Create an iOS Custom Keyboard extension

Given that the custom keyboard extension is the heart of our application, we'd like to see you create one of your own!

Goal:

Complete the custom keyboard extension that's started in this repo. Use the provided endpoint (see Requirements below) to load content from an API and render it in the keyboard UI (see example layout at the bottom of this page).

Requirements

• All of the UI work should be done in SwiftUI. I already setup the initial rendering of our root SwiftUI view in RootView.swift. You should be able to implement a typical SwifUI application from there.
  • Note KeyboardViewController acts as the lifecycle controller for the entire keyboard. Somewhat like the AppDelegate for the extension.
• You can send a GET request to https://frontend-coding-challenge-api.herokuapp.com/getContent to fetch the content.
  • Remember to display a loading state while the content is being fetched.
  • The API will randomly (about 1/5 times) return an error with status code 500 and json data { error: 'Random Error' }. Make sure you handle this.
• Tapping each button should output its content to the text input (see resources below).
  • When you tap the first time, the app should output the first (index == 0) piece of attached content. When you tap the second time, it should output the second piece, etc
  • When you've reached the last piece of content, tapping again should cycle back to the beginning
  • TIP: inspect the data coming back from the api to figure out the structure of the extra content.
• Match Apple's keyboard styling as best you can.
• Make sure to include a button to exit your custom keyboard and take the user back to the default keyboard

Additional (please implement at least 1)

• Long-press delete functionality that mimics Apple's
• Long-press on a button show's a popup list with all of the content options.
  • Selecting one should output it to the text input
• Use some sort of frontend caching/storage to avoid showing a loading state every time the user toggles in and out of the keyboard.
• Other fun or useful UI improvements. This is up to you! Some examples:
  • A moving progress bar on each button that shows how far the user has progressed in the content
  • Animate the text moving from the button up to the text input
  • Transitions between different states (loading, error, rendering the content)
  • Dark mode

Instructions for running the keyboard on device or simulator

1. Open keysCustomKeyboardChallenge.xcodeproj in Xcode
2. Select target keyboard from the target dropdown list and a simulator or your own device to run it on.

3. You will see a popup with options for a "host" application where you can run the keyboard extension. You can choose any application to run the keyboard, but messages is probably the most relevant

4. You will need to turn on the keyboard in Settings. In the simulator/device navigate to Settings -> General -> Keyboard -> Keyboards -> Add New Keyboard -> keysCustomKeyboardChallenge. Then navigate back to Messages and you should be able to switch to the keyboard using the globe button. See demo video here

Resources

• Apple's iOS Custom keyboard getting started guide (the initial setup is already completed)
• How to output text from an iOS Custom Keyboard

Example layout: