Using Core Data with SwiftUI

Question

I'm making progress learning SwiftUI but I'm getting stuck when it comes to using it with Core Data.

• Model Objects - I made a couple of entities with the required properties and relationships
• ??? I have no idea where to begin. How to I get SwiftUI talking to Core Data?
• SwiftUI - I have some basic layouts working and showing data from some temp classes, but these have no awareness of Core Data

I've spend the last few days searching and reading everything I can on this topic but I have no idea how to begin to solve this.

Can anyone outline the basic steps to using Core Data with SwiftUI?

Update:

I got some additional feedback on Twitter and one dev suggested that SwiftUI lists may not be suitable for working with Core Data with large data sets. Read the post here: https://twitter.com/numist/status/1141012785825845248

Here is the approach I'm going to take in my app.

• List Views:
  • UITableViewController (with a FetchedResultsController)
  • Manage the connection to Core Data store
  • Use dependency injection to pass records to a detail view
• Detail / Edit Views:
  • When possible build these with UIHostingController
  • Use SwiftUI Forms to make simple data entry forms
  • Receive data via dependency injection
  • Copy data to a temporary BindableObject type
    • Make local UI chances to the temp record
    • Save the temp data back to the actual record on exit

Update 2 - 2019.08.14

Xcode beta 5 has some new Core Data features. I used the information in this blog post to get most of what I need.

Answer 1

You can write a wrapper for your Core-Data logic, like EntityManager and then use it inside BindableObject

class PersonStore: BindableObject {
  var didChange = PassthroughSubject<Void, Never>()

  var persons: [PersonEntity] = [] {
      didSet {
          didChange.send(())
      }
  }

  func fetchPersons(matching name: String) {
    // make you core data query here and assign it to persons property
  }
}

As soon as you query finish and value assigned to persons property SwiftUI will reload View to read new values.