FAQ: Handling Optional Values in SwiftData #1

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opened 2024-03-17 09:56:53 +00:00 by skalber-mm · 4 comments

skalber-mm commented

2024-03-17 09:56:53 +00:00

(Migrated from github.com)

I'm getting a crash with the following error:

It looks like the issue is in the currentRoomPredicate, if I remove it from the conjunction array it doesn't crash:

Is there a limit on the allowed nested objects in the predicate? I mean is the problem with contract.listing?.room?.persistentModelID ?

Thank you for the great work making this lib!

I'm getting a crash with the following error: ![image](https://github.com/NoahKamara/CompoundPredicate/assets/14924551/77126aa4-660a-4159-86d1-7e1c3c7fb7c0) It looks like the issue is in the `currentRoomPredicate`, if I remove it from the `conjunction` array it doesn't crash: ![image](https://github.com/NoahKamara/CompoundPredicate/assets/14924551/f05acd37-618f-4d9e-9d6e-9611faf1efa2) Is there a limit on the allowed nested objects in the predicate? I mean is the problem with `contract.listing?.room?.persistentModelID` ? Thank you for the great work making this lib!

NoahKamara commented

2024-03-20 20:15:38 +00:00

(Migrated from github.com)

Thank you for the report :)
It might be an issue with PersistentIdentifier or NilLiteral.

Can you provide a minimal reproducible example?

Thank you for the report :) It might be an issue with `PersistentIdentifier` or `NilLiteral`. Can you provide a [minimal reproducible example](https://stackoverflow.com/help/minimal-reproducible-example)?

NoahKamara commented

2024-03-20 20:35:51 +00:00

(Migrated from github.com)

I am trying to reproduce the issue and am getting a SwiftData crash when trying to access nested relationships:

@Model
class PersonModel {
    @Relationship
    var partner: PersonModel?
}

let nestedRelationshipPredicate = #Predicate<PersonModel> { person in
    person.partner?.partner?.persistentModelID == modelID
}

try context.fetch(.init(predicate: nestedRelationshipPredicate))

This seems to be an issue with SwiftData. I suggest trying to try unwrapping the optionals:

if let listing = contract.listing { ... } else { false }

I would welcome a minimal reproducible example as I am so far unable to reproduce this specific crash

I am trying to reproduce the issue and am getting a SwiftData crash when trying to access nested relationships: ```swift @Model class PersonModel { @Relationship var partner: PersonModel? } let nestedRelationshipPredicate = #Predicate<PersonModel> { person in person.partner?.partner?.persistentModelID == modelID } try context.fetch(.init(predicate: nestedRelationshipPredicate)) ``` This seems to be an issue with SwiftData. I suggest trying to try unwrapping the optionals: ```swift if let listing = contract.listing { ... } else { false } ``` I would welcome a minimal reproducible example as I am so far unable to reproduce this specific crash

skalber-mm commented

2024-03-22 18:48:46 +00:00

(Migrated from github.com)

Yes thanks, managed to solve it by reading this article: https://fatbobman.com/en/posts/how-to-handle-optional-values-in-swiftdata-predicates/

Yes thanks, managed to solve it by reading this article: https://fatbobman.com/en/posts/how-to-handle-optional-values-in-swiftdata-predicates/ ![image](https://github.com/NoahKamara/CompoundPredicate/assets/14924551/aba9ec17-1162-441f-bee1-257e105ead9b)

NoahKamara commented

2024-03-23 12:59:43 +00:00

(Migrated from github.com)

Happy to hear you could solve the issue. I'm closing it but marking it with FAQ for others with the same problem