# Lib folders and application controllers **URL:** \ **Category:** Engines\ **Created:** [February 16, 2007, 7:47pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850 "2007-02-16T19:47:47Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 16, 2007, 7:47pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/1 "2007-02-16T19:47:47Z")
What’s the best way to handle items in your engine’s lib folder? I have a couple of support files I would normally place in my lib folder and then include in my application controller. In developing my engine, I placed these files in the lib folder within my engine. Then, I did what I would normally do and added the include code to the application controller in my engine. I quickly realized that this was being overwritten with the surrounding application’s application controller, and not wanting to require those applications to delete their application controller, I just pasted the code into the surrounding application controller (there might be a better way to do this, but one of the lines is a before\_filter). Anyway, that works when I actually run the application, but now, when I run my tests, I get an error saying: `const\_missing’: uninitialized constant ApplicationController::AuthenticatedSystem (NameError) So, I guess my question is, what is the best practice regarding both files in your engine’s lib folder as well as including code in the surrounding application’s application controller? Thanks, Trey ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 20, 2007, 11:00am UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/2 "2007-02-20T11:00:06Z")
I’m not 100% sure this is what you mean, but are you trying to include a module into ApplicationController? It sounds like you’re creating an application controller class _within_ your plugin, which is not what you want to do. If you really want to have the module included into ApplicationController automatically whenever the plugin is loaded, try adding something like this to your init.rb: ActionController::Base.send(:include, MyModule) HTH, James ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 20, 2007, 11:46pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/3 "2007-02-20T23:46:21Z")
Indeed, this is exactly what I needed for including the module. And I loaded the before\_filter with ActionController::Base.send(:before\_filter, :my\_filter) One question, where exactly in the flow does the init.rb come in? I mean, could I also do ApplicationController.send(:include, MyModule) to be a little more precise? I tried and got a some errors about uninitialized constant ApplicationController, so I’m guessing that class isn’t loaded yet. Oh well, what works works. Is there any drawbacks to adding these to the ActionController::Base instead of the ApplicationController? I realize that ApplicationController inherits from ActionController::Base (and thus it works), I am just curious. Trey ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 21, 2007, 10:51am UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/4 "2007-02-21T10:51:12Z")
At the point your plugins are loaded, it’s best to assume that nothing specific to your application is available - including ApplicationController. Consider, for example, if ApplicationController had references (includes, method invokations) which were provided by plugins that are loaded _after_ this one? It’s definitely going to crash and burn. Another historical reason is that in development mode ApplicationController was unloaded and then reloaded for each request. This would mean that any additions you’d made to the class would be lost after the first time you hit your development server. ActionController::Base is a part of the framework, and so isn’t reloaded since it’s never expected to change. HTH James ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 21, 2007, 11:51pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/5 "2007-02-21T23:51:03Z")
The approach I’ve used is to place the relevant code in the my\_engine.rb module under lib, then include MyEngine in application.rb That approach has worked fairly well for me. - Tony ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 21, 2007, 11:44pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/6 "2007-02-21T23:44:01Z")
That makes sense. It just feels a little weird sending something to ActionController::Base (I’d rather programatically add these lines to the surrounding app’s application controller), but I think I can get over it. One further question though: I mentioned in my last email, that I did the same thing with a before\_filter and put the following in my init.rb ActionController::Base.send(:before\_filter, :my\_filter) This works when I run the site with script/server, but if I run my tests with rake test:plugins PLUGIN=my\_plugin, it doesn’t invoke the before\_filter. I’ve placed a puts line at the top of the my\_filter method, so I can see when it’s called, and through scirpt/server it is called with every request, as expected, but through the tests, it never gets called. The odd thing is that I’ve verified that init.rb is getting called and that my other line in init.rb, ActionController::Base.send(:include, MyModule) is being loaded. Should I not be doing this with before filters? Or should I be doing something else in the test to make sure the before\_filter is set up correctly. Trey ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 3:01pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/7 "2007-02-27T15:01:55Z")
We’re experiencing some problems which look like the earlier mentioned ones. Somehow the relations within our models are gone after one request. This isn’t the case when we are in production mode, so it has something to do with loading. In the init.rb we are extending the ActionController::Base by using “ActionController::Base.class\_eval do” if we use send on calls to ActiveRecord like permission.send(:find, :all) it only works on the first call. As soon as we reload the page, it breaks. Again in production mode it just works. We will be wading through the rails core and post back if we find something. Help is greatly appreciated. Kind regards, Jeroen van Doorn ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 3:37pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/8 "2007-02-27T15:37:00Z")
I have a similar problem with certain calls in my init.rb only being picked up on the first request… It appears to me like init.rb is only getting run once during start-up. This would explain why the mixins disappear after the first request - when the entire environment gets reloaded, anything that was added in init.rb will not get added the second time! Having said that, other plugins are still being loaded and mixed in correctly on subsequent requests… I have a feeling it’s to do with the way engines enhanced plugins are loaded but I’m not entirely sure how… Tekin ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 4:00pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/9 "2007-02-27T16:00:05Z")
We have a workarround, but we think it’s quite dirty! you could just add an empty model file to your apps model dir and just require the original model. In a test engine we don’t have an init.rb and the relations work properly over there. Keep you posted. Jeroen Tekin S. schreef: ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 4:22pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/10 "2007-02-27T16:22:09Z")
Do you think this may be related to the recent changes to the way dependencies are reloaded? > **[Reloading Revamped](https://rubyonrails.org/2006/8/11/reloading-revamped)** > > A few days ago I checked in a significant improvement to Rails’ dependencies and reloading code. In the past, changes to dependencies.rb have shed the blood of those courageous enough to ride edge; We’ve worked hard to prevent accidental breakage... Also, I came across: Dependencies.log\_activity = true In my case, I am directly accessing, and modifying another plugin’s model in an init.rb. > From a quick scan of the dependency log, it looks like my model is > getting reloaded during each request, which is happening after > initialisation and thus overriding anything in the init.rb It looks like engines reloads all plugins after initialisation to add the engines enhancements, which would explain why modifications are picked up for the first request, as it happens after the app has been loaded. I guess the neat fix would be to get engines to reload after each request and not just in after\_initialize() ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 4:46pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/11 "2007-02-27T16:46:14Z")
We’re really lost. I don’t have clue where to look. We’re still going through rails and engines code, but we just don’t get it at this moment. We’re not modifying other models b.t.w., but if we don’t use a init.rb at all it just works. A solution would be to put all the code in a lib and include it in the appcontroller, but I don’t think this is a elegant solution. Anyway I really want to understand why things are going wrong. I’m going home, have a good night’s sleep and have a look at it again tomorrow. @James A., do you have any clue on what we’re doing wrong ? Kind regards, Jeroen van Doorn Tekin S. schreef: ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 4:46pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/12 "2007-02-27T16:46:14Z")
On 2/27/07, Tekin S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > It appears to me like init.rb is only getting run once during start-up. This is definitely the case, and is typically why you don’t mix modules from plugins into _anything_ that will get reloaded. For example, if you’re adding methods to all controllers, you should include your module into ActionController::Base, not ApplicationController. The same applies for the rest of your application… ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 4:27pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/13 "2007-02-27T16:27:12Z")
> > I guess the neat fix would be to get engines to reload after each > > request and not just in after\_initialize() Or to not modify another plugin’s model in an init.rb!! ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 5:22pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/14 "2007-02-27T17:22:22Z")
Of course. I need to rethink my architecture, specifically how my plugins integrate together. On the most simple level, I have a cms plugin that provides a generic cms, and other plugins will add additional functionality to it (catalogue/ecommerce, etc). I basically need to tell my Page model in the cms plugin that it has additional behaviours. At the moment, I simply have a class attribute array called @behaviours which the other plugins are adding to in their init.rb’s. Obviously this is unworkable. Is there an obvious way to modify models in other plugins in such a way that it get’s picked up on reloads? My current thinking is that maybe the Page model should check for and load any enhancements into itself, looking in each plugin… ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 5:41pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/15 "2007-02-27T17:41:29Z")
Really? You can’t mix a module from a plugin into your app - you have to add it into Rails?? That just seems somehow wrong to me. I thought I could mix a module in anywhere I want - if the main class gets reloaded, why won’t it’s dependencies get reloaded as well? Is that in general, or only with engine plugins? In any case, I’m running into the same problem with ActiveRbac. First run, everything works. Second run, methods for a model just disappear. In order to create a model that doesn’t have to be completely copied into the application to be overridden, they created a model file that simply includes a mixin module with all the real code. So to override the model in my app I create the model file, include the mixin files, and my new functions. The problem seems to be in one of the models that I don’t override. First run everything is fine, second run _non_ of it’s methods are found. It’s not just the mixed in ones. I added a method straight in to the model - it wasn’t available on the second run. Here is an interesting error I get if I try to do a find on the model: ArgumentError: A copy of ActiveRbacMixins::UserMixins::Core has been removed from the module tree but is still active! This worked fine in the previous Rails and Engines. So this is new behavior. What’s the best way to fix it? ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 5:54pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/16 "2007-02-27T17:54:32Z")
I think my description may have not been very clear, there is infact very little magic going on at all! Each page has a behaviour attribute. For most pages, this is simply left blank. If however, it is set to something, like for example, ‘contact’ or ‘news’, when the page is rendered, extra ‘stuff’ is added to the rendered page using partials. This all works fine, all I want is for the page model to have a list of potential behaviours - nothing more than an array of strings - which is what I need to add to from future plugins… Does that make sense? I guess I could put this in the application somewhere, it just makes sense for it to happen in the plugins. Thanks for all the great work on engines by the way, it’s made it much easier for us to share rails code between our projects, the way it should be. ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 6:08pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/17 "2007-02-27T18:08:38Z")
Why create the model file at all in your app? Couldn’t you simply open the module and override/add your functions? ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 5:32pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/18 "2007-02-27T17:32:25Z")
On 2/27/07, Tekin S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Obviously this is unworkable. Is there an obvious way to modify models > in other plugins in such a way that it get’s picked up on reloads? This is one of the occasions where you might actually want to adopt “less magic”. Is there any way you could architect it so each plugin contributes a feature to a Page model within the application? I.E. class Page \< AR::Base with\_cms\_features # from the cms plugin and\_versioning # from your versioning plugin, for instance format\_with\_markdown # from your text processing plugin ``` # ... ``` end The lesson learned from the login+user engine saga is: don’t try to have plugins depend on other plugins. It gets way too complicated. Is there any way you can avoid this? I appreciate that this might really be the advice you need at the moment; if I think of anything tonight I’ll fire of another mail to the list. ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 6:09pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/19 "2007-02-27T18:09:38Z")
On 2/27/07, Brett W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Really? You can’t mix a module from a plugin into your app - you > have to add it into Rails?? That just seems somehow wrong to me. I > thought I could mix a module in anywhere I want - if the main class > gets reloaded, why won’t it’s dependencies get reloaded as well? Is > that in general, or only with engine plugins? You’re talking about a few things here. Imaging the situation: app/models/a.rb: class A end app/models/b.rb class B include C end vendor/plugins/monkey/lib/c.rb module C end vendor/plugins/monkey/init.rb: A.send(:include, C) When your application first loads, init.rb is evaluated, and C is included into A. C is also included into B, as per normal. At the end of the request, A and B are dutifully unloaded to make way for any changed versions. The next request causes Rails to try to find A again, which it does in app/models/a.rb, and so it loads that file. However, because vendor/plugins/monkey/init.rb is only ever evaluated at the start of the request cycle, the “new” A will NOT include the module C. Since B explicitly refers to C, when Rails tries to reload B from app/models/b.rb, it re-reads the class definition and includes C as you’d expect. The point here is that the only place where it states that A should include C is a file that is only ever evaluated once, and that information is lost when the target class is unloaded. This is what plugin developers typically send includes to ActionController::Base, not ApplicationController. > In any case, I’m running into the same problem with ActiveRbac. > First run, everything works. Second run, methods for a model just > disappear. In order to create a model that doesn’t have to be > completely copied into the application to be overridden, they created > a model file that simply includes a mixin module with all the real > code. So to override the model in my app I create the model file, > include the mixin files, and my new functions. That’s basically what’s going on with class B, above. > The problem seems to be in one of the models that I don’t override. > First run everything is fine, second run _non_ of it’s methods are > found. It’s not just the mixed in ones. Just to be sure that I know what you’re referring to: - there is a model within a plugin - it has, say, method “do\_something” defined directly in the class - on the second request, the model class is still available but the method has disappeared Is that right? > I added a method straight > in to the model - it wasn’t available on the second run. Here is an > interesting error I get if I try to do a find on the model: > > ArgumentError: A copy of ActiveRbacMixins::UserMixins::Core has been > removed from the module tree but is still active! I can’t speak for ActiveRbac specifically, but I’ve never, ever encountered this error. Very weird. > This worked fine in the previous Rails and Engines. So this is new > behavior. What’s the best way to fix it? Since any version of ActiveRbac that was compatible with the engines plugin 1.1.x releases isn’t compatible with the 1.2 release, you should also note that ActiveRbac must’ve changed. If you can reproduce this in a clean project using the engines plugin and a toy plugin to contain the model, please zip it up and email it directly to me. I’m very keen to resolve this, but I need to be able to reproduce the behaviour… Cheers ---
**Author:** ![treybean](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/47e85d/32.png) [@treybean](https://www.ruby-forum.com/u/treybean)\ **Post date:** [February 27, 2007, 6:10pm UTC](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850/20 "2007-02-27T18:10:40Z")
Sorry, what I meant was; maybe having the second model file in your app is what’s causing the problem? [http://api.rails-engines.org/classes/Engines/RailsExtensions/Dependencie](http://api.rails-engines.org/classes/Engines/RailsExtensions/Dependencie) s.html > > Why create the model file at all in your app? Couldn’t you simply > > open the module and override/add your functions? [Next page](https://www.ruby-forum.com/t/lib-folders-and-application-controllers/85850.md?page=2)