@Appstorage in SwiftUI

Appstorage is a property wrapper for getting stored values from UserDefaults in SwiftUI. We use @Appstorage too reload our body view property whenever the value changes of our UserDefaults. This keeps our view up to date with the data that we have stored. Let’s take a look at an example on how we can use @Appstorage in our SwiftUI project.

import SwiftUI

struct ContentView: View {
    @AppStorage("isCookieTime") var isCookieTime = false
    
    var body: some View {
            Toggle("Cookie time", isOn: $isCookieTime)
        .padding()
    }
}

In the example above we have a Toggle view for “Cookie time” πŸͺ. We use our @AppStorage property to watch our isCookieTime variable. If the value changes it is then stored in our UserDefaults. Now our toggle will show the stored value depending on the @AppStorage.

A example of where I use @AppStorage is for storing things like a users settings options in a settings screen of an app. I hope this helps explain how to use @AppStorage in SwiftUI.

Thanks for reading and happy coding.

How to Make a Code Snippet in Xcode

Code snippets are shortcuts to blocks of boilerplate code that we use most often when programming. Xcode allows us to add custom snippets to the many pre-existing snippets that Apple provides. Let’s see how we can make a code snippet out of the following code below.

DispatchQueue.main.async {
                    
                }

You might be familiar with the example code above. This block of code is used to make sure things like network calls are made on the main thread and not on a background thread. Let’s make a code snippet of this so we don’t have to type the whole thing out every time we want to use it.

If we highlight the code and then right click (⌘ + click) you will see an option to “Create Code Snippet”.

Once we click on “Create Code Snippet” a window will popup and prompt us to customize our code snippet.

First we will name our snippet “Dispatch Main Queue” (Feel free to name it whatever you want πŸ˜„). Now we will leave everything else the same except the “Completion” section. In the “Completion” textfield we will type in “dpm”.

What this does is every time we type “dpm” Xcode will prompt us in the autocompletion to see if we want to use our code snippet! So from now on anytime we want to put something on the main thread all we have to do is type “dpm” and we get our code snippet we just created.

Just like that we have made a code snippet and saved ourselves time by never having to type out all that code ever again! Feel free to make code snippets of any block of code your tired of typing out! Embrace your laziness!

Thanks for reading and I hope this helps your coding productivity.

Happy coding!

Texas Tribune Nerds - What I Learned at The Texas Tribune

How to Make a Tab Bar View in SwiftUI

In this post we are going to take a look at how we can add a tab bar view to our SwiftUI app. Tab bar views are used to display a view when the tab item is selected. For this example we will simply have two tab views that will show a text view with a different background color. Let’s start by creating our example views that we will assign to our tab bar.

import SwiftUI
struct FirstView: View {
    var body: some View {
        ZStack {
            Color(.green)
            Text("First View")
                .font(.title)
        }.ignoresSafeArea()
    }
}
struct SecondView: View {
    var body: some View {
        ZStack {
            Color(.blue)
            Text("Second View")
                .font(.title)
                .foregroundColor(.white)
        }.ignoresSafeArea()
    }
}

As you can see we have created two views with just a text view and a color for the background. Now that we have our views setup we can go to our ContentView.swift file and make our tab bar view.

import SwiftUI
struct ContentView: View {
    var body: some View {
        TabView {
            FirstView()
                .tabItem {
                    Image(systemName: "1.circle.fill")
                    Text("First View")
                }
        
            SecondView()
                .tabItem {
                    Image(systemName: "2.circle.fill")
                    Text("Second View")
                }
        }
    }
}

As you can see in the example above all we needed to do was make a TabView and initialize our two views as a .tabItem. Inside of our .tabItem we added an image and the title to be displayed on our tab. Now if we run our application we should see our app look like the images below.

I hope this helps you on your next SwiftUI project.

Thanks for reading and happy coding!

How to Fetch JSON Data from APIs in SwiftUI

In this post we are going to take a look at how we can get JSON data from an API and show it in a list view in SwiftUI. Let’s jump right in a get started by creating a new SwiftUI project.

In this project we are going to be using the JSONPlaceholder API. JSONPlaceholder is a free to use fake REST API for testing and prototyping.

We will be fetching our data from the https://jsonplaceholder.typicode.com/posts/1/comments URL.

Now in our Xcode project we will create a model file and name it Comments. This will be our model for the data we are going to want to show in our list view.

import SwiftUI

struct Comments: Codable, Identifiable {
    let id = UUID()
    let name: String
    let email: String
    let body: String
    
}

In the code above we made a simple struct that conforms to the Codable and Identifiable protocols. Codable is used for decoding and encoding the JSON data we get from our API call. Identifiable is used to help us make a unique identifier for our Comments object so our app can keep track of it. In our example it helps us to keep track of our comments and display them in the right order for our list view. We also have added the name, email, and body properties that will be set to the JSON data we get back from our API call.

Next we will add a new file where we will create the call to our API to get our JSON data. Let’s start by creating a new file and naming it commentViewModel. Then we will add the following code to our commentViewModel file.

import Foundation

class apiCall {
    func getUserComments(completion:@escaping ([Comments]) -> ()) {
        guard let url = URL(string: "https://jsonplaceholder.typicode.com/posts/1/comments") else { return }
        
        URLSession.shared.dataTask(with: url) { (data, _, _) in
            let comments = try! JSONDecoder().decode([Comments].self, from: data!)
            print(comments)
            
            DispatchQueue.main.async {
                completion(comments)
            }
        }
        .resume()
    }
}

Above all we did was create a class called apiCall and added a function called getUserComments(). In our getUserComments() function we first make a guard let statement on our url variable. This is to check to make sure we have a valid URL otherwise the function will stop there and not execute the rest of the code.

Next we use URLSession to make our call to get the data from the URL. Inside of our URLSession closure we create a new variable called comments and we assign the decoded JSON to our variable. Then we use DispatchQueue to make sure we are running this API call on the main thread and not a background thread of our app. On completion of retrieving our data we then assigns the data to our comments variable. Lastly we can’t forget the .resume() function at the end of your URLSession curly brace. If you forget this the function will never run the API call to the URL.

Now that we have our view model setup lets go into ContentView file and add the following code to our file.

import SwiftUI

struct ContentView: View {
    //1.
    @State var comments = [Comments]()
    
    var body: some View {
        NavigationView {
            //3.
            List(comments) { comment in
                VStack(alignment: .leading) {
                    Text(comment.name)
                        .font(.title)
                        .fontWeight(.bold)
                    Text(comment.email)
                        .font(.subheadline)
                        .fontWeight(.bold)
                    Text(comment.body)
                        .font(.body)
                }
                
            }
            //2.
            .onAppear() {
                apiCall().getUserComments { (comments) in
                    self.comments = comments
                }
            }.navigationTitle("Comments")
        }
    }
}
  1. First we created a @State variable that takes in an array of our Comments model.
  2. Next we added the .onAppear() function. This is were we make our call to our API to get our data and then set it to the comments variable we just created.
  3. Then in our list view we pass in the data that we have in our Comments array

Now we can go and run our app. We should see something like the image below.

Thats all we need to fetch and show JSON data in SwiftUI. Thanks for reading!

Happy Coding!

data numbers GIF

How to Make a Phone Call using SwiftUI

Making a phone call from a SwiftUI app is easy and only takes a few lines of code to implement. All we need to do is setup a button that will open the phone app and make a phone call with a phone number we pass in.

Let’s look at some code below to see what we need to implement this.


struct ContentView: View {

    var phoneNumber = "718-555-5555"

    var body: some View {
        VStack {
            Button(action: {
                let phone = "tel://"
                let phoneNumberformatted = phone + phoneNumber
                guard let url = URL(string: phoneNumberformatted) else { return }
                UIApplication.shared.open(url)
               }) {
               Text(phoneNumber)
                .foregroundColor(.blue)
            }
        }
    }
}

In the example above we first create a string variable with the phone number we would like to use. Next we create a button and within the action of our button we format the phone number to our URL. The “tel://” is the url needed to tell our device to open the phone app and make a call. (We can use the same code above to open other apps on our device. For example if we wanted to open the mail app we just need to replace the url with messages:// instead of tel://)

Next we have a guard let statement to check to see if we have a formatted phone number. Then we use UIApplication to open the phone app and make a call using the url with the phone number we passed in. Lastly we set our button label to show the phone number we want to call.

(Side note: We will need to run this on a device to test because the simulator can not make phone calls.)

That is all that we need to make a phone call from our SwiftUI app. Hope this helps you on your next SwiftUI project!

Thanks for reading!

β˜ŽοΈπŸ“±πŸ€³Happy coding β˜ŽοΈπŸ“±πŸ€³

What’s the Difference between @ObservedObject and @StateObject

@StateObject and @ObservedObject are very similar in that they both keep track of an objects state. The difference is @StateObject is owned by the view it was created in where as @ObservedObject is owned by another view.

An example of when to use @ObservedObject is to keep track of external classes so the view can be updated when a change occurs. We would want to use an @ObservedObject for something like fetching new data from an API or a database.

We want to use @StateObject when we want the view to keep track of its own objects state. A example of how we would use @StateObject is if we had something like a number counter in a view and we wanted to keep track of the count as the numbers changed.

I hope this helps you better understand the difference between when to use @ObservedObject and @StateObject.

For a deeper dive into @StateObject vs @ObservedObject checkout these great articles by Donny Wals and Swapnanil Dhol.

Thanks for reading and happy coding πŸ‘¨πŸ»β€πŸ’»πŸ‘¨πŸ»β€πŸ’»πŸ‘¨πŸ»β€πŸ’»

How to Use Link to Open Webpages in SwiftUI

SwiftUI makes opening a URL with your default web browser super easy with the Link view. All you need to do is give it a title and a destination URL. Let us take a look at the example below.

import SwiftUI

struct ContentView: View {
    var body: some View {
        Link("Swift Tom!", destination: URL(string: "https://www.swifttom.com/")!)
        
    }
}

As you can see in our example we are added a title of “Swift Tom!” and our destination URL swifttom.com. If we go and run this code in our simulator we will see our Link button that when it is tapped will bring us to my swifttom.com webpage.

Hope you enjoyed this quick look at how we can use Link views to our SwiftUI project.

For more on how to use Link views we can check out Apple’s Documentation here.

πŸ”—πŸ”—πŸ”— Happy Coding! πŸ”—πŸ”—πŸ”—

How to Blur a View in SwiftUI

SwiftUI makes it easy to add a blur effect to any view. All we need to do is add the .blur() modifier to our view. Let’s see how we can apply this by looking at the example below.

 import SwiftUI
import PlaygroundSupport
struct ContentView: View {
    var body: some View {
        ZStack {
            Color.green.edgesIgnoringSafeArea(.all)
            Text("Hello Tom")
        }
    }
}
PlaygroundPage.current.setLiveView(ContentView()) 

As you can see in the example we have a ZStack with a green background and a text view. If we want to add a blur effect to our text view all we need to do is add the .blur() modifier to it.

 import SwiftUI
import PlaygroundSupport
struct ContentView: View {
    var body: some View {
        ZStack {
            Color.green.edgesIgnoringSafeArea(.all)
            Text("Hello Tom")
                .blur(radius: 1.5)
        }
    }
}
PlaygroundPage.current.setLiveView(ContentView()) 

As you can see above we added the blur effect with a 1.5 radius to our β€œHello Tom” text view. It is good to know that the higher the radius the more blurry the view will appear.

Thanks for reading and happy coding!

How to Use SF Symbols in a SwiftUI project

SF Symbols are set of over 2,000 symbols created by Apple for developers to use in there apps. SF Symbols are dynamic. This means that they will automatically align with the size and weight of text in our app. We can use these symbols for almost anything but they are most commonly used in toolbars, menus, and navigation bars.

We can use SF Symbols in our project by using the Image(systemName:) image view. In the system name parameter we will add the string of the SF Symbol we want to use.

Image(systemName: β€œcloud.sun.fill”)

As you can see in the example above we added the β€œcloud.sun.fill” SF Symbol to our image view.

We can also customize SF Symbols. If we want to change something like the color of our SF Symbol all we need to do is change the .foregroundColor(). We can also change the size of our symbol by changing the .font size.

Image(systemName: “cloud.heavyrain.fill”)
.foregroundColor(.green)
.font(.title)

That was a quick look at how we can add SF Symbols to our SwiftUI projects. For more info checkout Apples Human Interface Guidelines on how you should use SF Symbols in our projects.

Thanks for reading and Happy Coding!

Access Control in Swift

What is Access Controls in Swift? According to the documentation “Access control restricts access to parts of your code from code in other source files and modules. This feature enables you to hide the implementation details of your code, and to specify a preferred interface through which that code can be accessed and used.” We can implement access controlS by adding five different types of modifiers to our code. These modifiers are:

  • Public: Which means anyone can read and write to this property.
  • Internal: This is the default access control for any property we create. This allows us access within the same module.
  • File Private: Like the name says, this modifier allows us to only access this property within the same file.
  • Private: This is the most restrictive. This only allows access within the current enclosing it is being used in.
  • Open: This is the most unrestricted. This property can be accessed from anywhere and other developers can subclass it and/or override it.

If you would like a deeper dive into Access Control check out the Swift Documentation on it.

Thanks for reading and I hope this gives you a better understand of when to use Access Controls in Swift.

Happy Coding!!!