Day 52
Day 52 ๊ด๋ จ
Project 10, part 4
Every new project we work on here introduces new concepts to you in isolation and then again in the context of a real app, with the goal being that showing you the same thing twice in different circumstances helps it sink deeper into your long-term memory.
But today, with our app finished, itโs time for another important part of the long-term process: a test of what you remember, and some challenges to help push you further. Like it or not, this step matters โ as the astronaut John Young once said, โthe greatest enemy of progress is the illusion of knowledge.โ
Trust me on this: knowing you understand something is way better than thinking you understand it. This is why I keep drilling the essentials into you: I want you to get so bored with Form that you could almost write this course yourself. I want you to see Codable and know exactly what it means and how it works behind the scenes, and never to think to yourself that itโs somehow magic.
All these foundations weโre building here are going to last you for years, and it means everything you build on top โ everything you learn or create in the future โ isnโt built on top of half understanding something you read once, but is instead something you can have real, lasting confidence about.
Today you should work through the wrap up chapter for project 10, complete its review, then work through all three of its challenges.
Cupcake Corner: Wrap up
Cupcake Corner: Wrap up
Hopefully this project has shown you how to take the skills you know โ SwiftUIโs forms, pickers, steppers, and navigation โ and build them into an app that sends all the userโs data off to a server and processes the response.
You might not realize this yet, but the skills you learned in this project are the most important skills for the vast majority of iOS developers: take user data, send it to a server, and process the response probably accounts for half the non-trivial apps in existence. Yes, what data gets sent and how itโs used to update the UI varies massively, but the concepts are identical.
Review what you learned
Anyone can sit through a tutorial, but it takes actual work to remember what was taught. Itโs my job to make sure you take as much from these tutorials as possible, so Iโve prepared a short review to help you check your learning.
Click here to review what you learned in this project.
Challenge
One of the best ways to learn is to write your own code as often as possible, so here are three ways you should try extending this app to make sure you fully understand whatโs going on.
- Our address fields are currently considered valid if they contain anything, even if itโs just only whitespace. Improve the validation to make sure a string of pure whitespace is invalid.
- If our call to
placeOrder()fails โ for example if there is no internet connection โ show an informative alert for the user. To test this, try commenting out therequest.httpMethod = "POST"line in your code, which should force the request to fail. - For a more challenging task, try updating the
Orderclass so it saves data such as the user's delivery address toUserDefaults. This takes a little thinking, because@AppStoragewon't work here, and you'll find getters and settings cause problems withCodablesupport. Can you find a middle ground?
Cupcake Corner: Wrap up - Additional
