Why the List does not appear? - swiftui

Why the presetsList does not appear? No errors were thrown though.
import SwiftUI
struct AddMessagePreset: View {
let presetsList = [
Preset(name: "preset text 1"),
Preset(name: "preset text 2"),
Preset(name: "preset text 3")
]
var body: some View {
List(presetsList) { singlePresetModel in
SinglePresetChild (presetModel: singlePresetModel)
}
}
}
import SwiftUI
struct Preset: Identifiable {
let id = UUID()
let name: String
}
struct SinglePresetChild: View {
var presetModel: Preset
var body: some View {
Text("Preset Name \(presetModel.name)")
}
}

UPDATE: To show a List inside another ScrollView (or List), you have to set a height on the inner list view:
struct Preview: View {
var body: some View {
ScrollView {
AddMessagePreset().frame(height: 200)
// more views ...
}
}
}
But let me advise against doing so. Having nested scroll areas can be very confusing for the user.
As discussed in the comments, your component code is fine. However, the way you integrate it into your app causes a problem. Apparently, nesting a List inside a ScrollView does not work properly (also see this thread).
List is already scrollable vertically, so you won't need the additional ScrollView:
struct Preview: View {
var body: some View {
VStack {
AddMessagePreset()
}
}
}
P.S.: If you only want to show AddMessagePreset and won't add another sibling view, you can remove the wrapping VStack; or even show AddMessagePreset as the main view, without any wrapper.

Related

SwiftUI for macOS: Expand clickable area of a TextField in a ForEach view of a List

As a hobby project, I'm developing a SwiftUI app targeted for macOS.
I have a CoreData entity (let's call it Sample) with a String property called title.
In my main view (SamplesView) I'm displaying a List of Samples, and I want titles be editable directly from the list. For that, I've made a sub-view (SampleRowView) with a TextField, and I'm displaying this sub-view in the List using ForEach.
It works and looks okayish. Though, I can edit the title only if I click directly on the TextField's text (point 1 on the screenshot). If I click on the "empty" part of the TextField (f.e. point 2) it does not respond. I thought that the shape of the TextField is limited somehow by the length of its text, but as visible on the screenshot, TextField occupies the whole row.
Appreciate any help and ideas about how to make the TextField respond to click on its any point, not only on the text.
// "Sample" is a CoreData entity
public class Sample: NSManagedObject {
//...
#NSManaged public var title: String
}
// This is the main view
struct SamplesView: View {
#FetchRequest(...)
var samples: FetchedResults<Sample>
var body: some View {
VStack {
List {
ForEach(samples) { sample in
SampleRowView(sample: sample)
}
.onDelete(perform: deleteSample)
}
}
}
}
// List rows with editable Sample's title
struct SampleRowView: View {
#ObservedObject var sample: Sample
var body: some View {
TextField("", text: $sample.title)
}
}
Update:
The problem is the same even on the fresh project. Also, if I change TextField with TextEditor the behavior is kinda expected.
Digging a bit more into it:
TextField inside a List in SwiftUI on macOS: Editing not working well
Editable TextField in SwiftUI List
SwiftUI make ForEach List row properly clickable for edition in EditMode
I've found that it seems to be a bug in SwiftUI, and for now the only solution is to somehow replace the List with ScrollView with custom item moving and deletion. This is sad.
import SwiftUI
struct Sample: Identifiable {
let id: Int
var title: String
init(id: Int) {
self.id = id
self.title = "Sample \(id)"
}
}
struct TestView: View {
#State var samples = [Sample(id: 1), Sample(id: 2)]
var body: some View {
List {
ForEach($samples) { $sample in
TextField("", text: $sample.title) // .textFieldStyle(.squareBorder) -- doesn't help
// TextEditor(text: $sample.title) // This works as expected
}
}
}
}
#main
struct SampleApp: App {
var body: some Scene {
WindowGroup {
TestView()
}
}
}
I'm using XCode Version 13.2.1, Swift 5, MacOS deployment target 11.6.
You could try to add
.contentShape(Rectangle())
to your View element.
I use it along with Text()-Instances which allows me to accept clicks not only on the written part of the View element, but everywhere within its bounds.

SwiftUI Navigation popping back when modifying list binding property in a pushed view

When I update a binding property from an array in a pushed view 2+ layers down, the navigation pops back instantly after a change to the property.
Xcode 13.3 beta, iOS 15.
I created a simple demo and code is below.
Shopping Lists
List Edit
List section Edit
Updating the list title (one view deep) is fine, navigation stack stays same, and changes are published if I return. But when adjusting a section title (two deep) the navigation pops back as soon as I make a single change to the property.
I have a feeling I'm missing basic fundamentals here, and I have a feeling it must be related to the lists id? but I'm struggling to figure it out or work around it.
GIF
Code:
Models:
struct ShoppingList {
let id: String = UUID().uuidString
var title: String
var sections: [ShoppingListSection]
}
struct ShoppingListSection {
let id: String = UUID().uuidString
var title: String
}
View Model:
final class ShoppingListsViewModel: ObservableObject {
#Published var shoppingLists: [ShoppingList] = [
.init(
title: "Shopping List 01",
sections: [
.init(title: "Fresh food")
]
)
]
}
Content View:
struct ContentView: View {
var body: some View {
NavigationView {
ShoppingListsView()
}
}
}
ShoppingListsView
struct ShoppingListsView: View {
#StateObject private var viewModel = ShoppingListsViewModel()
var body: some View {
List($viewModel.shoppingLists, id: \.id) { $shoppingList in
NavigationLink(destination: ShoppingListEditView(shoppingList: $shoppingList)) {
Text(shoppingList.title)
}
}
.navigationBarTitle("Shopping Lists")
}
}
ShoppingListEditView
struct ShoppingListEditView: View {
#Binding var shoppingList: ShoppingList
var body: some View {
Form {
Section(header: Text("Title")) {
TextField("Title", text: $shoppingList.title)
}
Section(header: Text("Sections")) {
List($shoppingList.sections, id: \.id) { $section in
NavigationLink(destination: ShoppingListSectionEditView(section: $section)) {
Text(section.title)
}
}
}
}
.navigationBarTitle("Edit list")
}
}
ShoppingListSectionEditView
struct ShoppingListSectionEditView: View {
#Binding var section: ShoppingListSection
var body: some View {
Form {
Section(header: Text("Title")) {
TextField("title", text: $section.title)
}
}
.navigationBarTitle("Edit section")
}
}
try this, works for me:
struct ContentView: View {
var body: some View {
NavigationView {
ShoppingListsView()
}.navigationViewStyle(.stack) // <--- here
}
}
Try to make you object confirm to Identifiable and return value which unique and stable, for your case is ShoppingList.
Detail view seems will pop when object id changed.
The reason your stack is popping back to the root ShoppingListsView is that the change in the list is published and the root ShoppingListsView is registered to listen for updates to the #StateObject.
Therefore, any change to the list is listened to by ShoppingListsView, causing that view to be re-rendered and for all new views on the stack to be popped in order to render the root ShoppingListsView, which is listening for updates on the #StateObject.
The solution to this is to change the #StateObject to #EnvironmentObject
Please refactor your code to change ShoppingListsViewModel to use an #EnvironmentObject wrapper instead of a #StateObject wrapper
You may pass the environment object in to all your child views and also add a boolean #Published flag to track any updates to the data.
Then your ShoppingListView would look as below
struct ShoppingListsView: View {
#EnvironmentObject var viewModel = ShoppingListsViewModel()
var body: some View {
List($viewModel.shoppingLists, id: \.id) { $shoppingList in
NavigationLink(destination: ShoppingListEditView(shoppingList: $shoppingList)) {
Text(shoppingList.title)
}
}
.navigationBarTitle("Shopping Lists")
}
}
Don't forget to pass the viewModel in to all your child views.
That should fix your problem.

SwiftUI NavigationLink

I'm working on a SwiftUI practice app and I ran into an issue with the NavigationView/NavigationLink. I am currently using the Metropolitan Museum of Art API and I wanted to make a list of departments that segues to another list of objects in that department, then that list segues to the object's information. Currently the NavigationView/NavigationLink setup I have is creating multiple NavigationViews and is resulting in multiple back buttons/navigation bars. Is there a way to have the new NavigationView replace the old one or have them work in line with one another? The only way I know how to create a segue in SwiftUI is through a NavigationView/NavigationLink but creating it twice seems to be the wrong way to go about things. I have a screen shot of the current state of my app.
App Image
This is my code at the moment.
struct ContentView: View {
#ObservedObject var model = DepartmentListViewModel()
var body: some View {
NavigationView {
List {
ForEach(model.departments, id: \.self) { department in
NavigationLink(destination: DetailView(viewModel: DetailListViewModel(selectedDepartment: department))) {
Text(department.displayName)
}
}
}
.navigationBarTitle("Departments")
}
}
}
struct DetailView: View {
#ObservedObject var viewModel: DetailListViewModel
init(viewModel: DetailListViewModel) {
self.viewModel = viewModel
}
var body: some View {
NavigationView {
List {
ForEach(viewModel.objects, id: \.self) { object in
NavigationLink(destination: ObjectView(viewModel: ObjectListViewModel(selectedObject: object))) {
Text(String(object))
}
}
}
.navigationBarTitle("ObjectIDs")
}
}
}
You don't need NavigationView in your DetailView anymore, the first one handle it

SwiftUI: Navigate from Sheet to a new View

How can I push a new View on the navigation stack from within a Sheet. I want to display a list of Lessons. When tabbing on one of the lessons, a sheet should open showing details about the lesson. From within the Sheet one should be able to start the lesson in a new fullscreen view.
import SwiftUI
struct ContentView: View {
var lessons = [Lesson(id:"1"), Lesson(id:"2"), Lesson(id:"3"), Lesson(id:"4"), Lesson(id:"5"), Lesson(id:"6"), Lesson(id:"7"), Lesson(id:"8"), Lesson(id:"9")]
var body: some View {
NavigationView(){
Form{
List(lessons){ lesson in
LessonButton(lesson: lesson)
}
}
}
}
}
struct LessonButton:View{
#State var showSheet = false
var lesson:Lesson
var body: some View {
Button(action:{self.showSheet = true}){
Text(lesson.name)
}.sheet(isPresented:$showSheet){
NavigationLink(destination: Text("reached")){
Text("start")
}
}
}
}
struct Lesson: Identifiable{
var id:String
var name: String{
"Lesson \(self.id)"
}
}
However the NavigationLink is not working. I guess, this is because the Sheet is not a ChildView of Content View. That's probably why it does not work. But how can it be achieved?
A bit late, but this question came up while solving this. Your sheet acts like its own view controller stack. You can't navigate the parent through the sheet overlay, nor should you. It does seem like you're asking what I was looking for, which is to emulate other apple apps that navigate in sheets. You simply need an additional NavigationView within your sheet. This will give you a navigation stack to push other sheet styled views to the navigation controller within your first sheet.
(SwiftUI beginner, verbiage is likely wrong)
import SwiftUI
struct NavigateFromSheet: View {
var lessons = [Lesson(id:"1"), Lesson(id:"2"), Lesson(id:"3"), Lesson(id:"4"), Lesson(id:"5"), Lesson(id:"6"), Lesson(id:"7"), Lesson(id:"8"), Lesson(id:"9")]
var body: some View {
NavigationView(){
Form {
List(lessons){ lesson in
LessonButton(lesson: lesson)
}
}
}
}
}
struct LessonButton:View{
#State var showSheet = false
var lesson:Lesson
var body: some View {
Button(action:{self.showSheet = true}){
Text(lesson.name)
}.sheet(isPresented: $showSheet){
NavigationView {
VStack {
Text("My First Sheet")
NavigationLink(destination: Text("reached")){
Text("My Second Sheet")
}
}
}
}
}
}
struct Lesson: Identifiable{
var id:String
var name: String{
"Lesson \(self.id)"
}
}
struct NavigateFromSheet_Previews: PreviewProvider {
static var previews: some View {
NavigateFromSheet()
}
}
Sheet is modal view mode, you can enter in it and return back from it.
Actually I can't understand why do you need a sheet in described scenario. As you described it is expected:
List -> Details -> Lesson,
so use consequently two navigation links, one in List, one in Details. This is a native Apple design for NavigationView/NavigationLink usage - navigation from view to view.

Present a View Non-Modally

I am creating a sign in page for my app and would like to present the home screen in a way that the user can not go back. In Swift UI how do I present it so the new view does not present in a card like style? I know this presenting style is now default for iOS 13.
This is what I already have.
import SwiftUI
struct Test : View {
var body: some View {
PresentationButton(Text("Click to show"), destination: Extra() )
}
}
I would like the view to present full screen.
Use a NavigationView with a NavigationButton and hide the destination view's navigation bar's back button.
For example:
struct ContentView : View {
let destinationView = Text("Destination")
.navigationBarItem(title: Text("Destination View"), titleDisplayMode: .automatic, hidesBackButton: true)
var body: some View {
NavigationView {
NavigationButton(destination: destinationView) {
Text("Tap Here")
}
}
}
}
You can also disable the destination view's navigation bar altogether by doing let destinationView = Text("Destination").navigationBarHidden(true).