Rolify and Rails 4 role management - ruby-on-rails-4

Question

I am trying to implement a role based access system in my rails 4 app, and I want the end user (super_admin) to have the ability to edit role assignments via the UI.
I have achieved some success but can't help feeling that there has to be a better way (Since I'm new to rails). Here is my code:
users_roles_controller.rb
# GET /user_roles/new/:id
def new
#roles = Role.all
end
# POST /user_roles/new/:id
def create
populated = params[:roles][:name].reject(&:empty?)
populated.each do |key|
#user.add_role Role.find(key).name
end
redirect_to users_path
end
And in my Form (HAML and simple_form):
= simple_form_for :roles, :url => create_user_roles_path(#user.id), :method => "post" do |f|
= f.input :name, :collection => #roles, as: :check_boxes
= f.button :submit
I'm struggling with the following:
How do I validate form entries, since there is no model?
Should I be using strong parameters and if so how do I implement on a form without a model
How do I create something similar, but with Current roles already checked? (True role management)
UPDATE
I have looked at using the reform Gem as suggested by the comments. This seems like a great solution. I am however having issues with the implementation on this case.
Let me map it out:
I have 3 tables in the database:
users
users_roles (Mapping Table with 2 Attributes : user_id & role_id {Join Table -> HABTM})
roles
I want to construct a form with all the values in the Roles model as checkboxes.The checkboxes should dictate what values are fed into the users_roles table (With relation to a specific user). What I want reform to do is validate the input of this form. This form will always display all of the values in Roles, but some/all of the boxes might be unchecked.
I have created a form folder in my app and started with the following code:
class UserRoleForm < Reform::Form
property :user__id, on: :user
property :role_id, on: :role
validates :user__id, presence: true
validates :role__id, presence: true
end
Am I going in the right direction?
Thanks for the help.

Answer 1

You need two things to build your form: a user's roles and the possible roles.
If I recall correctly, rolify gives your model associations ad should just let you do something like some_user.roles to return all the roles applied to some_user.
To get possible roles, try Role.all.
To combine both, try
user_roles = some_user.roles.pluck(:name) # suppose this returns ["admin"]
Role.pluck(:name).map { |r| [r, user_roles.include?(r)] }
You now have an array like this that you can use to build your form checkboxes with an each loop.
[["customer", false], ["admin", true], ["editor", false]]
Define your reform object's sync or save method to handle what to do with the submitted input, however you are handling it. You can (SHOULD) make a custom validation to verify if the submitted roles are valid roles.