# Calling methods from the "main" application **URL:** \ **Category:** Engines\ **Created:** [March 22, 2006, 4:56pm UTC](https://www.ruby-forum.com/t/calling-methods-from-the-main-application/85356 "2006-03-22T16:56:55Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![chriscole](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/5fc32e/32.png) [@chriscole](https://www.ruby-forum.com/u/chriscole)\ **Post date:** [March 22, 2006, 4:56pm UTC](https://www.ruby-forum.com/t/calling-methods-from-the-main-application/85356/1 "2006-03-22T16:56:55Z")
I’ve successfully setup a publication engine (Publish) which I use to learn ROR but there is something I can’t find a solution for : the main application (the one which make uses of this engine) has a “admin” layout which need to get a menu for EVERY engine installed… Let’s call it getMenu() 1. I don’t know where to define getMenu() - I’ve tried in several places - init\_engine.rb included but got several error messages (ranging from “method not found” to “trying to access private method”) 1. How can I iterate throught all the engines installed and check if the getMenu method exists ? Point 1 is the most important for me as I don’t understand how I can make methods and attributes accessible to the outside world. For now, every piece of code executed by my engine is the result of a controller/action sequence. Same goes for engine to engine calls… How can I do ? Thanks ---
**Author:** ![chriscole](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/5fc32e/32.png) [@chriscole](https://www.ruby-forum.com/u/chriscole)\ **Post date:** [March 22, 2006, 5:08pm UTC](https://www.ruby-forum.com/t/calling-methods-from-the-main-application/85356/2 "2006-03-22T17:08:25Z")
Hi, Firstly, to get an array of all the running engines, you can use simply Engines.active - that part is easy. Read the Engines RDoc for more details. You should define your getMenu() method as part of some module, and use a consistent convention for the naming of those modules. For instance, if you have three engines (‘alpha\_engine’, ‘beta\_engine’, ‘gamma\_engine’), then you will probably be defining modules for each of those engines, so you could have: /vendor/plugins/alpha\_engine/lib/alpha\_engine.rb: module AlphaEngine def AlphaEngine.getMenu() #… end end … and so on for BetaEngine and GammaEngine. That said, where you place the method really depends what your getMenu method does. You might instead want to put it in an appropriately named module within the app/helpers directory of each engine. The key to detecting the availablity of this method is going to be following a well-defined convention for it’s placement. - james On 3/22/06, Christophe C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > ## getMenu method exists ? > > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). > > * * * > > engine-users mailing list > removed\_email\_address@domain.invalid > [http://lists.rails-engines.org/listinfo.cgi/engine-users-rails-engines.org](http://lists.rails-engines.org/listinfo.cgi/engine-users-rails-engines.org) – - J \* ~ ---
**Author:** ![chriscole](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/5fc32e/32.png) [@chriscole](https://www.ruby-forum.com/u/chriscole)\ **Post date:** [March 22, 2006, 6:35pm UTC](https://www.ruby-forum.com/t/calling-methods-from-the-main-application/85356/3 "2006-03-22T18:35:18Z")
Thank you for your help James, using your solution I solved my problem in a minute… Now, you said that I could use the same solution and put getMenu() in a helper… It would be better because the script in the lib directory is only reloaded when webrick starts - So, I’ve tried with something in a helper (helper directory under my engine): module PublishHelper def PublishHelper.getmenu() # snip end end But that doesn’t work - In the app’s layout , using PublishHelper::getmenu produces an error “uninitialized constant ArticleHelper” Is there something special to do to use helpers or each script in the engine’s helper directory is automatically provided to the main application ? ---
**Author:** ![chriscole](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/5fc32e/32.png) [@chriscole](https://www.ruby-forum.com/u/chriscole)\ **Post date:** [March 22, 2006, 6:40pm UTC](https://www.ruby-forum.com/t/calling-methods-from-the-main-application/85356/4 "2006-03-22T18:40:26Z")
Helpers are automatically loaded by controllers if they share the same root name, i.e. the ‘PublishController’ will try and load the ‘PublishHelper’… if you want to include other helpers, you need to explicitly include them in your controller, probably using the ‘helper’ class method, i.e. class PublishHelper \< ApplicationController helper :article # … end BTW, to call a ‘class-level’ method, you should be using PublishHelper.getmenu(), rather than PublishHelper::getmenu() - james On 3/22/06, Christophe C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > def PublishHelper.getmenu() > engine’s helper directory is automatically provided to the main > application ? > > – > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). > > * * * > > engine-users mailing list > removed\_email\_address@domain.invalid > [http://lists.rails-engines.org/listinfo.cgi/engine-users-rails-engines.org](http://lists.rails-engines.org/listinfo.cgi/engine-users-rails-engines.org) – - J \* ~ ---
**Author:** ![chriscole](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/5fc32e/32.png) [@chriscole](https://www.ruby-forum.com/u/chriscole)\ **Post date:** [March 23, 2006, 11:11am UTC](https://www.ruby-forum.com/t/calling-methods-from-the-main-application/85356/5 "2006-03-23T11:11:29Z")
Thanks again James - This timeit works also with an helper ! But I wonder why the helpers are not reloaded dynamically ? I’m working in development mode and I need to restart WebRicks to see the results of the changes made in the helper source code…