iOS Dev Interview Prep - Take Home Project - UIKit - Programmatic UI - FULL COURSE

Introduction

This tutorial is designed to guide you through a mock take-home project typical in the iOS developer job interview process. By following these steps, you will learn how to build a complete app that fetches followers from a GitHub username, utilizing programmatic UI and no third-party libraries. This project is updated for iOS 15, 16, and 17, making it relevant for current development practices.

Step 1: Understand the Project Brief

• Familiarize yourself with the goals of the project:
  • Fetch a list of followers from a GitHub username.
  • Allow users to set and persist a favorite GitHub user.
• Review the GitHub API documentation for fetching followers: GitHub API Documentation.

Step 2: Set Up Your Xcode Project

• Create a new Xcode project.
• Delete the default storyboard:
  • Open the project settings.
  • Under "Deployment Info," uncheck "Main Interface."
• Set up the initial programmatic UI in AppDelegate.swift or SceneDelegate.swift depending on your project configuration.

Step 3: App Navigation Setup

• Implement a UITabBarController and UINavigationController for app navigation:
  • Create a TabBarController to manage different sections of your app.
  • Embed view controllers within a NavigationController as needed.

Step 4: Design Custom UI Components

• Create custom UIButton and UITextField classes to enhance UI:
  • Subclass UIButton and customize appearance.
  • Subclass UITextField for consistent styling across the app.

Step 5: Build the Search Screen UI

• Design a user interface for the search functionality:
  • Include a search bar for users to input GitHub usernames.
  • Display results in a list format.

Step 6: Pass Data Between Views

• Use delegation or closures to pass data from one view controller to another:
  • Define protocols for communication.
  • Implement delegate methods to handle data transfer.

Step 7: Create Network Calls

• Plan your network call to fetch followers:
  • Use URLSession for making HTTP requests.
  • Handle JSON parsing to convert API responses into model objects.

func fetchFollowers(for username: String) {
    let url = URL(string: "https://api.github.com/users/\(username)/followers")!
    let task = URLSession.shared.dataTask(with: url) { data, response, error in
        // Handle response
    }
    task.resume()
}

Step 8: Implement UICollectionView for Displaying Followers

• Set up a UICollectionView to display follower information:
  • Create a custom cell class for follower representation.
  • Implement UICollectionViewDiffableDataSource for efficient data handling.

Step 9: Handle Pagination

• Implement pagination to manage large sets of follower data:
  • Load additional followers as the user scrolls down.
  • Keep track of the current page and update requests accordingly.

Step 10: Optimize for Performance

• Refactor your code for performance enhancements:
  • Use ARC (Automatic Reference Counting) to manage memory efficiently.
  • Implement caching for avatar images to reduce network calls.

Step 11: Implement Persistence

• Set up data persistence to save favorite users:
  • Use UserDefaults or Core Data to store user choices.
  • Create a simple PersistenceManager to handle save and retrieve operations.

Step 12: Finalize and Test Your App

• Conduct thorough testing of your application to ensure all features work as intended:
  • Test various scenarios, such as empty states and error handling.
  • Optimize UI elements for different screen sizes.

Conclusion

By completing this tutorial, you have built a fully functional iOS app utilizing programmatic UI and learned essential skills for iOS development. This experience will not only prepare you for technical interviews but also enhance your overall development capabilities. Next, consider exploring advanced topics such as SwiftUI or further optimizing your app's architecture.