CanCan Ability Model - ruby-on-rails

I have a Rails 4 app that i wrote a CanCan Ability model for based on my model setup in my app. While testing it works sometimes and then it doesn't. Im not sure what the problem is. There is nothing in the logs that would point to a problem. I also don't think that it is that clean anyway. Any suggestions on how to improve this Ability model? It seems very redundant and confusing.
if user
##
can :manage, User do |u|
case u.account
## If user is a Developer allow it to only be managed by itself (user)
when Developer
u == user
## If user is a Organization allow it to only be managed by it's founders
when Organization
u.account.founders.exists?(user)
else
false
end
end
can :manage, App do |a|
case a.appable
## If app belongs to a Developer allow it to only be managed by it owner (developer)
when Developer
a.appable.id == user.id
## If app belongs to a Organization allow it to only be managed by its organizations' founders
when Organization
a.appable.founders.exists?(user)
else
false
end
end
##
end

As for cleaning it up, you could consider instead organizing the logic by user role. This way you can easily look at a given role and understand all the abilities that they do and do not have access to.
Something like this:
if user.developer?
can :manage User, id: user.id
can :manage App, App.appable_by(user)
end
NOTE: you may need to write some custom finders like App.appable_by(user) in order to test the rule
I don't fully follow what you are trying to do with Organization / founders. If this is a role like user.founder? Then treat it like mentioned above, but with a different authorization rule.

Related

Who handle the roles of a User in Rails?

I'm making a Rails 6 application where I'm using Devise for authentication, Pundit for authorization and I added Active-Admin because I need a dashboard where admin users manage the content of the app.
Other than admin, I have a couple of more roles president, manager, guest. An admin can be president or manager.
I'm little confuse on what to use to implement the roles, with devise? pundit? I do it by hand?
Is it better to unite the User and the AdminUser model active-admin created? Because this way UserAdmin users can't log in to the application, only to the dashboard and that is not what I want.
I have seen tutorials where people add an admin:boolean column to the users, should I do something like that?
Is it better to unite the User and the AdminUser model active-admin created? Because this way UserAdmin users can't log in to the application, only to the dashboard and that is not what I want.
That depends more on your business logic. It may be a good idea to keep your users and admin_users tables separated; The users table will probably need to have a lot of associations with other tables, that will not be necessarily needed by admin_users, right?
I'm little confuse on what to use to implement the roles, with devise? pundit? I do it by hand?
You may define a role column in your admin_users table, and use that column in pundit policies, for example:
class ResourcePolicy
# ...
# ...
# ...
def update?
user.admin? || user.president?
end
end
in AdminUser, you can do the following:
class AdminUser < ActiveRecord::Base
def admin?
role == 'admin'
end
def president?
role == 'president'
end
end
There are many other ways to implement that, and they all depend on what you need to achieve.

How should I structure two types of Roles in a Rails application?

I am working on a Ruby on Rails application that has two kinds of "Roles".
One will be where a user has multiple roles, such as "Admin", "Team Lead", etc. these will be defined in the seeds file and not generated by the user.
The other will be generated by a User and assigned to other users, such as "Chef", "Waiter", etc.
They are both similar in that they only have a name column. The former will be used with an authorization tool such as CanCanCan. I currently plan to allow users and roles to have many of the other using a has_many :through relationship.
class Role
has_many :user_roles
has_many :users, through: :user_roles
end
class User
has_many :user_roles
has_many :roles, through: :user_roles
end
class UserRole
belongs_to :user
belongs_to :role
end
My questions are:
Should the latter ("Chef", "Waiter", etc) be put in the same table? Separate tables?
Should I use some kind of inheritance?
What's a good practice for this situation?
I plan to use the term "Role" in the user interface for the latter, showing what "Roles" a user has. The former I guess is more about what privileges they have within the application.
If you go away from the technical side of roles and authentication, and try to describe the "things" from a more business oriented approach you make the distinction clearer for yourself.
What I understand is: You have a definition for a user of your application that is used to describe what authorization this user has, e.g. an "admin" has more rights than an "editor" or "community manager".
You also want these users of your application to be able to create names that are associated with (other?) users. Theses names have nothing to do with authorization, as I understood.
Maybe these names are more like tags, that people can assign?
I would keep both separated, as it shouldn't be able for a user to create a role, or modify existing roles, that could grant them access to admin features.
If you want to look at a tagging gem, I could recommend this one: https://github.com/mbleigh/acts-as-taggable-on I used this for several years and while it has its drawbacks, it's reliable.
I'd suggest having a look at rolify before rolling your own solution, as it will have solved some things that you'll have to reimplement / discover later (e.g. role queries, avoiding N+1 queries etc). It also integrates well with can?, and should work well for the authorisation part of your question.
Whilst it's not impossible to allow users to create new roles (by throwing an input form on top of Role.create), this starts to get messy, as you need to track which ones are for authorisation and which ones informative (and user created).
Since the two groups of things are for different purposes, I wholeheartedly agree with this other answer that it's cleaner to separate the user-generated entities, and look to implement them as tags. You may display all the "roles" together in certain views, but that doesn't mean that it makes sense to store them within a single table.
Side-note: if you do end up rolling your own solution, consider using HABTM here. The join table will still be created, but you won't have to manage the join table model. E.g.
has_and_belongs_to_many :users, join_table: :users_roles
Since you only have a limited number of roles, you could use a bitmask and store directly on the user model as a simple integer.
See this Railscasts for more information. That would be the most efficient, database and association wise, way to do this although perhaps not the simplest to understand. The only real restriction is that you can't alter the array of values you check against, only append to it.
Good luck!
I would create one more model, Permission, where you can create a list of all the permissions you want to manage under any given role.
Then have a many to many between Permissions and Roles.
From a UserRole instance then you will be able to list the permissions, and in the future you could add additional permissions to roles buy just running inserts in a couple of tables
Roles: Onwer, Chef, Cook, Waiter
Permission: can_cook, can_buy_wine, can_manage, can_charge_custome
Owner: can_manage, can_buy_wine, can_charge_customer
Chef: can_cook, can_manage
Waiter: can_charge_customer
Is would be a good start and you can evolve the role functionality to whatever your needs are without an external dependency.
Also, You can go just using Users table and adding role column as integer and give them a role code in default 0 integer.
#app/helpers/roles_helper.rb
module RolesHelper
#roles = {
'Default' => 0,
'Waiter' => 10,
'Chef' => 20,
'Superadmin' => 30
}
class << self
def list_roles
#roles.map{|k,v| [k,v] }
end
def code(str)
return #roles[str]
end
def value(id)
return #roles.key(id)
end
end
def require_default_users
unless current_user && current_user.role >= RolesHelper.code('Waiter')
redirect_to root_url(host: request.domain)
end
end
def require_superadmin_users
unless current_user && current_user.role >= RolesHelper.code('Superadmin')
redirect_to courses_path
end
end
end
access in controllers
sample:
class Admin::AdminController < ApplicationController
include RolesHelper
def sample_action_method
require_default_users #if non admin user redirect ...
puts "All Roles: #{RolesHelper.list_roles}"
puts "Value: #{RolesHelper.value(30)}"
puts "Code: #{RolesHelper.code('Superuser')}"
end
end

How can I restrict User role assignment using CanCan?

Using a combination of a few tutorials and screencasts to set up Rails and CanCan to work with Devise etc. I've established User, Role, and the UserRole joining model for the has_many :through connection. And I only want some users to be able to assign certain roles, or create new accounts with those roles, etc.
Based on the documentation here, I feel like this should be pretty straightforward. What I have is essentially this:
if user
if user.role? 'admin'
can :manage, User
elsif user.role? 'submanager'
can :manage, User, roles: { name: ['basic', 'premium'] }
end
else
can :create, User, roles: { name: ['basic'] }
end
And then I'd simply test it in the form with:
- if can? :create, User, roles: { name: 'admin' }
= check_box 'user[role_ids]', 'admin'
Or, at least, that's the gist. And trust me I've tried every combination of singulars, plurals, role_ids, role, role: [ ]. So I don't think it's something as simple as that. No matter what I do, the can? check passes. Every time. Without fail.
I've found a lot of stuff out there on CanCan but I can't seem to find this specific thing. Is it because I'm trying to misuse CanCan, and I should be doing this some other way? Or … how do I do this?
I don't think this should be done in CanCan, as the control granularity of CanCan is on action. So if you really wanna to use CanCan to fulfill your intention, I think you should make the ”role change“ as a method call instead of a form submission.
the controller file
class UserController
def basic
user.change_role_to_basic
end
def premium
user.change_role_to_premium
end
end
the ability file
can :basic, User do
end
can :premium, User do
end

Set Up Admin Users to Edit Users, Articles, Collaborators

I am trying to solve an issue I'm having with setting up admin on my site. Here is a simple version of my routes.
resources :users
resources :articles
resources :collaborators
end
resources :admin
Admin users are very similar to Collaborators, because they can edit and create Articles, but Admin has the ability to also c.r.u.d. Users, Collaborators, and Articles for every User. Collaborators can only c.r.u.d. Articles that are associated with the User they have been assigned to.
The part where this gets a little bit confusing is how to set up the controller and views that Admin uses for CRUD operations. As of now the way I am trying to implement it is to create separate CRUD views within admin/. The problem with this is that the functionality is so simimlar to a collaborator, I feel like it could be DRYer somehow.
Anybody know the most basic way to implement something like this? Thanks!
Update: I'd like to update this to say that it's super easy to google admin tools for rails. I'm more wondering how to implement this without an admin tool, or if that sounds like a bad idea, why?
The answer I came up with is to create Collaborators with an admin field true / false. I also set up CanCan and it's working pretty nicely.
Here is my CanCan ability.rb
def initialize(user)
if user.admin?
can :manage, :all
else
can :manage, Article, :id => user.article_id
cannot :index, Article
end
end
I just used "user" because it's more readable and shorter than collaborator and basically a user...
Try ActiveAdmin (http://activeadmin.info/). I think it is the most simplest way to build administrator backend for your application.

Whats the best approach for using sorcery(auth) with multiple user classes?

I`m looking to create two models: trainer & client.
When signing up those two types of models share the basic auth info, such as email & password.
Thus I would like to use Sorcery to do the authentication for me, the gem creates a User model by default.
Searching through StackOverflow I understand I could use Single Table Inheritance, which most people find problematic.
Is there a better/simpler solution for those two types of users to share the basic auth info but be separate models which would contain their role specific data?
I`m sorry if I mixed things up.
What kind of "role specific data" do your two users have?
I was in a very similar situation as you are in an app that I'm still developing. I chose to use a role based approach using CanCan.
class User < ActiveRecord::Base
has_one :client_profile # or whatever a client has here
has_one :trainer_profile # or whatever a trainer has here
end
Then, you would define your abilities
class Ability
include CanCan::Ability
def initialize(user)
user ||= User.new # anonymous user
if user.is? :trainer
can :create, TrainerProfile
# some other trainer specific roles here, like editing his/her profile
elseif user.is? :client
can :create, ClientProfile
# some other client specific roles here, like editing his/her profile
end
end
end
Of course, the above code assumes an is? method on the User class to check the user role.
More info on CanCan can be found on the CanCan wiki, and also the Railscast on CanCan.

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