From: Jarmo Pertman <jarmo.p@...>
Date: 2011-06-18T18:45:32+09:00
Subject: Re: how would you set dynamically determined dependencies with or without bundler?

After playing around a little i found this solution to be the one i
needed - in Gemfile:

platforms :mswin, :mingw do
  gem "win-specific-gem1"
  gem "win-specific-gem2"
end

gem "gem3" # works on all platforms

Now in my gem i just do require "win-specific-gemX" if the OS is win
and on other's require "gem3". If there's any better solution then let
me know of course :)

Jarmo Pertman
-----
IT does really matter - http://www.itreallymatters.net

On Jun 18, 10:21 am, Jarmo Pertman <jarm...@gmail.com> wrote:
> Hi!
>
> I have developing a gem where some of it's dependencies are not
> in .gemspec since they can be different depending of the value of
> environment variable, class variable or just depending of the OS in
> use. In short, these dependencies expose the same API, but can be
> switched during runtime before actually loading the gem itself. The
> gem then does something in the lines of:
> require "rubygems"
> gem "dependency", "version"
> require "dependency"
>
> depending of some criteria as written above. Now when using Bundler
> with it's Bundler.setup invocation, what should be in Gemfile so it
> would work the same on every configuration without having to have
> modified Gemfile and Gemfile.lock on each different machine.
>
> Can i have different "gem" lines in Gemfile on different machines and
> commit it actually into VCS without having to modify it on each and
> every machine separately?
>
> Something in the Gemfile like this would work perfectly?
> if RUBY_PLATFORM =~ /mswin|msys|mingw32/
>   gem "dep1"
> else
>   gem "dep2"
> end
>
> In that case "dep1" and "dep2" would end up in Gemfile.lock - is it
> okay, even if dep1 is not installable on unix platform?
>
> Jarmo Pertman
> -----
> IT does really matter -http://www.itreallymatters.net