Not able to delete and move row at for the item in the list view.
Apple provided in their training video these methods but its not working
For removing:
array.remove(atOffsets: IndexSet)
For moving:
array.move(fromOffsets: IndexSet, toOffset: Int)
Both of these method are not available in the apple documentation.
These methods are part of the Swift 5.1 standard library, which Apple will make available with a future beta of Xcode. In the meantime, you can use these extensions:
extension Array {
mutating func remove(atOffsets offsets: IndexSet) {
let suffixStart = halfStablePartition { index, _ in
return offsets.contains(index)
}
removeSubrange(suffixStart...)
}
mutating func move(fromOffsets source: IndexSet, toOffset destination: Int) {
let suffixStart = halfStablePartition { index, _ in
return source.contains(index)
}
let suffix = self[suffixStart...]
removeSubrange(suffixStart...)
insert(contentsOf: suffix, at: destination)
}
mutating func halfStablePartition(isSuffixElement predicate: (Index, Element) -> Bool) -> Index {
guard var i = firstIndex(where: predicate) else {
return endIndex
}
var j = index(after: i)
while j != endIndex {
if !predicate(j, self[j]) {
swapAt(i, j)
formIndex(after: &i)
}
formIndex(after: &j)
}
return i
}
func firstIndex(where predicate: (Index, Element) -> Bool) -> Index? {
for (index, element) in self.enumerated() {
if predicate(index, element) {
return index
}
}
return nil
}
}
the methods you are refering to are now available on Xcode 11 GM. You can use them like this.
removing an element
TLDR:
.onDelete{offsets in
self.array.remove(atOffsets: offsets)
full code (can copy paste): import SwiftUI
struct MyTableView : View {
@State var array=[1,2,3,4,5]
var body: some View {
List{
ForEach(array,id:\.self){element in
Text("\(element)")
}
.onDelete{offsets in
self.array.remove(atOffsets: offsets)
}
}
}
}
struct MyTableView_Previews : PreviewProvider {
static var previews: some View {
MyTableView()
}
}
moving elements
.onMove { (offsets, targetOffset) in
self.array.move(fromOffsets: offsets, toOffset: targetOffset)
}
They either used custom extensions to Array or some version of Swift not available to the public yet. Workarounds that I implemented are:
delete
func delete(at offsets: IndexSet) {
if let first = offsets.first {
store.rooms.remove(at: first)
}
}
move
func move(from source: IndexSet, to destination: Int) {
if let first = source.first {
store.rooms.swapAt(first, destination)
}
}
Move function works however, the animation is not as good as the one on video at WWDC 2019.
