Using local gems

Rails
1

Hello,

I have successfully installed some local gems on my rails host. I
checked that through irb:

irb(main):002:0> require ‘rubygems’
=> true
irb(main):003:0> require_gem ‘mylocalgem’
=> true
irb(main):003:0> a = MyLocalGem::MyClass.new
=> #<MyLocalGem::MyClass:0x409a343c [bunch of stuff from MyClass]>

I’m still unable to make my rails application use that gem.

config/environment.rb (at the end):
ENV[‘GEM_PATH’] = ‘/usr/lib/ruby/gems/1.8:/my/path/to/local/gems’

app/helpers/application_helper.rb:
require ‘rubygems’
require_gem ‘mylocalgem’
module ApplicationHelper
end

app/controllers/user_controller.rb:
[…]
def show_myclass
@myclass = MyLocalGem::MyClass.new
end
[…]

And when I browse to /user/show_myclass, I get:
NameError in UserController#show_myclass
uninitialized constant UserController::MyLocalGem
#{RAILS_ROOT}/app/controllers/user_controller.rb:265:in
`show_myclass’

What did I miss?

Thanks,
Karine

2

Hi Karine

How about installing Aptana Radrails, there is a GEM manager for you
to use.

3

On 2 Oct 2007, at 10:52, edhel wrote:

I’m still unable to make my rails application use that gem.

config/environment.rb (at the end):
ENV[‘GEM_PATH’] = ‘/usr/lib/ruby/gems/1.8:/my/path/to/local/gems’

app/helpers/application_helper.rb:
require ‘rubygems’
require_gem ‘mylocalgem’
module ApplicationHelper
end

ApplicationHelper is really not for that. it’s probably not even
loaded at the point your show_myclass action is called.
Stick your require_gem ‘mylocalgem’ in environment.rb

Fred

4

On Oct 2, 12:05 pm, CCH [email protected] wrote:

How about installing Aptana Radrails, there is a GEM manager for you
to use.

I only have SSH access to that host, sorry.

Karine

5

On 2 Oct 2007, at 11:39, edhel wrote:

ApplicationHelper is really not for that. it’s probably not even
loaded at the point your show_myclass action is called.
Stick your require_gem ‘mylocalgem’ in environment.rb

OK, thanks for that good practice information, though it did not fix
the problem.

You might need the ENV[‘GEM_PATH’] stuff before rubygems is required.
have you tried doing export GEM_PATH=foo in a shell before starting
the mongrels (or whatever it is you’re using) ?

Is it still throwing an uninitalized constant error or is the require
itself failing ? If the require isn’t failing then it’s probably
nothing to do with where the gem is etc…

Fred

6

On Oct 2, 12:49 pm, Frederick C. [email protected]
wrote:

You might need the ENV[‘GEM_PATH’] stuff before rubygems is required.

Wow, indeed, that was so obvious I’m ashamed I didn’t think about it.
The problem is still there though.

have you tried doing export GEM_PATH=foo in a shell before starting
the mongrels (or whatever it is you’re using) ?

I’m not starting anything, my host has its webserver configured
properly to serve rails apps. GEM_PATH is in my .bash_profile, which
may have helped irb to find the gem, but I’m surprised ENV[‘GEM_PATH’]
in environment.rb is not enough to make it work for the rails app.

Is it still throwing an uninitalized constant error or is the require
itself failing ? If the require isn’t failing then it’s probably
nothing to do with where the gem is etc…

Yes, still the same unitialized constant error.

Thanks for trying to nail down the issue, I guess I will have to ask
my host if they have any specific config that causes this problem…

Karine

7

On 2 Oct 2007, at 12:08, edhel wrote:

have you tried doing export GEM_PATH=foo in a shell before starting
the mongrels (or whatever it is you’re using) ?

I’m not starting anything, my host has its webserver configured
properly to serve rails apps. GEM_PATH is in my .bash_profile, which
may have helped irb to find the gem, but I’m surprised ENV[‘GEM_PATH’]
in environment.rb is not enough to make it work for the rails app.

Surely there is something you can start or restart: if you don’t
restart whatever is picking up your rails code then it won’t pick up
changes to environment.rb
It’s entirely possible .bash_profile only read when a shell is
invoked, and not in other cases (I can never remember the difference
between all those files)

Fred

8

On Oct 2, 1:16 pm, Frederick C. [email protected]
wrote:

Surely there is something you can start or restart: if you don’t
restart whatever is picking up your rails code then it won’t pick up
changes to environment.rb

Well done! I killed the running dispatch.fcgi processes, a new one was
spawned and the config files re-read. Everything is working fine now,
many thanks :slight_smile:

Karine

9

On Oct 2, 12:20 pm, Frederick C. [email protected]
wrote:

app/helpers/application_helper.rb:
require ‘rubygems’
require_gem ‘mylocalgem’
module ApplicationHelper
end

ApplicationHelper is really not for that. it’s probably not even
loaded at the point your show_myclass action is called.
Stick your require_gem ‘mylocalgem’ in environment.rb

OK, thanks for that good practice information, though it did not fix
the problem.

I should note the same rails app is working fine on my development
server, where the gem is installed in /usr/lib… (and I only need
“require ‘mylocalgem’” to make it work, of course). So it’s really a
configuration problem involving gems installed in a local prefix.

Karine