Mahi Garg

Merge data management seamlessly with UI. Model, persist, and update app data effortlessly using declarative syntax. Fetch, sort, and filter data effortlessly, ensuring a responsive and engaging user experience. Simplify synchronization between data and UI layers for efficient, scalable app development.

Let us understand the setup of Core Data in SwiftUI

Create Core Data Model

Create new file of type Data Model under Core Data.
Add entity by tapping on + button. Then add attributes. Your file will look like below after adding EmployeeModel with EmployeeEntity and name and id as attributes

CoreData in SwiftUI

Create Core View Model

This swift file will contain initialization and methods required to work core data.

Let us give a look on the code.

Initialization of Core Data

import CoreData

class EmployeeViewModel: ObservableObject {
    
    var context: NSPersistentContainer
    @Published var employeeEntity: [EmployeeEntity] = []
    
    init(){
        context = NSPersistentContainer(name: "EmployeeModel")
        context.loadPersistentStores { description, error in
            if let error = error {
                print("error loading: \(error)")
            }
        }
    }
}

Here, EmployeeModel is initialized using NSPersistentContainer.

Fetching Core Data

func fetchData() {
        let request = NSFetchRequest<EmployeeEntity>(entityName: "EmployeeEntity")
        do {
            employeeEntity = try context.viewContext.fetch(request)
        } catch (let error) {
            print("error fetching: \(error)")
        }
    }

Adding data to Core Data Entity

func addData(name: String,
                 id: Int16) {
        let newEmployee = EmployeeEntity(context: context.viewContext)
        newEmployee.id = id
        newEmployee.name = name
        self.saveData()
    }

Saving Core Data

    func saveData() {
        do {
            try context.viewContext.save()
        } catch (let error) {
            print("error saving: \(error)")
        }
    }

Deleting data from Core Data

func deleteData(indexSet: IndexSet) {
        guard let index = indexSet.first else { return }
        let entity = employeeEntity[index]
        context.viewContext.delete(entity)
        self.saveData()
    }

Using Core Data in swiftUI View

Create a @StateObject variable Viewmodel. Use the publised property of Core Data Entity to updae the UI. Publised property of Core Data Entity will work similarly as an data array. Data an be displayed by Using ForEach in stack (HStack or VStack) or List view can also be used to do so.

struct EmployeeView: View {
    
    @StateObject var viewModel = EmployeeViewModel()
    
    /// code

Feel free to refer my demo project on Core Data in SwiftUI coredata-swiftui

Tags: SwiftUI