Rails, Devise, CanCan or Declarative authorization -

i developing app in ruby on rails, , reached point don't know best solution fallowing scenario. far able create users, create projects, associate users (something on fb), able invite users website , allow users give different levels of access projects created, other users(something similar github). users after creating account role of superadmin, able manage on projects, or assign projects associates. best option between cancan , declarative authorization. need table store user_id, role_id, , project_id if use cancan or declarative authorization?

thank you

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i explain problem better. far have user (with devise) able create projects. so, if user1 creates project , project b want him, able assign user2 role admin on project a, , user2 moderator role on project b. thinking in creating userroleproject link table, idea? or if not please me pointers.

the action like, user1 select list user2, select project list(that user1 created), , select role user2 have on project.

any user able perform same action on projects. there n projects , n users , 3 access levels(admin, moderator, guest)

thank you

i once made huge app allot of roles , each role had sets of available actions, , used devise , cancan , work charm, integrate quite , both have great documentation.

for other question can

project model:

has_one :user has_many :collaborators, :through => :team 

team model:

belongs_to :user belongs_to :project