SwiftDataPreviewer

SwiftDataPreviewer is a lightweight Swift package designed to simplify SwiftUI previews using SwiftData. It provides an in-memory model container for use in DEBUG builds, allowing you to preview your SwiftData-powered views with sample data.

• Seamless SwiftData Previews: Easily inject a ModelContainer into your SwiftUI previews.
• In-Memory Storage: Prevents persistent data pollution while testing.
• Automatic Sample Data Insertion: Quickly preview lists and other data-driven views.
• Developer-Friendly API: Just wrap your view with SwiftDataPreviewer.

Add SwiftDataPreviewer to your Swift project using Swift Package Manager.

dependencies: [
  .package(url: "https://github.com/markbattistella/SwiftDataPreviewer", from: "1.0.0")
]

Alternatively, you can add SwiftDataPreviewer using Xcode by navigating to File > Add Packages and entering the package repository URL.

1. Define a SwiftData Model

   Ensure your SwiftData model conforms to PersistentModel:

   import SwiftData
   
   @Model
   class User {
     @Attribute(.unique) var id: UUID
     var name: String
   
     init(id: UUID = UUID(), name: String) {
       self.id = id
       self.name = name
     }
   }

2. Create a Preview Container

   Define a PreviewContainer with the model types you want to include:

   #if DEBUG
   import SwiftDataPreviewer
   
   let previewContainer = PreviewContainer([User.self])
   #endif

3. Use SwiftDataPreviewer in Your Previews

   Wrap your SwiftUI view in SwiftDataPreviewer and pass sample data:

   #if DEBUG
   import SwiftUI
   import SwiftData
   
   struct UserListView: View {
     @Query private var users: [User]
   
     var body: some View {
       List(users) { user in
         Text(user.name)
       }
     }
   }
   
   struct UserListView_Previews: PreviewProvider {
     static var previews: some View {
       SwiftDataPreviewer(preview: previewContainer, items: [
         User(name: "Alice"),
         User(name: "Bob"),
         User(name: "Charlie")
       ]) {
         UserListView()
       }
     }
   }
   #endif

1. PreviewContainer creates an in-memory ModelContainer.

2. SwiftDataPreviewer injects the container into your SwiftUI view.

3. Sample data is automatically inserted so your previews are populated.

Contributions are welcome! If you find a bug or have suggestions for improvements, feel free to submit a pull request.

SwiftDataPreviewer is available under the MIT licence. See the LICENCE file for more details.