Hi,
My system has been encounter this problem, and I couldn’t find
solution after debugging. My scenario is stated below:
class user
has_many :posts
has_many :comments
end
class post
belongs_to :user
has_many :comments, :as => :commentable
end
class comment
belongs_to :post
belongs_to :user
end
For this case, I am trying to retrieve each post’s comment together
with submitter username and I write as below:
class PostsController<ApplicationController
def show
raise @post.comments.first.user.inspect
end
end
While the first time I run this script, it works fine. But, after I
hitting a refresh, it hits following problem “can’t dup NilClass”. It
is repeats the same for everytime i restart mongrel, working for the
first time and failed for the rest.
I append the application error log as below:
/opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/
base.rb:2189:in dup' /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/ base.rb:2189:inscoped_methods’
/opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/
base.rb:2193:in current_scoped_methods' /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/ base.rb:2183:inscope’
/opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/
base.rb:1548:in find_every' /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/ base.rb:1588:infind_one’
/opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/
base.rb:1574:in find_from_ids' /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/ base.rb:616:infind’
/opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/
associations/belongs_to_association.rb:44:in find_target' /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/ associations/association_proxy.rb:240:inload_target’
/opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/
associations/association_proxy.rb:112:in reload' /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/ associations.rb:1231:inuser’
Need some help for this. Thanks in advance.