What does this line of Ruby/Rails do?

Question

Can you please walk me through the following line of Ruby/Rails?

if user.role? :super_admin

To fit my app, I updated it to:

if user.role? :admin

and that failed, but then I updated it to:

if user.role? == 'admin'

And it works as intended. Why is that?

class Ability
  include CanCan::Ability

  def initialize(user)
    user ||= User.new # guest user

    if user.role? :super_admin
      can :manage, :all
    elsif user.role? :product_admin
      can :manage, [Product, Asset, Issue]
    elsif user.role? :product_team
      can :read, [Product, Asset]
      # manage products, assets he owns
      can :manage, Product do |product|
        product.try(:owner) == user
      end
      can :manage, Asset do |asset|
        asset.assetable.try(:owner) == user
      end
    end
  end
end



def role?(role)
    return !!self.roles.find_by_name(role.to_s.camelize)
end

Answer 1

if user.role? :super_admin

In this line you call the method role? on the object user with the parameter :super_admin (which is a symbol) and check if the method returns true.

If the call to user.role? :admin returns false there might simply be no role named 'admin'.

Reading CanCan's documentation on Role Based Authorization should shed some light on this subject.