cancancan get all dynamic permissions

I'm writing API where I need to expose all available permissions with ids and other info to an api user.

I have the following structure

class User < ApplicationRecord
  has_many :permissions, dependent: :destroy
end

class Permission < ApplicationRecord
  belongs_to :user, dependent: :destroy
end

and I have ability


class Ability
  include CanCan::Ability

  def initialize(user)
    user_permissions(user)
    dynamic_permissions(user)
  end

  def user_permissions(user)
    can :manage, :dashboard if user.admin?
  end

  def dynamic_permissions(user)
    user.permissions.each do |permission|
    #...
      next branch_permissions(permission) if permission.subject_class == 'branch'
    end
  end

  def branch_permissions(permission)
    can permission.action.to_sym, Branch, id: permission.allowed_ids
  end

and in controller I want to achieve all permissions => can and cannot possible for that user. I have checked docs already and found #permissions. But that doesn't work for dynamic permissions that I have for branch

So I expect the following to be done in cancancan way, providing pseudo-code

  Ability.new(User.find(params[:id]).dynamic_permissions =>
  # {:can=>{:manage=>{"dashboard"=>[]}, :read=>{"Branch"=>['id1', 'id2']}, :index=>{"Branch"=>['id1', 'id2']}, :show=>{"Branch"=>['id1', 'id2']}}, :cannot=>{}}

Current #permissions cancancan method returns only static permissions that are hardcoded to ability file missing all dynamic evaluation.

{:can=>{:manage=>{"dashboard"=>[]}, :read=>{"Branch"=>[]}, :index=>{"Branch"=>[]}, :show=>{"Branch"=>[]}}, :cannot=>{}}

I know I can modify and write custom method that will fetch all of that, but I'm wondering what is accepted approach achieving this.

Solution

ok, it was actually simple. Reading sources helped.

  def branch_permissions(permission)
    can permission.action.to_sym, Branch, id: permission.allowed_ids
  end

this code should be changed to

  def branch_permissions(permission)
    can permission.action.to_sym, Branch, id: permission.allowed_ids.map(&:to_sym)
  end

This method parse_attributes_from_extra_args will treat symbols as attributes for internal state, and then in permissions will show this as I expected. You can serialize those symbols to string then

#  Ability.new(User.find(params[:id]).permissions
=> {:can=>{:manage=>{"dashboard"=>[]}, :read=>{"Branch"=>[:id1, :id2]}, :index=>{"Branch"=>['id1', 'id2']}, :show=>{"Branch"=>[:id1', :id2]}}, :cannot=>{}}