Your Second iOS & SwiftUI App
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To recap, we’re going to let users delete books from their library in two ways: first, the swipe action we already set up, and second, via an edit button.
🟩.onDelete(perform: { indexSet in
/*@START_MENU_TOKEN@*//*@PLACEHOLDER=Code@*/ /*@END_MENU_TOKEN@*/
})
.labelStyle...
}
BookRow(book: $0)
}
.onDelete { indexSet in
}
}
func deleteBook🟩s🟥() {
func deleteBooks(🟩atOffsets offsets: IndexSet) {
func deleteBooks(atOffsets offsets: IndexSet🟩, section: Section) {
sortedBooks[section]
// TODO: Remove Image
sortedBooks[section]?.remove(atOffsets: <#T##IndexSet#>)
remove(atOffsets: offsets)
var sortedBooks: [Section: [Book]] 🟩{
get {
...
}
set {
}
}🟥
set {
🟩booksCache =
sortedBooks
.sorted { $1.key == .finished }
.flatMap { $0.value }
set {
booksCache = newValue
}
func deleteBooks(atOffsets offsets: IndexSet, section: Section?) {
🟩let booksBeforeDeletion = booksCache
sortedBooks.remove(atOffsets: offsets)
}
🟩booksCache.difference(from: booksBeforeDeletion)
}
for change in booksCache.difference(from: booksBeforeDeletion) {
}
}
for change in booksCache.difference(from: booksBeforeDeletion) {
switch change {
}
}
for change in booksCache.difference(from: booksBeforeDeletion) {
switch change {
case .insert(offset: let offset, element: let element, associatedWith: let associatedWith):
<#code#>
case .remove(offset: let offset, element: let element, associatedWith: let associatedWith):
<#code#>
}
}
switch change {
case .remove(offset: let offset, element: let element, associatedWith: let associatedWith):
<#code#>
}
if case .remove(offset: let offset, element: let element, associatedWith: let associatedWith)💰 = change {
<#code#>
}
if case .remove(_, let element, _) = change {
(_, let deletedBook, _)
if case .remove(_, let deletedBook, _) = change {
uiImages[deletedBook] = nil
}
.swipeActions(edge: .trailing) {
Button(role: .destructive) {
guard let index = books.firstIndex(where: {$0.id == book.id})
else { return }
withAnimation {
library.deleteBooks(atOffsets: .init(integer: index), section: section)
}
.onDelete { indexSet in
withAnimation {
library.deleteBooks(atOffsets: .init(integer: index), section: section)
}
}
ForEach(Section.allCases, id: \.self) {
SectionView(section: $0)
}
}
🟩.toolbar(content: <#T##() -> ToolbarContent#>)
.navigationTitle("My Library")
.toolbar(content: 🟩EditButton.init)
.onDelete { indexSet in
...
}
.onMove { indices, newOffset in
}
}
}
func moveBooks(
) {
}
/// Load, save, or delete an image corresponding to a book's title and author.
func moveBooks(
oldOffsets: IndexSet
) {
func moveBooks(
oldOffsets: IndexSet, newOffset: Int
) {
func moveBooks(
oldOffsets: IndexSet, newOffset: Int,
section: Section
) {
section: Section
) {
sortedBooks[section]
}
) {
sortedBooks[section]?.move(fromOffsets: oldOffsets, toOffset: newOffset)
}
.onMove { indices, newOffset in
library.moveBooks(
oldOffsets: indices, newOffset: newOffset,
section: section
)
}