.OnDelete not working with Realm data, How can I fix this? - swift

Question

When I run my app and try swiping, the onDelete does not appear and doesn't work. I haven't had the chance to really test if it deletes or not because when I swipe it doesn't allow me to try deleting it. I am using RealmSwift and posted the code for the view as well as the ViewModel I use. Sorry if this isn't enough code, let me know and I'll link my GitHub repo, or share more code.
import SwiftUI
import RealmSwift
import Combine
enum ActiveAlert{
case error, noSauce
}
struct DoujinView: View {
#ObservedObject var doujin: DoujinAPI
// #ObservedResults(DoujinInfo.self) var doujinshis
#State private var detailViewShowing: Bool = false
#State private var selectedDoujin: DoujinInfo?
#StateObject var doujinModel = DoujinInfoViewModel()
var body: some View {
//Code if there are any Doujins
ScrollView(.vertical) {
LazyVStack(spacing: 0) {
ForEach(doujinModel.doujins, id: \.UniqueID) { doujinshi in
Button(action: {
self.detailViewShowing = true
self.doujinModel.selectedDoujin = doujinshi
}) {
DoujinCell(image: convertBase64ToImage(doujinshi.PictureString))
}
}
.onDelete(perform: { indexSet in
self.doujinModel.easyDelete(at: indexSet)
})
//This will preseent the sheet that displays information for the doujin
.sheet(isPresented: $detailViewShowing, onDismiss: {if doujinModel.deleting == true {doujinModel.deleteDoujin()}}, content: {
DoujinInformation(theAPI: doujin, doujinModel: doujinModel)
})
// Loading circle
if doujin.loadingCircle == true{
LoadingCircle(theApi: doujin)
}
}
}
}
}
enum colorSquare:Identifiable{
var id: Int{
hashValue
}
case green
case yellow
case red
}
class DoujinInfoViewModel: ObservableObject{
var theDoujin:DoujinInfo? = nil
var realm:Realm?
var token: NotificationToken? = nil
#ObservedResults(DoujinInfo.self) var doujins
#Published var deleting:Bool = false
#Published var selectedDoujin:DoujinInfo? = nil
#Published var loading:Bool = false
init(){
let realm = try? Realm()
self.realm = realm
token = doujins.observe({ (changes) in
switch changes{
case .error(_):break
case .initial(_): break
case .update(_, deletions: _, insertions: _, modifications: _):
self.objectWillChange.send() }
})
}
deinit {
token?.invalidate()
}
var name: String{
get{
selectedDoujin!.Name
}
}
var id: String {
get {
selectedDoujin!.Id
}
}
var mediaID:String {
get {
selectedDoujin!.MediaID
}
}
var numPages:Int{
get {
selectedDoujin!.NumPages
}
}
var pictureString:String {
get {
selectedDoujin!.PictureString
}
}
var uniqueId: String{
get{
selectedDoujin!.PictureString
}
}
var similarity:Double{
get {
selectedDoujin!.similarity
}
}
var color:colorSquare{
get{
switch selectedDoujin!.similarity{
case 0...50:
return .red
case 50...75:
return .yellow
case 75...100:
return .green
default:
return .green
}
}
}
var doujinTags: List<DoujinTags>{
get {
selectedDoujin!.Tags
}
}
func deleteDoujin(){
try? realm?.write{
realm?.delete(selectedDoujin!)
}
deleting = false
}
func easyDelete(at indexSet: IndexSet){
if let index = indexSet.first{
let realm = doujins[indexSet.first!].realm
try? realm?.write({
realm?.delete(doujins[indexSet.first!])
})
}
}
func addDoujin(theDoujin: DoujinInfo){
try? realm?.write({
realm?.add(theDoujin)
})
}
}

Answer 1

.onDelete works only for List. For LazyVStack we need to create our own swipe to delete action.
Here is the sample demo. You can modify it as needed.
SwipeDeleteRow View
struct SwipeDeleteRow<Content: View>: View {
private let content: () -> Content
private let deleteAction: () -> ()
private var isSelected: Bool
#Binding private var selectedIndex: Int
private var index: Int
init(isSelected: Bool, selectedIndex: Binding<Int>, index: Int, #ViewBuilder content: #escaping () -> Content, onDelete: #escaping () -> Void) {
self.isSelected = isSelected
self._selectedIndex = selectedIndex
self.content = content
self.deleteAction = onDelete
self.index = index
}
#State private var offset = CGSize.zero
#State private var offsetY : CGFloat = 0
#State private var scale : CGFloat = 0.5
var body : some View {
HStack(spacing: 0){
content()
.frame(width : UIScreen.main.bounds.width, alignment: .leading)
Button(action: deleteAction) {
Image("delete")
.renderingMode(.original)
.scaleEffect(scale)
}
}
.background(Color.white)
.offset(x: 20, y: 0)
.offset(isSelected ? self.offset : .zero)
.animation(.spring())
.gesture(DragGesture(minimumDistance: 30, coordinateSpace: .local)
.onChanged { gestrue in
self.offset.width = gestrue.translation.width
print(offset)
}
.onEnded { _ in
self.selectedIndex = index
if self.offset.width < -50 {
self.scale = 1
self.offset.width = -60
self.offsetY = -20
} else {
self.scale = 0.5
self.offset = .zero
self.offsetY = 0
}
}
)
}
}
Demo View
struct Model: Identifiable {
var id = UUID()
}
struct CustomSwipeDemo: View {
#State var arr: [Model] = [.init(), .init(), .init(), .init(), .init(), .init(), .init(), .init()]
#State private var listCellIndex: Int = 0
var body: some View {
ScrollView(.vertical) {
LazyVStack(spacing: 0) {
ForEach(arr.indices, id: \.self) { index in
SwipeDeleteRow(isSelected: index == listCellIndex, selectedIndex: $listCellIndex, index: index) {
if let item = self.arr[safe: index] {
Text(item.id.description)
}
} onDelete: {
arr.remove(at: index)
self.listCellIndex = -1
}
.frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .leading)
}
}
}
}
}
Helper function
//Help to preventing delete row from index out of bounds.
extension Collection where Indices.Iterator.Element == Index {
subscript (safe index: Index) -> Iterator.Element? {
return indices.contains(index) ? self[index] : nil
}
}