Instafilter: Wrap up

Paul Hudson    @twostraws    November 28th 2019

We covered a lot of ground in this tutorial, and we’ll be coming back to a lot of it in the very next project – working with UIKit isn’t a “nice to have” for most apps, so it’s best you get used to it and start building up your library of functionality wrappers.

Still, we also learned some great SwiftUI stuff, including action sheets and custom bindings, both of which are super common and will continue to be useful for years to come.

And there’s Core Image. This is another one Apple’s extremely powerful frameworks that never quite made the smooth leap to Swift – you need to know it’s quirks if you want to make the most of it. Still, you’re through the worst of it now, so hopefully you can try using it in your own code!

Review what you learned

Anyone can sit through a tutorial, but it takes actual work to remember what was taught. It’s my job to make sure you take as much from these tutorials as possible, so I’ve 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 what’s going on.

1. Try making the Save button show an error if there was no image in the image view.
2. Make the Change Filter button change its title to show the name of the currently selected filter.
3. Experiment with having more than one slider, to control each of the input keys you care about. For example, you might have one for radius and one for intensity.