DevFright

Learn How to Create iOS Apps

How to use Apple Intelligence Writing Tools in SwiftUI

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Apple Intelligence launched with iOS 18, and along with that, several tools that can be integrated into your app. These include:

  • Writing Tools
  • Image Playground
  • Genmoji
  • Siri with App Intents

In this tutorial we’ll look at Writing Tools which brings Apple Intelligence to your app. However, to dig deeper into using Writing Tools, you’ll need to use a UIKit view. We’ll look at that in the next tutorial. For now, lets take a look at this VERY brief tutorial as writing tools in SwiftUI is limited to what is baked in.

Apple has added support to some text views, so if you use a TextEditor, for example, you can access writing tools in the normal way and proofread, rewrite, or ask for suggestions for the text you have entered.

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Building a Search Feature in SwiftUI with Array Filtering

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In todays tutorial we’re going to build a very simple list that you can search by using the filter in an Array. The concept is really quite simple, but good to also be aware of for when you might decide to filter on the frontend of the app.

Lets begin by creating a data model that will contain a published array:

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class DataModel: ObservableObject {
    @Published var items: [String] = [
        "Ford", "Vauxhall", "Ferrari", "Lamborghini", "Aston Martin", "Nissan", "Bentley"
    ]
}

The DataModel we use is a class. We conform to the ObservableObject protocol and use the @Published property wrapper. If the array of strings called items is changed, then the @Published property wrapper will notify any view that uses this ObservableObject that a change has happend. The view will then update.

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Building a Widget Extension for iOS – Part 2

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In part 1 of building a widget extension for iOS, we got a very basic Widget built that has some custom UI that shows the beginnings of a pomodoro timer. You can download part 1 below, although if you are new to this tutorial I would recommend starting at Part 1 to follow along each step so you are more familiar with how we got here.

PomodoroDownload

In this part of the tutorial, we’ll look at cleaning up the widget ready for making it work in part 3.

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Creating Custom Modifiers for SwiftUI Views

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When creating views in SwiftUI you will almost certainly use View Modifiers to adjust how a view looks from its font, to border, to colours, and so on. It is not uncommon to have serveral modifiers applied to each item in the view to get the look that you desire.

SwiftUI provides a way to group these modifiers together so that you can apply them as a group. There are a few benefits to this:

First, it cleans up the code in your view because you can have just a single custom modifier applied and keep all of the details encapsulated elsewhere in the code.

Second, it allows you to reuse the same group of modifiers elsewhere in the app so that you can keep your code DRY (don’t repeat yourself). A change in the custom modifier would affect all views that use the custom modifier.

In this tutorial we’ll look at how we can create our own custom modifier and how this can be applied to a view.

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A Look at CompactMap, Map, and when to use them

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A map in Swift provides a way to transform data. There are several types of map, but we’ll just look at compactMap and map today.

Both of these maps are similar in what they accomplish, that is, transform data. Often you will transform elements of a sequence into a new collection with transformed values.

To help clear this up we’ll look at some examples of when this might be useful.

Lets first look at compactMap. This method is used when you have an array that might contain nil values that you want to remove, or perhaps have data that you cannot work with. A compactMap removes the nil values leaving just the values that it can work with.

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let numbers = ["1", "2", "three", "4", "five"]
let convertedNumbers = numbers.compactMap { Int($0) }
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How to Save Text Files with SwiftUI

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Prior to iOS 16, FileManager needed to be used to save text files to the document directory of your app. Although FileManager needs to be used for some tasks, such as getting the contents of a directory, moving, copying, deleting files, and so on, the ability to save a text file is now available in the String class.

Files are stored in the documents directory of your app, which is sandboxed. If you delete your app, then those files will be deleted with it. With this in mind, make sure you understand the implications of this, as you may need to work with FileManager to save documents in iCloud if you want to keep them safe for your user. We’ll cover this in a different tutorial.

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The @AppStorage Property Wrapper

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A long time ago I wrote about NSUserDefaults being a good way to store user preferences within an app. Small amounts of data can be stored such as the current theme as well as other preferences for the app. The data is persisted so that it can be accessed when the app reloads.

Typically you would want to store small amounts of data in there. For larger amounts of data you should look at other means of storage. Data types such as strings, bools, numbers, dates and so on can be stored.

When Swift launched, UserDefaults was became available and enhanced NSUserDefaults by adding slightly better type safety.

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How to Create a Simple To-Do List with Swipe Actions in SwiftUI Using SwiftData

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In a recent tutorial, we looked at the SwiftUI List and included a very brief introduction to Swipe actions. In this tutorial we’ll expand on this in the form of a simple To-Do list app that allows you to swipe to flag or delete tasks. We will also utilise SwiftData hosted in CloudKit so that tasks can be synchronised across devices.

Start by creating a new iOS app by opening Xcode and selecting New > Project.

Select SwiftUI for interface, Swift for language, SwiftData for storage, and make sure Host in CloudKit is selected. Ensure that you select a Team that is a company and not the personal option. SwiftData stored in iCloud requires a development team to be selected.

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A Look at the SwiftUI Preview Macro

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One of the benefits of SwiftUI is the ability to see a preview of the UI you are building in code. As you modifiy views, the preview to the side updates to reflect your changes.

When you first create an app, it comes with a simple preview as follows:

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#Preview {
    ContentView()
}

#Preview is a macro used to preview the view specified, in this case, the ContentView. It is the newer version of PreviewProvider, although that can still be used. An example of that will be shown later in this tutorial.

As you generate views, you’ll quickly run into problems with being unable to preview because ContentView, or another view, might require something to be passed in. In this tutorial, I’ll go through some basics to help you get the most out of the preview macro.

The Preview macro and other view tools allow you to quickly test different varients across different devices, ensuring that your UI works on devices of all sizes and dark/light mode settings.

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SwiftUI List Tutorial

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In an earlier post, we went over what a ForEach loop is used for. In this tutorial, we’ll look at the List.

A List is designed to show a collection of views in a table format, much like how you see your emails, contacts, music and so on. This is similar to the UITableView in concept, but how it is implemented is very different.

If you have read the ForEach loop tutorial, the last example showed how to put four capsules or pills horizontally on the screen. Here is the code we used for this:

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struct TagListView: View {
  
    let discussionPoints = [
        DiscussionPoint(title: "Meeting Agenda", tag: "Important"),
        DiscussionPoint(title: "Budget Review", tag: "Finance"),
        DiscussionPoint(title: "Project Updates", tag: "Development"),
        DiscussionPoint(title: "Team Building", tag: "HR")
    ]
      
    var body: some View {
        HStack {
            ForEach(discussionPoints) { point in
                Text(point.tag)
                    .padding(.horizontal, 12)
                    .padding(.vertical, 6)
                    .background(Capsule().fill(Color.blue.opacity(0.2)))
                    .foregroundColor(.blue)
            }
        }
    }
}
  
struct DiscussionPoint: Identifiable {
    let id = UUID()
    let title: String
    let tag: String
}
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