How can I check resource permission with resource attribute ?

[edocevol]

definition user {
}

caveat is_public(public bool) {
  public
}

definition resource {
+ attribue is_public: bool
- relation viewer: user | resource with is_public
  relation writer: user

+ permission view = viewer +  writer + resource->is_public
}

Is is so expensive for every turple write with caveat context, cause the is_public is a attribute for resource but not for user.

[vroldanbet]

We don't typically recommend using caveat for this because it is not a dynamic aspect of the resource - caveats were designed to be used for anything that can only be defined at request time (think anything that comes along your application's API request).

You can easily model this using wildcards:

definition user {}

definition resource {
  relation public: user:*
  relation viewer: user
  relation writer: user

  permission view = viewer +  writer + public
}