ruby on rails - Filtering archives with access groups with cancancan -

the user log in , able access archive if group user can view archive. archive can viewed many groups. groups , users compose them, determined administrator. how see if logged in user can see archive?

i'm using cancancan gem use skill, tried filter this:

can :read, archive, group: {id: user.group_ids} can :read, archive, group: {archive.joins(:groups).ids} can :read, archive, id: {archive.joins(:groups).ids} can :read, archive, id => {archive.joins(:groups).ids} can :read, archive, :id => {archive.where(group_user:(id: user.group_ids).pluck(:id))} can :read, archive, :group_users {:id => user.group_user_ids }     module ability      can :read, archive |a|        a.archive_group.include?(user.archive_group)      end    end 

but none of above succeeded.

my schema:

  create_table "archives", force: :cascade |t|     t.string   "name"     t.datetime "created_at", null: false     t.datetime "updated_at", null: false   end    create_table "archives_groups", id: false, force: :cascade |t|     t.integer "archive_id", null: false     t.integer "group_id",   null: false   end    create_table "groups", force: :cascade |t|     t.string   "name"     t.datetime "created_at", null: false     t.datetime "updated_at", null: false   end    create_table "groups_users", id: false, force: :cascade |t|     t.integer "group_id", null: false     t.integer "user_id",  null: false   end    create_table "users", force: :cascade |t|     t.string   "name"     t.integer  "kind"     t.datetime "created_at", null: false     t.datetime "updated_at", null: false   end 

models:

class user < activerecord::base   # include default devise modules. others available are:   # :confirmable, :lockable, :timeoutable , :omniauthable   devise :database_authenticatable, :registerable,          :recoverable, :rememberable, :trackable, :validatable     enum kind: [:admin, :user]     has_and_belongs_to_many :groups end  class group < activerecord::base     has_and_belongs_to_many :users     has_and_belongs_to_many :archives end  class archive < activerecord::base     has_and_belongs_to_many :groups end 

for ability.rb can use if , call methods model (user)

class ability   include cancan::ability    def initialize(user)     if user       can :read, archive if user.has_group_membership?(:id)     end   end end 

inside user.rb, create method archive_id params, compare loop if user group ids archive id

def has_group_membership?(archive_id)   token = false   @archive = archive.find(archive_id)   self.groups.each |group|     # loop group user has      @archive.groups.each |ar_group|       # loop group archive has       if group.name.to_sym == ar_group.name.to_sym         # compare symbol (faster string)         token = true         break       end     end   end   return token end