Use of self reflection to determine possible actions

Rails
1

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?

2

On Dec 17, 2007 1:11 PM, Crispy [email protected] wrote:

Any suggestions?
http://destiney.com/blog/rubyonrails-get-public-actions-from-a-controller

–
Greg D.
http://destiney.com/

3

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.

4

Sometimes this happen.

Where you want to know actions???

On Dec 27, 2007 11:32 PM, Crispy [email protected] 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

РJean-Fran̤ois.

–
Everton J. Carpes
Mobile: +55 53 9129.4593
MSN: [email protected]
UIN: 343716195
Jabber: [email protected]

“If art interprets our dreams, the computer executes them in the guise
of
programs!” - Alan J. Perlis

5

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” [email protected]

6

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” [email protected]

7

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 ) - 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 [email protected] 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.
[email protected]
President/Technical Director, Acme Art Company (acmeartco.org)

8

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

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, :frowning: . 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. < [email protected]> 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 [email protected] wrote:

Evaluation failed. Reason(s):

Jabber: [email protected]

“If art interprets our dreams, the computer executes them in the guise
of
programs!” - Alan J. Perlis- Hide quoted text -

–
Everton J. Carpes
Mobile: +55 53 9129.4593
MSN: [email protected]
UIN: 343716195
Jabber: [email protected]

“If art interprets our dreams, the computer executes them in the guise
of
programs!” - Alan J. Perlis

9

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 [email protected]
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. < [email protected]> 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: [email protected]

“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: [email protected]
UIN: 343716195
Jabber: [email protected]

“If art interprets our dreams, the computer executes them in the guise
of
programs!” - Alan J. Perlis