NoMethodError after upgrading from 1.1.6 to 1.2.3

Rails
1

After upgrading from Rails 1.1.6 to 1.2.3 I receive a NoMethodError
when loading a particular page in my app (see
Parked at Loopia).
Here’s what I know about it:

-The issue occurs in the development environment, but not in the
production environment on the same CPU using the same database under
the same server software/rails installation
-If the troublesome page is loaded directly it loads the first time
and throws the error on subsequent loads
-If the troublesome page is loaded through a link from another page it
throws an error immediately
-The “q” variable does not change between lines 6 and 7
-The page executes to line 6 without error
-No changes have been made to the models, controller or view involved
since upgrading
-The page operated normally in development and production environments
under 1.1.6

What could be causing this problem?

http://pastie.caboo.se/125097

2

On Dec 5, 8:06 pm, Evan [email protected] wrote:

After upgrading from Rails 1.1.6 to 1.2.3 I receive a NoMethodError
when loading a particular page in my app (seehttp://pastie.caboo.se/125097).
Here’s what I know about it:

This sounds like a dependency problem (there were a bunch of changes
to that for rails 1.2). In a nutshell, between requests rails clears
out all your controllers, models etc… and loads fresh ones. If that
goes wrong, then you can end up with something using the old Question
class (the one that rails cleared out) and shit happens. Classes
aren’t reloaded between requests in production, so the problem doesn’t
exist there.

Reasons i’ve seen this happen

  • plugins: by default these are not reloading between requests, so if
    a plugin holds onto a class it will get borked
  • requiring things ‘by hand’. This bypasses the rails autoload magic
    and so it gets confused. Use require_dependency, or let autoloading do
    its magic
  • doing weird stuff like including a module into the top level
    I can’t see any of this in the code you’ve shown, but it doesn’t
    necessarily have to be (eg stuff in your environment.rb could do it,
    stuff in the editor model could do it etc…
    Hopefully this should point you in the right direction. The
    Dependencies stuff can log all the stuff it does, which can be helpful
    in tracking down this sort of stuff.

Fred

3

Fred,

That does give me some more direction. Thank you. How do I activate
the dependencies logging?

Evan

4

On 5 Dec 2007, at 20:30, Evan wrote:

Fred,

That does give me some more direction. Thank you. How do I activate
the dependencies logging?

You set Dependencies.log_activity to true. In addition there are
plenty of good methods in there to pepper with extra logging. Also
checkout ActiveRecord::Base.reset_subclasses if there is a class there
that isn’t being unloaded then logging there can pick that up

Fred

5

On 5 Dec 2007, at 21:02, Rob B. wrote:

-If the troublesome page is loaded directly it loads the first time
under 1.1.6

Arguably bad form, but hardly accounts for it working in production
and working in development mode the first time.
You can get away with it because ‘advice’.singularize == ‘advice’

Fred

6

On Dec 5, 2007, at 3:06 PM, Evan wrote:

-If the troublesome page is loaded through a link from another page it
Parked at Loopia
shouldn’t it be

has_many :advices
(i.e., plural like the table name, not singular)

-Rob

Rob B. http://agileconsultingllc.com
[email protected]

7

I wouldn’t recommend using a word that cannot be pluralised. Try its
synonyms:

On Dec 6, 2007 8:22 AM, Frederick C. [email protected]
wrote:

Here’s what I know about it:
-The page executes to line 6 without error

–
Ryan B.

8

I agree with Rob. Seems like the problem is in the naming. I would
try it with the model name ‘advices’, or a more straight-forward word
like ‘answers’ or ‘suggestions’. Then, you can change the view code
to read “<% if q.advices.empty? %>”

good luck

9

Evan wrote:

After upgrading from Rails 1.1.6 to 1.2.3 I receive a NoMethodError
when loading a particular page in my app (see
Parked at Loopia).
Here’s what I know about it:

-The issue occurs in the development environment, but not in the
production environment on the same CPU using the same database under
the same server software/rails installation
-If the troublesome page is loaded directly it loads the first time
and throws the error on subsequent loads
-If the troublesome page is loaded through a link from another page it
throws an error immediately
-The “q” variable does not change between lines 6 and 7
-The page executes to line 6 without error
-No changes have been made to the models, controller or view involved
since upgrading
-The page operated normally in development and production environments
under 1.1.6

What could be causing this problem?

Parked at Loopia

Try adding the following statement in question.rb

require ‘advice.rb’

10

I have adjusted the plurality of the advice/question association in
the models, controllers and views and the issue persists.

11

I have tried adding “require ‘advice.rb’” to the Question class
definition and the issue persists.

12

On 7 Dec 2007, at 05:40, Evan wrote:

I have tried adding “require ‘advice.rb’” to the Question class
definition and the issue persists.

Are you sticking an entire editor object in the session? Does changing
that fix things?

Fred

13

Hmmm…I activated dependencies logging, but am not sure what to make
of the logged activity.

http://pastie.caboo.se/125830

On Dec 5, 12:34 pm, Frederick C. [email protected]

14

On 7 Dec 2007, at 05:37, Evan wrote:

Hmmm…I activated dependencies logging, but am not sure what to make
of the logged activity.

Parked at Loopia

Well you can sort of see what is happening, if you compare the good
load with the bad load:

Good:

Processing EditingController#index (for 127.0.0.1 at 2007-12-06
21:11:01)
[GET] Session ID: bd965b771927a6b290bbdc5018fe0364
Parameters: {“action”=>“index”, “controller”=>“editing”}
DEPRECATION WARNING: @session is deprecated! Call session.[] instead
of @session.[]. Args: [“editor”] See

for details. (called from editor? at /Users/evan/Rails/asktheguys/
asktheguys/public/…/config/…/lib/editor_system.rb:87)
DEPRECATION WARNING: @session is deprecated! Call session.[] instead
of @session.[]. Args: [“editor”] See

for details. (called from login_required at /Users/evan/Rails/
asktheguys/asktheguys/public/…/config/…/lib/editor_system.rb:47)
Dependencies: called load_missing_constant(Object, :Question)
Dependencies: called require_or_load(“/Users/evan/Rails/asktheguys/
asktheguys/public/…/config/…/app/models/question.rb”, nil)
Dependencies: loading /Users/evan/Rails/asktheguys/asktheguys/
public/…/config/…/app/models/question Dependencies: called
load_file(“/Users/evan/Rails/asktheguys/asktheguys/public/…/config/…/
app/models/question.rb”, [“Models::Question”, “Question”])
Dependencies: called new_constants_in(“Models”, :Object)
Dependencies: New constants: Question Dependencies: loading /Users/
evan/Rails/asktheguys/asktheguys/public/…/config/…/app/models/
question.rb defined Question
Question [4;36;1mQuestion Columns (0.000593) [0m [0;1mSHOW FIELDS
FROM questions [0m [4;35;1mSQL (0.000748) [0m [0mSELECT count(*) AS
count_all FROM questions [0m [4;36;1mQuestion Load (0.000936) [0m
[0;1mSELECT * FROM questions ORDER BY questions.created_on DESC LIMIT
0, 10 [0m

Bad:

Processing EditingController#index (for 127.0.0.1 at 2007-12-06
21:11:09)
[GET] Session ID: bd965b771927a6b290bbdc5018fe0364 Parameters:
{“action”=>“index”, “controller”=>“editing”}
DEPRECATION WARNING: @session is deprecated! Call session.[] instead
of @session.[]. Args: [“editor”] See

for details. (called from editor? at /Users/evan/Rails/asktheguys/
asktheguys/public/…/config/…/lib/editor_system.rb:87)
DEPRECATION WARNING: @session is deprecated! Call session.[] instead
of @session.[]. Args: [“editor”] See

for details. (called from login_required at /Users/evan/Rails/
asktheguys/asktheguys/public/…/config/…/lib/editor_system.rb:47)
[4;36;1mQuestion Columns (0.001567) [0m [0;1mSHOW FIELDS FROM
questions [0m [4;35;1mSQL (0.000583) [0m [0mSELECT count(*) AS
count_all FROM questions [0m [4;36;1mQuestion Load (0.000810) [0m
[0;1mSELECT * FROM questions ORDER BY questions.created_on DESC LIMIT
0, 10 [0m
See how in the first case Question is loaded from question.rb, but not
in the second case → something is hanging on to a stale reference to
the question class, and it’s something that happens in
editor_system.rb (like i said in my other mail, if you’re putting an
editor object in the session, that’s bad)

Fred