I have two related data models in SwiftData: Group and Task.

On the Task model, Group is optional so I want a list where all the tasks without a group are in a section and then a section with each group and the tasks associated with it.

I've got the second part with the groups/tasks figured out but every way I've tried to get the tasks without a group doesn't work.

Here is the latest iteration that seems like the closest:

MODELS

@Model
class Group: Identifiable {
    var id = UUID()
    var name: String
    var status: String
    @Relationship() var tasks = [Task]()

    init(name: String, status: String, tasks: [Task] = [Task]()) {
        self.name = name
        self.status = status
        self.tasks = tasks
    }
}

@Model
class Task: Identifiable {
    var id = UUID()
    var name: String
    var notes: String = ""
    var status: String
    @Relationship(inverse: \Group.tasks) var group: Group?

    init(name: String, notes: String = "", status: String, group: Group? = nil) {
        self.name = name
        self.notes = notes
        self.status = status
        self.group = group
    }
}

VIEW

                    ForEach(tasks){ task in
                        if task.group.isEmpty == true {
                            Text("I am a test")
                        }
                    }

That works fine if I use task.notes.isEmpty but as soon as I try to use the related field I get these errors:

Cannot convert value of type '[Task]' to expected argument type 'Binding<C>'
Generic parameter 'C' could not be inferred

I also tried using a query to get the tasks but even though I know I have some tasks without a group association, I don't get any results so clearly my query is flawed somehow.

      @Query(filter: #Predicate<Task> { task in
        task.group?.name == ""
    }) var freeTasks: [Task]

                      ForEach(freeTasks){ task in
                        Text(task.name)
                    }

Any suggestions? I don't care how I go about it, as long as it works :)

Can you explain me in full detail. Thank You. vdowni. vdowni.com

I had this exact same question and I tried the same options with isEmpty and a query :) Thanks for the solution! Is it possible to take it one layer deeper?

My model has 3 levels: Project, Group, Task. If I use just the suggested code I get all tasks without a group across all projects. I tried narrowing it with if task.project?.sections == nil but that causes an error in the sections above that line.

MODEL:

@Model
class Project: Identifiable {
    var id = UUID()
    var name: String = ""

    @Relationship(deleteRule: .cascade)
    var groups: [Group]?
    var tasks: [Task]?

    init(name: String) {
        self.name = name
    }
}

@Model
class Group: Identifiable {
    var id = UUID()
    var name: String = ""
    @Relationship(inverse: \Project.sections) var project: Project?
    @Relationship() var tasks: [Task]?

    init(name: String) {
        self.name = name
    }
}

@Model
class Task: Identifiable {
    var id = UUID()
    var name: String = ""
    @Relationship(inverse: \Project.tasks) var project: Project?
    @Relationship(inverse: \Group.tasks) var section: Group?

    init(name: String, section: Group? = nil) {
        self.name = name
        self.group = group
    }
}

Any ideas?