have a SwiftUI View where I can edit financial transaction information. The data is stored in SwiftData. If I enter a TextField element and start typing, it is super laggy and there are hangs of 1-2 seconds between each input (identical behaviour if debugger is detached). On the same view I have another TextField that is just attached to a @State variable of that view and TextField updates of that value work flawlessly. So somehow the hangs must be related to my SwiftData object but I cannot figure out why.
This used to work fine until a few months ago and then I could see the performance degrading.
I have noticed that when I use a placeholder variable like
@State private var transactionSubject: String = ""
and link that to the TextField, the performance is back to normal. I am then using
.onSubmit {
self.transaction.subject = self.transactionSubject
}
to update the value in the end but this again causes a 1 s hang. :/
Below the original code sample with some unnecessary stuff removed:
struct EditTransactionView: View {
@Environment(\.modelContext) var modelContext
@Environment(\.dismiss) var dismiss
@State private var testValue: String = ""
@Bindable var transaction: Transaction
init(transaction: Transaction) {
self.transaction = transaction
let transactionID = transaction.transactionID
let parentTransactionID = transaction.transactionMasterID
_childTransactions = Query(filter: #Predicate<Transaction> {item in
item.transactionMasterID == transactionID
}, sort: \Transaction.date, order: .reverse)
_parentTransactions = Query(filter: #Predicate<Transaction> {item in
item.transactionID == parentTransactionID
}, sort: \Transaction.date, order: .reverse)
print(_parentTransactions)
}
//Function to keep text length in limits
func limitText(_ upper: Int) {
if self.transaction.icon.count > upper {
self.transaction.icon = String(self.transaction.icon.prefix(upper))
}
}
var body: some View {
ZStack {
Form{
Section{
//this one hangs
TextField("Amount", value: $transaction.amount, format: .currency(code: Locale.current.currency?.identifier ?? "USD"))
//this one works perfectly
TextField("Test", text: $testValue)
HStack{
TextField("Enter subject", text: $transaction.subject)
.onAppear(perform: {
UITextField.appearance().clearButtonMode = .whileEditing
})
Divider()
TextField("Select icon", text: $transaction.icon)
.keyboardType(.init(rawValue: 124)!)
.multilineTextAlignment(.trailing)
}
}
}
.onDisappear(){
if transaction.amount == 0 {
// modelContext.delete(transaction)
}
}
.onChange(of: selectedItem, loadPhoto)
.navigationTitle("Transaction")
.navigationBarTitleDisplayMode(.inline)
.toolbar{
Button("Cancel", systemImage: "trash"){
modelContext.delete(transaction)
dismiss()
}
}
.sheet(isPresented: $showingImagePickerView){
ImagePickerView(isPresented: $showingImagePickerView, image: $image, sourceType: .camera)
}
.onChange(of: image){
let data = image?.pngData()
if !(data?.isEmpty ?? false) {
transaction.photo = data
}
}
.onAppear(){
cameraManager.requestPermission()
setDefaultVendor()
setDefaultCategory()
setDefaultGroup()
}
.sheet(isPresented: $showingAmountEntryView){
AmountEntryView(amount: $transaction.amount)
}
}
}
}
