First Call to a Controller, Constant is defined, Second call, “uninitialized constant Oauth”?

问题

I am trying to get the OAuth gem to work with Rails 3 and I'm running into this weird problem... (independent of the gem, I think I've run into this once before)

I have a controller called "OauthTestController", and a model called "ConsumerToken". The model looks like this.

require 'oauth/models/consumers/token'
class ConsumerToken < ActiveRecord::Base
  include Oauth::Models::Consumers::Token
end

When I go to "/oauth_test/twitter", it loads the Oauth::Models::Consumers::Token module and I'm able to connect to twitter no problem. But the second time I try it (just refresh the /oauth_test/twitter url), it gives me this error:

NameError (uninitialized constant Oauth):
  app/models/consumer_token.rb:4
  app/models/twitter_token.rb:2
  app/controllers/oauth_test_controller.rb:66:in `load_consumer'

Why is that? It has something to do with load paths or being in development mode maybe?

回答1:

Try using require_or_load instead of require. That forces full load each time when in development and can sometimes help with this sort of issue.

回答2:

Yeah it's something to do with being in development mode. Setting config.cache_classes = true in your development.rb get's it working (but is a pain in the ass)

来源：https://stackoverflow.com/questions/2796465/first-call-to-a-controller-constant-is-defined-second-call-uninitialized-con