In my rails3 engine gemfile, I added:
gem 'paperclip'
gem 'inherited_resources'
I also added this to my gemspec:
s.add_d开发者_运维百科ependency "paperclip"
s.add_dependency "inherited_resources"
I then ran bundle install for both my engine and the client app and started up the console for the client app in order to first test paperclip, to which I get:
Using /Users/ynkr/.rvm/gems/ruby-1.9.2-p180 with gemset rails31beta
ynkr % rails c
/Users/ynkr/.rvm/gems/ruby-1.9.2-p180@rails31beta/gems/actionpack-3.1.0.rc4/lib/action_dispatch/http/mime_type.rb:101: warning: already initialized constant YML
Loading development environment (Rails 3.1.0.rc4)
ruby-1.9.2-p180 :001 > b=Blog::Blog.first
Blog::Blog Load (0.2ms) SELECT `blogs`.* FROM `blogs` LIMIT 1
=> #<Blog::Blog id: 1, user_id: 1, context_id: 2, title: "Cmd Line Blog Title", title_for_url: "cmd-line-blog-title", teaser: "This is the teaser for the command line blog", content: "Some content for the cmd line blog", created_at: "2011-06-28 06:06:55", updated_at: "2011-06-28 06:06:55">
ruby-1.9.2-p180 :002 > b.photos
NoMethodError: undefined method `has_attached_file' for #<Class:0x00000102a57fc8>
from /Users/ynkr/.rvm/gems/ruby-1.9.2-p180@rails31beta/gems/activerecord-3.1.0.rc4/lib/active_record/base.rb:1078:in `method_missing'
from /websites/gems/blog/app/models/blog/photo.rb:6:in `<class:Photo>'
from /websites/gems/blog/app/models/blog/photo.rb:1:in `<top (required)>'
from /Users/ynkr/.rvm/gems/ruby-1.9.2-p180@rails31beta/gems/activesupport-3.1.0.rc4/lib/active_support/dependencies.rb:452:in `load'
OK, so it appears the has_attached_file method from the paperclip gem cannot be found. Why? I'm not sure.
Moving on to inherited_resources, I altered a scaffold generated controller to look like the following:
class Blog::ContextsController < InheritedResources::Base
before_filter :redirect_unless_admin
end
and load up the index page for that to which I am greeted (in the logs) with:
Started GET "/blog/contexts" for 127.0.0.1 at 2011-06-28 12:06:25 -0700
ActionController::RoutingError (uninitialized constant InheritedResources):
Rendered /Users/ynkr/.rvm/gems/ruby-1.9.2-p180@rails31beta/gems/actionpack-3.1.0.rc4/lib/action_dispatch/middleware/templates/rescues/routing_error.erb within rescues/layout (0.5ms)
My question is why are these not working? My hunch is that there is something about engines, namespacing and loading up gems that I am totally unaware of.
You need to require each gem within your engine in an initializer file, eg. lib/<your_engine_name>/engine.rb
Bit more of an explanation over here...
Rails Engine - Gems dependencies, how to load them into the application?
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