Is it possible to use SwiftData?

[Floataqq]

I'm really new to swift and i don't really know if it's a bug, so filing without the bug label. Thanks in advance for helping :)

if i do something like this:

import SwiftData

@Model
final class Person {
    var firstName: String
    var lastName: String
	var relatives: [Person] = []
}

compilation will fail with a massive wall of repeating errors like this:

root@48e2171c8734:/ios/tracker# xtool dev
Planning...
[1/1] Planning build
Building for debugging...
error: emit-module command failed with exit code 1 (use -v to see invocation)
/ios/tracker/Sources/tracker/Data.swift:4:13: error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
2 | 
3 | @Model
4 | final class Person {
  |             `- error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
5 |     var firstName: String
6 |     var lastName: String

SwiftData.Model:3:320: note: 'Model()' declared here
1 | @available(swift 5.9)
2 | @available(macOS 14, iOS 17, tvOS 17, watchOS 10, *)
3 | @attached(member, names: named(_$backingData), named(persistentBackingData), named(schemaMetadata), named(init), named(_$observationRegistrar), named(_SwiftDataNoType), named(access), named(withMutation)) @attached(memberAttribute) @attached(extension, conformances: Observable, PersistentModel, Sendable) public macro Model() = #externalMacro(module: "SwiftDataMacros", type: "PersistentModelMacro")
  |                                                                                                                                                                                                                                                                                                                                `- note: 'Model()' declared here

/ios/tracker/Sources/tracker/Data.swift:5:9: error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
3 | @Model
4 | final class Person {
5 |     var firstName: String
  |         `- error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
6 |     var lastName: String
7 |     var relatives: [Person] = []

SwiftData.Model:3:320: note: 'Model()' declared here
1 | @available(swift 5.9)
2 | @available(macOS 14, iOS 17, tvOS 17, watchOS 10, *)
3 | @attached(member, names: named(_$backingData), named(persistentBackingData), named(schemaMetadata), named(init), named(_$observationRegistrar), named(_SwiftDataNoType), named(access), named(withMutation)) @attached(memberAttribute) @attached(extension, conformances: Observable, PersistentModel, Sendable) public macro Model() = #externalMacro(module: "SwiftDataMacros", type: "PersistentModelMacro")
  |                                                                                                                                                                                                                                                                                                                                `- note: 'Model()' declared here

/ios/tracker/Sources/tracker/Data.swift:6:9: error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
4 | final class Person {
5 |     var firstName: String
6 |     var lastName: String
  |         `- error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
7 |     var relatives: [Person] = []
8 | }

SwiftData.Model:3:320: note: 'Model()' declared here
1 | @available(swift 5.9)
2 | @available(macOS 14, iOS 17, tvOS 17, watchOS 10, *)
3 | @attached(member, names: named(_$backingData), named(persistentBackingData), named(schemaMetadata), named(init), named(_$observationRegistrar), named(_SwiftDataNoType), named(access), named(withMutation)) @attached(memberAttribute) @attached(extension, conformances: Observable, PersistentModel, Sendable) public macro Model() = #externalMacro(module: "SwiftDataMacros", type: "PersistentModelMacro")
  |                                                                                                                                                                                                                                                                                                                                `- note: 'Model()' declared here

/ios/tracker/Sources/tracker/Data.swift:7:6: error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
5 |     var firstName: String
6 |     var lastName: String
7 |     var relatives: [Person] = []
  |      `- error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
8 | }

SwiftData.Model:3:320: note: 'Model()' declared here
1 | @available(swift 5.9)
2 | @available(macOS 14, iOS 17, tvOS 17, watchOS 10, *)
3 | @attached(member, names: named(_$backingData), named(persistentBackingData), named(schemaMetadata), named(init), named(_$observationRegistrar), named(_SwiftDataNoType), named(access), named(withMutation)) @attached(memberAttribute) @attached(extension, conformances: Observable, PersistentModel, Sendable) public macro Model() = #externalMacro(module: "SwiftDataMacros", type: "PersistentModelMacro")
  |                                                                                                                                                                                                                                                                                                                                `- note: 'Model()' declared here

/ios/tracker/Sources/tracker/Data.swift:4:13: error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
2 | 
3 | @Model
4 | final class Person {
  |             `- error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
5 |     var firstName: String
6 |     var lastName: String

SwiftData.Model:3:320: note: 'Model()' declared here
1 | @available(swift 5.9)
2 | @available(macOS 14, iOS 17, tvOS 17, watchOS 10, *)
3 | @attached(member, names: named(_$backingData), named(persistentBackingData), named(schemaMetadata), named(init), named(_$observationRegistrar), named(_SwiftDataNoType), named(access), named(withMutation)) @attached(memberAttribute) @attached(extension, conformances: Observable, PersistentModel, Sendable) public macro Model() = #externalMacro(module: "SwiftDataMacros", type: "PersistentModelMacro")
  |                                                                                                                                                                                                                                                                                                                                `- note: 'Model()' declared here

/ios/tracker/Sources/tracker/Data.swift:4:13: error: class 'Person' has no initializers
2 | 
3 | @Model
4 | final class Person {
  |             `- error: class 'Person' has no initializers
5 |     var firstName: String
  |         `- note: stored property 'firstName' without initial value prevents synthesized initializers
6 |     var lastName: String
  |         `- note: stored property 'lastName' without initial value prevents synthesized initializers
7 |     var relatives: [Person] = []
8 | }
/ios/tracker/Sources/tracker/Data.swift:4:13: error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
2 | 
3 | @Model
4 | final class Person {
  |             `- error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
5 |     var firstName: String
6 |     var lastName: String

SwiftData.Model:3:320: note: 'Model()' declared here
1 | @available(swift 5.9)
2 | @available(macOS 14, iOS 17, tvOS 17, watchOS 10, *)
3 | @attached(member, names: named(_$backingData), named(persistentBackingData), named(schemaMetadata), named(init), named(_$observationRegistrar), named(_SwiftDataNoType), named(access), named(withMutation)) @attached(memberAttribute) @attached(extension, conformances: Observable, PersistentModel, Sendable) public macro Model() = #externalMacro(module: "SwiftDataMacros", type: "PersistentModelMacro")
  |                                                                                                                                                                                                                                                                                                                                `- note: 'Model()' declared here

/ios/tracker/Sources/tracker/Data.swift:5:9: error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
3 | @Model
4 | final class Person {
5 |     var firstName: String
  |         `- error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
6 |     var lastName: String
7 |     var relatives: [Person] = []

SwiftData.Model:3:320: note: 'Model()' declared here
1 | @available(swift 5.9)
2 | @available(macOS 14, iOS 17, tvOS 17, watchOS 10, *)
3 | @attached(member, names: named(_$backingData), named(persistentBackingData), named(schemaMetadata), named(init), named(_$observationRegistrar), named(_SwiftDataNoType), named(access), named(withMutation)) @attached(memberAttribute) @attached(extension, conformances: Observable, PersistentModel, Sendable) public macro Model() = #externalMacro(module: "SwiftDataMacros", type: "PersistentModelMacro")
  |                                                                                                                                                                                                                                                                                                                                `- note: 'Model()' declared here

/ios/tracker/Sources/tracker/Data.swift:6:9: error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
4 | final class Person {
5 |     var firstName: String
6 |     var lastName: String
  |         `- error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
7 |     var relatives: [Person] = []
8 | }

SwiftData.Model:3:320: note: 'Model()' declared here
1 | @available(swift 5.9)
2 | @available(macOS 14, iOS 17, tvOS 17, watchOS 10, *)
3 | @attached(member, names: named(_$backingData), named(persistentBackingData), named(schemaMetadata), named(init), named(_$observationRegistrar), named(_SwiftDataNoType), named(access), named(withMutation)) @attached(memberAttribute) @attached(extension, conformances: Observable, PersistentModel, Sendable) public macro Model() = #externalMacro(module: "SwiftDataMacros", type: "PersistentModelMacro")
  |                                                                                                                                                                                                                                                                                                                                `- note: 'Model()' declared here

/ios/tracker/Sources/tracker/Data.swift:7:6: error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
5 |     var firstName: String
6 |     var lastName: String
7 |     var relatives: [Person] = []
  |      `- error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
8 | }

SwiftData.Model:3:320: note: 'Model()' declared here
1 | @available(swift 5.9)
2 | @available(macOS 14, iOS 17, tvOS 17, watchOS 10, *)
3 | @attached(member, names: named(_$backingData), named(persistentBackingData), named(schemaMetadata), named(init), named(_$observationRegistrar), named(_SwiftDataNoType), named(access), named(withMutation)) @attached(memberAttribute) @attached(extension, conformances: Observable, PersistentModel, Sendable) public macro Model() = #externalMacro(module: "SwiftDataMacros", type: "PersistentModelMacro")
  |                                                                                                                                                                                                                                                                                                                                `- note: 'Model()' declared here

/ios/tracker/Sources/tracker/Data.swift:4:13: error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
2 | 
3 | @Model
4 | final class Person {
  |             `- error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
5 |     var firstName: String
6 |     var lastName: String

SwiftData.Model:3:320: note: 'Model()' declared here
1 | @available(swift 5.9)
2 | @available(macOS 14, iOS 17, tvOS 17, watchOS 10, *)
3 | @attached(member, names: named(_$backingData), named(persistentBackingData), named(schemaMetadata), named(init), named(_$observationRegistrar), named(_SwiftDataNoType), named(access), named(withMutation)) @attached(memberAttribute) @attached(extension, conformances: Observable, PersistentModel, Sendable) public macro Model() = #externalMacro(module: "SwiftDataMacros", type: "PersistentModelMacro")
  |                                                                                                                                                                                                                                                                                                                                `- note: 'Model()' declared here

/ios/tracker/Sources/tracker/Data.swift:4:13: error: class 'Person' has no initializers
2 | 
3 | @Model
4 | final class Person {
  |             `- error: class 'Person' has no initializers
5 |     var firstName: String
  |         `- note: stored property 'firstName' without initial value prevents synthesized initializers
6 |     var lastName: String
  |         `- note: stored property 'lastName' without initial value prevents synthesized initializers
7 |     var relatives: [Person] = []
8 | }
[3/6] Compiling tracker Data.swift
Error: exit(1)

is it generally possible to use swiftData, and if no, could you recommend some alternative please?

P.S. probably shouldn't affect anything, but i'm building from a docker container because i couldn't set xtool up on my Nixos host

[kabiroberai]

Unfortunately SwiftData will be tricky to get working because it leverages proprietary macros, which we'd have to re-implement ourselves. There is a path to doing this (see #101) but even once that PR lands someone will need to do the implementation work for the SwiftData macros.

TBH SwiftData is relatively rough atm, and the reviews are pretty mixed. Consider using an alternative like GRDB, which is built upon open source software like SQLite. If you use that with PointFree's SharingGRDB, you end up with a developer experience that's very similar to (if not better than) SwiftData and is more powerful in many ways. Plus, importantly, it should actually work with xtool.

[kabiroberai]

FYI I just built a sample app with SharingGRDB and it seems to work great, but I did find a few bugs in xtool along the way:

1. You'll need to check out the branch corresponding to Enable cross import overlays #153 (at least until I ship a new release with that PR), build xtool from source (make linux-dist), and use the built xtool to update your Swift SDK (xtool sdk install).
   • Or a slightly hackier approach, skip the rebuilding and patch the SDK by hand:

sed -i -r \
  's/(=lld")$/\1, "-Xfrontend", "-enable-cross-import-overlays"/g' \
  "$(swift sdk configure darwin arm64-apple-ios --show-configuration | tail -1 | cut -d'"' -f2)"

2. xtool doesn't handle Package Traits correctly right now, which causes some issues during dependency resolution, but you can fix this by explicitly enabling the StructuredQueriesTagged trait. Your Package.swift should look something like this:

// swift-tools-version: 6.1

import PackageDescription

let package = Package(
    name: "Hello",
    platforms: [
        .iOS(.v17),
        .macOS(.v14),
    ],
    products: [
        .library(
            name: "Hello",
            targets: ["Hello"],
        ),
    ],
    dependencies: [
        .package(
            url: "https://github.com/pointfreeco/swift-structured-queries",
            .upToNextMinor(from: "0.11.0"),
            traits: ["StructuredQueriesTagged"],
        ),
        .package(
            url: "https://github.com/pointfreeco/sharing-grdb",
            .upToNextMinor(from: "0.5.0"),
        ),
    ],
    targets: [
        .target(
            name: "Hello",
            dependencies: [
                .product(name: "SharingGRDB", package: "sharing-grdb"),
            ],
        ),
    ],
)

[Floataqq]

Wow! Thanks for your help :)

I did switch to GRDB in the end (and tried and failed SharingGRBD xd), so i will check out SharingGRDB a bit later

[kabiroberai]

Going to leave this open for now for visibility