how to make realm CRUD operation in separate swift file? - ios

Question

I am a beginner in iOS development and in programming, I am trying to make a swift file that contain realm CRUD operation called RealmService , so I don't have to write do catch block and try! realm all over the place, like my code below
import Foundation
import RealmSwift
class RealmService {
var realm = try! Realm()
func save(_ object: Object) {
do {
try realm.write {
realm.add(object)
}
} catch {
print("Failed to save \(object) in realm: \(error.localizedDescription)")
}
}
func load(_ object: Object) -> Results<Object>? {
return realm.objects(object.self)
}
func update(_ object: Object, with dictionary: [String: Any?]) {
do {
try realm.write {
for (key, value) in dictionary {
object.setValue(value, forKey: key)
}
}
} catch {
print("Failed to update \(object) in realm: \(error.localizedDescription)")
}
}
func delete(_ object: Object) {
do {
try realm.write {
realm.delete(object)
}
} catch {
print("Failed to delete \(object) in realm: \(error.localizedDescription)")
}
}
}
but in the load method, I get an error in the line realm.objects(object.self) , it is said
Cannot convert value of type 'Object' to expected argument type
'Object.Type'
I think I make mistake when insert object.self in the realm.objects. it should be element.type, but I dont have a clue what is this element type like this picture
how to load data from realm? sadly i just know a little bit from youtube tutorial by using realm.objects(object.self)

Answer 1

You are doing the work of select through an object and this is a mistake because it is required of the type of object Element.Type and not the object itself
try to use this
func load<T: Object>(ofType: T.Type) -> Results<T> {
return realm.objects(T.self)
}
call this func
class MyObject: Object {
...
#objc dynamic var name = ""
...
}
.....
ream.objects(MyObject.self)

Answer 2

I use ReamManager with CRUD like this:
import UIKit
import RealmSwift
class RealmManager {
private let NotificationError = Notification.Name.Realm.realmErrorNotification
var realm = try! Realm()
func create<T: Object>(_ object: T) {
do {
try realm.write {
realm.add(object, update: true)
}
} catch {
post(error)
}
}
func create<T: Object>(_ objects: [T]) {
do {
try realm.write {
realm.add(objects, update: true)
}
} catch {
post(error)
}
}
func read<T: Object>(_ object: T.Type) -> Results<T> {
let result = realm.objects(object.self)
return result
}
func update<T: Object>(_ object: T, with dictionary: [String: Any]) {
do {
try realm.write {
for (key, value) in dictionary {
object.setValue(value, forKey: key)
}
}
} catch {
post(error)
}
}
func delete<T: Object>(_ object: T) {
do {
try realm.write {
realm.delete(object)
}
} catch {
post(error)
}
}
func post(_ error: Error) {
NotificationCenter.default.post(name: NotificationError, object: error)
}
func observeRealErrors(in viewController: UIViewController, complation: #escaping (Error?) -> Void) {
NotificationCenter.default.addObserver(forName: NotificationError, object: viewController, queue: nil) { (notification) in
complation(notification.object as? Error)
}
}
func stopObserveRealErrors(in viewController: UIViewController) {
NotificationCenter.default.removeObserver(viewController, name: NotificationError, object: nil)
}
}
maybe that's exactly what you wanted