environment. During the request phase we do something like this:

  env['org'] = 'acme'

What I'd like to do is be able to get access to 'acme' from inside the class Repository, without having to explicitly pass it in. There are so many calls to this class all over the place that it would be a pain to pass in the value each time through the find method e.g., find(id,org = nil). I thought maybe there's a way to include the rack gem in Repository, and get at it that way, but so far no luck. Global variables are out - has to be scoped to the request.

Is it possible to do something like this?

score 0 · Accepted Answer · answered Jul 06 '13 at 20:31

0

Personally, I think having a variable that changes like that inside a class method is asking for trouble, it breaks the Law of Demeter by reaching across boundaries. Instead, I'd wrap it in a Sinatra helper which then passes the second argument by default.

helpers do
  def find( s )
    Repository.find( s, env['org'] )
  end
end

and modify the Repository's find method to take the second argument.

answered Jul 06 '13 at 20:31

ian

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Yeah I pretty much ended up doing that. It was a lot of refactoring, but I agree that what I was trying to do as a shortcut up there was a total kludge. – Steve Macdonald Jul 07 '13 at 00:59

Ruby variable scope: access rack.env from inside an existing ruby class?

1 Answers1