Can someone provide better contains() usage documentation?

[rromanchuk]

Equivalent to the IN operator. Evaluates to true if the property referenced by the expression contains the value.

I don't understand how the example is showing, what i assumed would be a typed equivalent to .filter("assignee IN %@", ["Ali", "Jamie"])

let aliOrJamiesTasks = tasks.where {
    $0.assignee.contains("Ali") || $0.assignee.contains("Jamie")
}
print("Tasks IN Ali or Jamie: \(aliOrJamiesTasks.count)")

This just seems like a much more annoying way to write .where { $0.assignee == "Ali" || $0.assignee == "Jamie" }

For example, how would you compose .filter("challenge.id == %@ && (status IN %@ || gave_up == true)", challengeId, [PlayerStatus.kicked_out.rawValue, PlayerStatus.left.rawValue])

class Player: Object, JapxDecodable, WithSaveHooks {
  enum PlayerStatus: String, Codable, PersistableEnum, _Indexable {
    case joined
    case left
    case kicked_out
    case loser
    case winner
    case unknown
  }
  
  @Persisted(primaryKey: true) var id = ""
  @Persisted(indexed: true) var status = PlayerStatus.joined
  @Persisted var challenge: Challenge?
}

I would assume the block would look something like this.where { [.left, .kicked_out].contains($0.status) } If anyone has more realistic examples to get me going, before I head to the reference docs, which is dense with generics, i'll give you a 🥇

[leemaguire]

I think what you want is containsAny(in:). So you would do something like:

.where { $0.assignee.containsAny(in: ["Ali", "Jamie"]) }

This produces the NSPredicate string "(ANY assignee IN %@)".

[rhys-rant]

I'm having a similar problem to this.
My equivalent of

realm.objects(Player.self).where { player in
  player.status

code doesn't give me .containsAny(in:) as an option.

I only get .contains(range: (Closed)Range<Player.PlayerStatus>) as options. I get No exact matches in reference to subscript as the error.

[leemaguire]

@rhys-rantmedia containsAny(in:) is for collection properties. Can you show an example of what you are trying to achieve?

[rhys-rant]

I thought as much.
So say I have the following types:

class Order: Object {
  @Persisted var name: String
  @Persisted var date: Date = Date()
  @Persisted var status: Status
}

enum Status: Int, PersistableEnum {
  case inProgress
  case delivered
  case cancelled
}

With the NSPredicate style, if I want to get all Order objects which are either .delivered or .cancelled, I would write something like this:

realm.objects(Order.self)
  .filter("status IN %@", [Status.delivered.rawValue, Status.cancelled.rawValue])

How do I do the equivalent with the type-safe Query, if it's currently even possible? As @rromanchuk said, it seems like the logical syntax would be something like:

realm.objects(Order.self)
  .where { order in [.delivered, .cancelled].contains(order.status) }

or something along those lines. But that's not possible, because order.status is type Query<Status>.

Is there a method on Query that I'm missing so I can write something like

realm.objects(Order.self)
  .where { order in order.status.in([.delivered, .cancelled]) }

[leemaguire]

That is not a valid use of IN in this scenario. IN should be used with collection types. I suggest:

realm.objects(Order.self)
            .where { order in order.status == .delivered || order.status == .cancelled }

[rhys-rant]

That is not a valid use of IN in this scenario. IN should be used with collection types. I suggest:

realm.objects(Order.self)
            .where { order in order.status == .delivered || order.status == .cancelled }

I guess that's the problem - the NSPredicate IN query works fine. I can check if a single value on the left-hand side is IN an array/list/set that's the right-hand side using an NSPredicate.

The more real-world example is I have a method that is currently structured like this:

func allOrders(statuses: [Status] = [], searchTerms: String) -> Results<Status> {
  var results = realm.objects(Order.self)
    .filter("status IN %@", statuses)

  // More filtering here, using searchTerms

  return results
}

and have done similar in other applications without issue. I'd like to be able to pass in, at allOrders call-time, the statuses I'm filtering by, given other (non-trivial) work happens after that initial filter takes place. That's why I can't just use multiple || statements inside the where.

Ideally, I'd like to be able to do something more like statuses.contains(order.status) (where collection is the non-Query-wrapped type), or have a method on Query to check against multiple possible values, generating NSPredicate string "status IN {2, 3}"

The same behaviour - value IN collection - works in older Cocoa APIs as expected FWIW, as demo'd here: https://gist.github.com/rhys-rantmedia/20250d8bd79a7e0cff67aaf970490980 so I think my use of IN is appropriate, at least with regards to how Foundation handles NSPredicates.

Either this just isn't possible right now, and I guess this is a feature request, or there's just something I'm missing 😄

[rromanchuk]

Didn't realize there were replies to this. @rhys-rantmedia same, i have quite a bit of NSPredicate usage using status IN %@ too. Did you poke around this issue any more?