In my rails application, my user is able to login once and switch between accounts as they please. When they do, I need to reinitialize their abilities since the permissions are set at the account level in the database.
My initial thought is to initialize the ability class when I detect a change in the account but not sure how to accomplish this.
I am of course open to any other idea. I am new to CanCan.
The Ability class is where all user permissions are defined.
Example:
class Ability
include CanCan::Ability
def initialize(user)
user ||= User.new # guest user (not logged in)
if user.admin?
can :manage, :all
else
can :read, :all
end
end
end
The 'can' method is used to define permissions and requires two arguments. The first one is the action you're setting the permission for, the second one is the class of object you're setting it on.
Related
I need help to configure CanCanCan using ActiveAdmin. I have everything else working including devise. I can restrict menus using devise but if you know the URL lets say for edit you can still edit that resource. I want to restrict a normal user from editing/creating any resources but it does not seem to work.
Active_Admin.rb
config.cancan_ability_class = ActiveAdmin::CanCanAdapter
Ability.rb (simple out of the box)
class Ability
include CanCan::Ability
def initialize(user)
# Define abilities for the passed in user here. For example:
#
# user ||= User.new # guest user (not logged in)
if user.admin?
can :manage, Student
else
can :read, Student
end
end
end
User model.
admin:boolean
and if I login with a user who is not an admin i can still create/edit/delete, I just want to restrict them to read only.
Please help i am struggling with this only feature that I need to complete.
Thanks in advance
Change this thinks:
config.authorization_adapter = ActiveAdmin::CanCanAdapter
config.cancan_ability_class = Ability
authorization_adapter tells active admin which adapter it should be use.
cancan_ability_class tells the adapter which class it should use.
If that still doesn't work, try to rename Ability to AdminAbility.
I am just wondering what is the proper way to use CanCan+Rolify in the simplest and most effective way.
I was under the impression that if I had an Ability model like below
user ||= User.new # guest user (not logged in)
if user.admin?
can :manage, :all
else
can :read, :all
end
And I have a resource, let`s say, Product that has
resourcify
declared, that a user that does not have the :admin role, would not be able to Create, Update or Delete such resource...
But it seems that more code is necessary to implement this behaviour, because I tested and a non :admin user IS able to delete and create a Product.
What am I missing?
Try to set load_and_authorize_resource to your Products controller (assuming that you want to make Products CRUDable only by certain roles of users).
I have Rails Admin with CanCan support in my rails app. I'm confused on one issue though. How does CanCan know what user is signed in? For example, my users can have different roles and through CanCan I assign roles for certain access into each table. When I go to localhost:3000/admin, I receive the error
CanCan::AccessDenied in RailsAdmin::MainController#dashboard
My Ability.rb file
def initialize(user)
if user and user.role.eql? :super_admin
can :manage, :all # allow superadmins to do anything
elsif user and user.role.eql? :admin
can :manage, [Location, School] # allow admins to manage only Locations and Schools
end
end
So what do I do so that user's have the ability to sign in into Rails Admin? Do I have to manually create it?
By default, CanCan will use whatever is returned by current_user. If you are using Devise within a namespace though (admin for example) then Devise actually will use current_admin_user instead. You can either create a current_user method in your ApplicationController (or some other base controller) that returns current_admin_user or overwrite the current_ability method to instantiate the Ability with current_admin_user instead.
(this is all assuming your Devise is using a namespace. By default Devise will use current_user)
You need to have a current_user method available in your controller. Assuming you have that, if you aren't signed you won't have access to a current user, so you'll need to assign a user in your ability file if it doesn't exist. In your initialize method, add user ||= User.new to make the assignment if a user doesn't already exist.
def initialize(user)
user ||= User.new
if user and user.role.eql? :super_admin
can :manage, :all # allow superadmins to do anything
elsif user and user.role.eql? :admin
can :manage, [Location, School] # allow admins to manage only Locations and Schools
end
end
I use devise for authentication and only an admin can create a user.
I use cancan to assign roles to the user during user creation.
I want the admin to view all the users roles and the admin should be able to edit the roles of the users.
How can I do this?
Check out https://github.com/marklocklear/devise_multi_tentant. In ability.rb I have...
class Ability
include CanCan::Ability
def initialize(user)
can :manage, :all if user.role == "admin"
end
end
You can add a role attributes for User model.
Then, when user go to admin dashboard, you can check user's role. If user isn't admin, redirect to another page (using before_filter :function)
But, instead doing everything manually, you can use gem cancan instead, it's so popular and easy to use!
You can find the document here: GitHub
Or in rails cast episodes 192
Basically, it'll create a ability model, and you will declare privilege for user, a sample ability class
class Ability
include CanCan::Ability
def initialize(user)
user ||= User.new # guest user (not logged in)
if user.admin?
can :update, User
end
end
end
After that, you can authorize for user in action, controller or views, like the example see this link
PS: sorry if my English was too bad, thanks:)
I was wondering how I can define an ability class and serve that ability class depending on the user that has logged in.
I am using Active Admin, Can Can and Devise and I have successfully created a User and an AdminUser models.
I have this in my ability.rb
class Ability
include CanCan::Ability
def initialize(user)
user ||= User.new
if (user)
can :manage, Item
end
end
end
Now I have used this wiki entry to determine that we can indeed define a custom ability file and use that instead of the ability.rb:
https://github.com/ryanb/cancan/wiki/changing-defaults
But what I wanted to do is, be able to use ability.rb if a "non-admin user" is signed in and a custom abilty if a user admin is signed in.
Side Question: Could it be done such that I don't need a custom one and I could set permissions in one ability.rb file?
I've never really used ActiveAdmin, so I'm not entirely sure if I'm missing something, but it doesn't seem like that framework relies on CanCan. That's why I'm assuming you're defining a current_ability method like explained in the wiki and it's instantiated with Ability.new(current_user).
If that's the case, and your current_user can be either a User or an AdminUser, then there's no problem in checking for that in the Ability class:
class Ability
include CanCan::Ability
def initialize(user)
user ||= User.new
if user.kind_of? AdminUser
can :manage, Item
elsif user.kind_of? User
can :read, Item
end
end
end
You can simply take a look at the user's type and change the rules accordingly. You can also use is_a? instead of kind_of? for stricter checking, but it's probably not required and might cause issues if you decide to do inheritance later on.
Another way you could check is by defining an admin? method in both models. This might be a better way to do it, since explicit type checking is not very popular in ruby -- it often limits your choices. It might look like this:
class User < ActiveRecord::Base
def admin?
false
end
end
class AdminUser < ActiveRecord::Base
def admin?
true
end
end
class Ability
include CanCan::Ability
def initialize(user)
user ||= User.new
if user.admin?
can :manage, Item
else
can :read, Item
end
end
end