Top-notch video tutorials for Swift developers

In this episode, we set up our dotfiles to customize aspects of bash, git, vim, and other terminal programs that are core to a good terminal experience.

Managing external beta users can be a bit of a chore, as you have to log into iTunes Connect and add them one by one (or a batch if you have them collected already). If you’re opening your beta to a wider audience, you can save a lot of time by automating it. In this episode we will use Fastlane Boarding to automate adding testers to Testflight.

In this episode we will setup iTerm2, profiles, custom color schemes, and fonts.

In this episode we look at some of the basic system preferences on macOS High Sierra. We set up the Dock, Keyboard shortcuts, and show how to customize key repeat timing outside of the preferences window.

The prefetch APIs for UITableView and UICollectionView are great for preemptively loading pages of data, as we saw in episode 315. However, to take full advantage of this API we should also leverage loading or processing data related to the cells we are about to show. One common example of this is fetching an image before the cell comes on screen. In this episode we will implement this with a handy library called Nuke. The result is quite impressive.

In this episode we cover the dependency inversion principle, which states that high level components should not depend on low level components, but instead they both should depend on abstractions. We will look at two examples of this and leverage dependency injection to decouple classes from concrete dependencies.

Extending our example from episode 309, here we implement automatic tableview paging support by utilizing the UITableViewDatasourcePrefetching protocol. With this protocol, our delegate is notified of upcoming rows the user is about to encounter, and gives us an opportunity to preemptively load data for those rows.

In this episode we examine ISP (the Interface Segregation Principle). This one states that a type should not depend on methods from an interface that it will never use. Often times this means that the type probably carries too many responsibilities, but breaking it apart is difficult for other reasons (perhaps too many things depend on it and changing it would be expensive). You can extract smaller interfaces that support the individual responsibilities, but still have the same class adopt it. Doing so opens up opportunities for further refactoring and testing.

In this episode we examine the Liskov Subtitution Principle, which stresses the importance of the strong relationship a type has with its super type. Understanding LSP can help you identify when you are missing an important abstraction, or perhaps when inheritance is being abused as a tool.

The Open Closed Principle (or OCP) states that a class should be open for extension, but closed for modification. The goal is to write classes that are more stable, and don't require constant changes themselves to support every scenario the software encounters. Instead, having a stable class to inherit from can provide a nice extension point for our software to customize it for other needs.

In this episode we'll examine a type that has too many responsibilities and refactor it into multiple types, each with their own responsibility.

This episodes kicks off a new series on SOLID principles for improving at object-oriented design. Writing better code means writing code that costs less to change, which can be a crucial factor in delivering project successfully. In this series we will see how these principles apply to Swift.

UITableView can support scrolling through many rows of data, however fetching large amounts of remote data can slow down your app, use up too much memory, and bog down your web server. This is all wasteful if users aren‘t ever going to scroll down that far. In this episode you‘ll learn how to perform automatic UITableView pagination using an easy technique.

Our applications often depend on 3rd party services that require API tokens, Client IDs & Secrets, Passwords and other sensitive data. This data should not be checked into your source repository for numerous reasons. Having control over who has access to keys is important, especially for larger organizations. In this episode I will show you one technique for managing these keys without having to check them into git.

In this episode we continue with our caching example, this time introducing a new type that will handle the caching for us, as well as wrapping the response type into a new type that will indicate to the view controller if the response was served from the cache or from the network. We end the episode by implementing Equatable so that our store can avoid needless double callbacks if the data has not changed.

In a recent project I leveraged the Codable protocol to save API responses to disk to make the application more responsive (and to have an offline mode). I was happy with the results. In this episode we will add some caching to an existing application, saving JSON responses to the caches directory on the device.

Codable is a great API, but sometimes real APIs can be tricky to model. In this episode we’ll examine a real use case of an API that returns a collection of elements, each of them similar but specified by a type. We’ll leverage Codable and inheritance to create a representation of this structure and show how you can peek into the container in order to determine what type to decode.

In this episode we extract our camera preview layer into its own view so we can add subviews. We’ll use this to add a flash button control to the UI, which will require us to learn about locking the device and controlling the camera’s "torch".

I got a tip from a subscriber about the method I used to capture the photo in the last episode. Since we're capturing the data using the preset we chose for processing the rectangles, we are bound to that preset when we export to an actual photo. By using AVCapturePhotoOutput, we can have much more control over the format, size, and quality of the resulting image. In addition, since we are leveraging the SDK for capturing the photo, we benefit from things like auto-flash, HDR, auto focus, and the built-in camera shutter sound. (Yay for deleting code!) The end result might not look very different on device, but if you are taking that image somewhere else to do OCR or other processing on it, a higher quality image is important.

Sometimes we need to create a quick icon and we don't have a designer handy. Usually in these situations I lean on icon packs like Parakeet Primaries or Glyphish. Lately I’ve needed some icons that aren’t available in packs like these, or the license isn’t suitable for what I want to use it for. In those situations I use Sketch to create icons myself. I’m no graphic designer, but I have found it helpful to know how to create basic things and export them for use in iOS projects. In this episode I design 2 icons that we’ll use in a future episode.

In this episode we take the captured image and run the perspective correction filter on it in order to turn a skewed rect back into a flat rectangle. We then display the image on the screen for a few seconds as a preview mechanism.

In this episode we implement features that make the app feel more like a camera. When tapping the screen, we play the system camera shutter sound using AudioServices, then we add a small but useful flash effect to reinforce the fact the user took a photo. We'll also talk about a strategy for capturing the image by using a flag.

We get smarter about drawing, this time leveraging a custom path so we can display non-rectangular outlines.

In the last episode it was clear our coordinate math was wrong. But why? We will answer that question and solve the problem. We also add code to hide the box if it hasn’t detected a rectangle for a few seconds.