Share Sheet UIActivityViewController within SwiftUI

Hoye Lam | 林浩意 — Tue, 26 Jan 2021 19:16:27 +0000

With Growrilla 1.5.0 released, users can now share their progress more easily.

Thus I also want to share how I did it.

First, we have the make the UIActivityViewController usable with SwiftUI. Thus we are going to wrap it around a UIViewControllerRepresentable.

struct ActivityViewController: UIViewControllerRepresentable {

    @Binding var activityItems: [Any]
    var excludedActivityTypes: [UIActivity.ActivityType]? = nil

    func makeUIViewController(context: UIViewControllerRepresentableContext<ActivityViewController>) -> UIActivityViewController {
        let controller = UIActivityViewController(activityItems: activityItems,
                                                  applicationActivities: nil)

        controller.excludedActivityTypes = excludedActivityTypes

        return controller
    }

    func updateUIViewController(_ uiViewController: UIActivityViewController, context: UIViewControllerRepresentableContext<ActivityViewController>) {}
}

Then we create a custom ViewModifer to more easily views more easily implement the sharing feature.

struct ShareSheetModifer: ViewModifier {
    @State private var showShareSheet: Bool = false
    @State var shareSheetItems: [Any] = []

    func body(content: Content) -> some View {
        content
            .contextMenu {
                Button(action: {
                    self.showShareSheet.toggle()
                }) {
                    Text("Share")
                    Image(systemName: "square.and.arrow.up")
                }
            }
            .sheet(isPresented: $showShareSheet, content: {
                ActivityViewController(activityItems: self.$shareSheetItems)
            })
    }
}

Within my example, I’m creating this sharing feature with a context menu, but you can easily change it to being a double tap for example with onTapGesture.

Then to use it, add the modifier to your SwiftUI Element like the following with the items that you want to share.

Text("Hello, world!")
            .padding()
            .modifier(ShareSheetModifer(shareSheetItems: ["Hello, world!"]))

While this is already okay to use, I personally don’t like to write my modifiers in this way. Thus, you can use the following extension on View.

extension View {
    func shareSheet(items: [Any], excludedActivityTypes: [UIActivity.ActivityType]? = nil) -> some View {
        self.modifier(ShareSheetModifer(shareSheetItems: items))
    }
}

Then you use it the following way:

Text("Hello, world!")
            .padding()
            .shareSheet(items: ["Hello world!"])

If you want to exclude activity types like for example posting the items to Facebook, you use the it the following way:

Text("Hello, world!")
                .padding()
                .shareSheet(items: ["Hello world!"], excludedActivityTypes: [.postToFacebook])

Hope you enjoyed it!

For the full code snippet:
Share Sheet UIActivityViewController within SwiftUI · GitHub

Summing up numeric properties of objects in an array in Swift

Hoye Lam | 林浩意 — Mon, 18 Jan 2021 13:53:57 +0000

You can read this blogpost also here.

You may want to sum up properties from an object. For example, you may retrieve log data from your analytics web server.

A struct could be the following:

struct ActionLog: Codable {
    var actionId: Int
    var actionPerformed: Int
    var creationDate: Date
}

This struct could for example contain a log of a certain action taken within a software product.

actionId = the ID of a certain action (i.e button press, purchase, authentication)
actionPerformed = the number of times this action was performed during a log

With these logs, you may have as aim to calculate the total amount of actions performed of a certain action. How do you this?

First, let’s break down the requirement into smaller pieces.

Filter all the actions based on the actionId
Get all the actionPerformed Integer based on the actionId
Sum all the retrieved actionPerformed Integers.

Now that we know what we want to do, let’s code it as well.

// 1. Filter step
let desiredActionId = 1
let filteredLogs = logs.filter( {$0.actionId == desiredActionId} )

// 2. Get the `actionPerformed` integers
let numbers = filteredLogs.map( {$0.actionPerformed })

// 3. Sum all the integers up
let totalAmount = numbers.reduce(0, +)

Or if you want much shorter.

let totalAmount = logs
    .filter( {$0.actionId == desiredActionId} ) // Step 1
    .map( {$0.actionPerformed }) // Step 2
    .reduce(0, +) // Step 3

This a solution on how to sum up numeric properties of an object in an array.

You can test the code with a here:

struct ActionLog: Codable {
    var actionId: Int
    var actionPerformed: Int
    var creationDate: Date
}

var logs: [ActionLog] = []

for _ in 0..<100 {
    logs.append(.init(actionId: 1,
                      actionPerformed: 1,
                      creationDate: Date()))

    logs.append(.init(actionId: 2,
                      actionPerformed: 2,
                      creationDate: Date()))
}

// 1. Filter step
let desiredActionId = 1
let filteredLogs = logs.filter( {$0.actionId == desiredActionId} )

// 2. Get the `actionPerformed` integers
let numbers = filteredLogs.map( {$0.actionPerformed })

// 3. Sum all the integers
let total = numbers.reduce(0, +)

print("Total amount of actions performed of action 1: \¡(total) times")

// shorter
let totalShort = logs
    .filter( {$0.actionId == desiredActionId} ) // Step 1
    .map( {$0.actionPerformed }) // Step 2
    .reduce(0, +) // Step 3

print("Total amount of actions performed of action 1: \(totalShort) times")

DEV Community: Hoye Lam | 林浩意

Share Sheet UIActivityViewController within SwiftUI

Summing up numeric properties of objects in an array in Swift