# Use of self reflection to determine possible actions **URL:** \ **Category:** Rails\ **Created:** [December 17, 2007, 8:12pm UTC](https://www.ruby-forum.com/t/use-of-self-reflection-to-determine-possible-actions/123443 "2007-12-17T20:12:16Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![crispy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e47774/32.png) [@crispy](https://www.ruby-forum.com/u/crispy)\ **Post date:** [December 17, 2007, 8:12pm UTC](https://www.ruby-forum.com/t/use-of-self-reflection-to-determine-possible-actions/123443/1 "2007-12-17T20:12:16Z")
Is there a way to use either Ruby or Rail’s self reflection to return a list of actions a given controller can respond to? I found the “methods” method, but it appears to return everything, including all of the super class methods. I want just the actions a given controller has defined. I am trying to implement a Roles Based Access framework and want to have dynamic links based upon what a user can do. It would be nice if the controllers can tell me what is possible, and then remove those things the user isn’t allowed to do. Any suggestions? ---
**Author:** ![crispy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e47774/32.png) [@crispy](https://www.ruby-forum.com/u/crispy)\ **Post date:** [December 17, 2007, 8:15pm UTC](https://www.ruby-forum.com/t/use-of-self-reflection-to-determine-possible-actions/123443/2 "2007-12-17T20:15:48Z")
On Dec 17, 2007 1:11 PM, Crispy [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Any suggestions? > [http://destiney.com/blog/rubyonrails-get-public-actions-from-a-controller](http://destiney.com/blog/rubyonrails-get-public-actions-from-a-controller) – Greg D. [http://destiney.com/](http://destiney.com/) ---
**Author:** ![crispy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e47774/32.png) [@crispy](https://www.ruby-forum.com/u/crispy)\ **Post date:** [December 17, 2007, 8:30pm UTC](https://www.ruby-forum.com/t/use-of-self-reflection-to-determine-possible-actions/123443/3 "2007-12-17T20:30:32Z")
Crispy : > Is there a way to use either Ruby or Rail’s self reflection to return > a list of actions a given controller can respond to? ActionController::Base#action\_methods and ActionController::Base.action\_methods – Jean-François. ---
**Author:** ![crispy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e47774/32.png) [@crispy](https://www.ruby-forum.com/u/crispy)\ **Post date:** [December 28, 2007, 5:19am UTC](https://www.ruby-forum.com/t/use-of-self-reflection-to-determine-possible-actions/123443/4 "2007-12-28T05:19:03Z")
Sometimes this happen. Where you want to know actions??? On Dec 27, 2007 11:32 PM, Crispy [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > Crispy : > > > > > Is there a way to use either Ruby or Rail’s self reflection to return > > > a list of actions a given controller can respond to? > > > > ActionController::Base#action\_methods and > > ActionController::Base.action\_methods > > > > – Jean-François. – Everton J. Carpes Mobile: +55 53 9129.4593 MSN: removed\_email\_address@domain.invalid UIN: 343716195 Jabber: removed\_email\_address@domain.invalid “If art interprets our dreams, the computer executes them in the guise of programs!” - Alan J. Perlis ---
**Author:** ![crispy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e47774/32.png) [@crispy](https://www.ruby-forum.com/u/crispy)\ **Post date:** [December 28, 2007, 2:32am UTC](https://www.ruby-forum.com/t/use-of-self-reflection-to-determine-possible-actions/123443/5 "2007-12-28T02:32:58Z")
Neither of the two seem to work. I get… Evaluation failed. Reason(s): uninitialized constant ActionWebService::Dispatcher::ActionController::Base On Dec 17, 11:29 am, “Jean-François Trân” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![crispy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e47774/32.png) [@crispy](https://www.ruby-forum.com/u/crispy)\ **Post date:** [December 28, 2007, 6:10pm UTC](https://www.ruby-forum.com/t/use-of-self-reflection-to-determine-possible-actions/123443/6 "2007-12-28T18:10:59Z")
Everton, I wasn’t sure I understood your question. What I’m trying to do is implement a Role Based Access Control (RBAC) framework. Basically, a user gets assigned one or more Roles. A Role has a collection of Rights. A Right is a Controller and Action within in the applicatoin. If a user has a given right, the authenticator will allow a redirect to that Controller and Action. In the administration section of the application, where Rights are defined and assigned to Roles, I wanted to provide a drop down list of all the possible Rights to select from. Ideally, the application itself should be able to tell me what Controllers and Actions it provides via self reflection. This would have been a snap in Smalltalk, but I can’t seem to get something that works in Ruby/Rails. If one does something like allowedControllers = ApplicationController.subclasses you only get the controller that was in context (presumably because the subclasses method uses ObjectSpace), and its only a string, not the actual class. Therefore, I can’t loop through the collection and do something like allowedActions = aController.action\_methods Therefore, i’m a bit frustrated and looking for those wiser than I to clue me in. On Dec 27, 8:18 pm, “Everton J. Carpes” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![crispy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e47774/32.png) [@crispy](https://www.ruby-forum.com/u/crispy)\ **Post date:** [December 28, 2007, 8:24pm UTC](https://www.ruby-forum.com/t/use-of-self-reflection-to-determine-possible-actions/123443/7 "2007-12-28T20:24:43Z")
The problem with calling ApplicationController.subclasses is that Rails does not loadclasses until they are invoked - so all you see is the current controller. To get a list of all available controllers, you need to explicitly load them all. Example: (in your controller) def load\_all\_controllers require RAILS\_ROOT + “/app/controllers/application” # Load all the controller files controller\_files = Dir[RAILS\_ROOT + “/app/controllers/\*\*/\*\_controller.rb”] controller\_files.each do |file\_name| require file\_name end end This will pull all of the controller definitions in, giving a complete list in ApplicationController.subclasses. To use the list, you need to iterate over the entries: def iterate\_over\_controllers ApplicationController.subclasses.each do |controller\_name| controller\_name.constantize.action\_methods.each do |method| # do something with combination of controller\_name and method end end end You may also want to take a look at the User engine ( [http://agilewebdevelopment.com/plugins/user\_engine](http://agilewebdevelopment.com/plugins/user_engine) ) - even if Engines aren’t your thing, the ideas there could be useful. Note that the engine uses a rake task to sync available controller/action pairs rather than generating them on the fly. Hope this helps… –Matt On Dec 28, 2007 12:10 PM, Crispy [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > In the administration section of the application, where Rights are > the actual class. > > > > Neither of the two seem to work. > > > > > > > > Is there a way to use either Ruby or Rail’s self reflection to > > > > > Mobile: +55 53 9129.4593 – Matt J. removed\_email\_address@domain.invalid President/Technical Director, Acme Art Company ([acmeartco.org](http://acmeartco.org)) ---
**Author:** ![crispy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e47774/32.png) [@crispy](https://www.ruby-forum.com/u/crispy)\ **Post date:** [December 28, 2007, 10:02pm UTC](https://www.ruby-forum.com/t/use-of-self-reflection-to-determine-possible-actions/123443/8 "2007-12-28T22:02:11Z")
On previous post i spoke about similar question: [http://groups.google.com/group/rubyonrails-talk/browse\_thread/thread/f6c1b3a546e7e240/40233a3286dfdccf?hl=en&lnk=gst&q="Admin+and+Dry"#40233a3286dfdccf](http://groups.google.com/group/rubyonrails-talk/browse_thread/thread/f6c1b3a546e7e240/40233a3286dfdccf?hl=en&lnk=gst&q=%22Admin+and+Dry%22#40233a3286dfdccf) I have done the same thing that are you speaking about, but controllers/actions was created on a migration. I think that this should be moved to a rake task too. I think that engines like User Engine have problems for me, and so, i create RBAC system myself. On my system, i have more than just controller/action or “permissions” models, i have tools\_categories that group actions behind some “tool”. Each permission is maded by relationships between tools\_categories and roles through functions (where functions is just C-R-U-D at now). The system “introspect” function of each action based on his name (ugly, but works). When you specify a permission you just say that some role have access to create and read, but not update or delete on a specific tool. This is very simple to use and configure and works fine for me. To help me, i just add some useful methods to user model, like canCreate?(action) or canUpdate?(action) and i just overwrite link\_to\*\*\* helpers to return “” if user has no access to relative access. Note: actions like ‘‘new’’ should be classified as C (create), so links for new never will appear if the role has no permissions to create. This give more freedom to write my code, without many IFs on all views… I can give you all this code, but it’s in portuguese until now, ☹ . I will translate all and move to engine in a few days. If you want to help me, i will be grateful. On Dec 28, 2007 5:23 PM, Matt J. \< removed\_email\_address@domain.invalid\> wrote: > controller\_files = Dir[RAILS\_ROOT + > def iterate\_over\_controllers > generating them on the fly. > > > What I’m trying to do is implement a Role Based Access Control (RBAC) > > provides via self reflection. > > clue me in. > > > > > On Dec 27, 2007 11:32 PM, Crispy [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > > > > > Evaluation failed. Reason(s): > > > > > > Jabber: removed\_email\_address@domain.invalid > > > > > > “If art interprets our dreams, the computer executes them in the guise > > > of > > > programs!” - Alan J. Perlis- Hide quoted text - > > > > > > - Show quoted text - > > > [acmeartco.org](http://acmeartco.org)) > > > > > > – Everton J. Carpes Mobile: +55 53 9129.4593 MSN: removed\_email\_address@domain.invalid UIN: 343716195 Jabber: removed\_email\_address@domain.invalid “If art interprets our dreams, the computer executes them in the guise of programs!” - Alan J. Perlis ---
**Author:** ![crispy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e47774/32.png) [@crispy](https://www.ruby-forum.com/u/crispy)\ **Post date:** [December 28, 2007, 10:14pm UTC](https://www.ruby-forum.com/t/use-of-self-reflection-to-determine-possible-actions/123443/9 "2007-12-28T22:14:30Z")
One smallest p.s.: My approach was so non-intrusive, that all application was created before AC, and so i do the AC system and restrict all data under the system on a complex scope restriction, without any change on code that was made before the system. Some practices on this system could be “questionable” (abusive use of with\_scope, link\_to\*\*\* that return blank string obviously generate some invalid or ugly html (tables and lists with blank tds/items, etc)), but the clean code and very fast work done pay this price. On Dec 28, 2007 7:01 PM, Everton J. Carpes [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > create RBAC system myself. On my system, i have more than just > helpers to return “” if user has no access to relative access. > On Dec 28, 2007 5:23 PM, Matt J. \< removed\_email\_address@domain.invalid\> wrote: > > > that the engine uses > > > > > Everton, > > > all the possible Rights to select from. Ideally, the application > > > allowedActions = aController.action\_methods > > > > > > > Where you want to know actions??? > > > > > > > > > I get… > > > > > return > > > > > MSN: removed\_email\_address@domain.invalid > > > > > > > > > > > > > “If art interprets our dreams, the computer executes them in the guise of > programs!” - Alan J. Perlis – Everton J. Carpes Mobile: +55 53 9129.4593 MSN: removed\_email\_address@domain.invalid UIN: 343716195 Jabber: removed\_email\_address@domain.invalid “If art interprets our dreams, the computer executes them in the guise of programs!” - Alan J. Perlis