Weekly bite-sized screencasts on iOS development.

Designing a Custom Download Button - Part 1

Episode #242 | 14 minutes | published on 10/27/2016
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In this episode we create a custom control to serve as our download button. We start by creating a circular progress indicator using CAShapeLayer, then move on to subclassing UIControl to provide our image view and touch handling.

File Downloads - Part 3

Episode #241 | 17 minutes | published on 10/27/2016
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In this episode we take the download state and progress notifications and update the user interface to reflect this state. We'll see how to translate the notification into the indexPath for that episode row, and how to fake a change related to the fetched results controller to trigger a reload of the content. We will leverage the RateLimit library to save periodic changes in progress to the model without overwhelming Core Data.

File Downloads - Part 2

Episode #240 | 32 minutes | published on 10/20/2016
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In this episode we create a DownloadInfo model in CoreData in order to track the state of a download, separate from any view controller.

File Downloads - Part 1

Episode #239 | 30 minutes | published on 10/06/2016
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Downloading large files on iOS represents some unique challenges. Downloads should occur in the background, not confined to a particular view controller. They should be able to report progress on multiple screens, and should be robust enough to survive application suspension and failing network conditions, and respect the user's cellular data plan. In this episode we start a series on downloading large files that will cover all of the above concerns.

Core Data in iOS 10

Episode #238 | 28 minutes | published on 10/04/2016
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iOS 10 brings some welcome improvements to Core Data, including the all new NSPersistentContainer class. With this release, Apple has created a streamlined API that captures the most common uses of Core Data in iOS applications. In this episode we'll take a look at NSPersistentContainer, as well as the new code-generation capability in Xcode 8.

Swift 3

Episode #237 | 20 minutes | published on 09/29/2016
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Swift 3 is now out and contains a host of new features and syntax changes. In this episode we'll look at a few of the more common changes you'll run into when upgrade projects to Swift 3 including implicit method argument labels, dropping the NS prefix on a bunch of classes, and the new Swift API naming guidelines.

Creating Sticker Pack Applications

Episode #236 | 7 minutes | published on 09/15/2016
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Now that iOS 10 is out, we can now create sticker packs to use in iMessage. In this episode we'll create a sticker pack using some artwork made by Jory Raphael, the very same designer who makes the lovely artwork you see on each episode. This particular sticker pack will be available soon in the App Store!

Working with the Pasteboard

Episode #235 | 17 minutes | published on 09/12/2016
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In this episode we take a look at UIPasteboard, allowing us to inspect, copy, and paste content on the system pasteboard as well as your own custom pasteboards. We'll also look at adding multiple representations of the same item to be a better OS citizen, for instance by copying rich text alongside plain text.

Universal Links

Episode #234 | 16 minutes | published on 09/02/2016
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Universal Links is a great feature that allows us to render content in an app when a user hits a known URL, instead of opening Safari. For content-based applications, this can be especially useful, as often records that exist on the web also exist in the app. We'll leverage our work from Episode 231 on Shared Web Credentials and extend the demo app to take advantage of Universal Links.


Episode #233 | 18 minutes | published on 08/25/2016
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Writing Autolayout constraints from code can be quite tedious. SnapKit, the Swift-friendly successor to Masonry, is a friendly DSL that allows creating and updating constraints easy and readable. In this episode we use SnapKit to build out a simple interface mockup using Autolayout completely in code.

Calculating Spring Velocity

Episode #232 | 8 minutes | published on 08/19/2016
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UIView has an incredibly useful spring-based animation API, but it can be difficult to know what to use for the damping and initial spring velocity parameters. In this episode, we'll break down how to compute the velocity value using the values we get from our UIPanGestureRecognizer and a little math.

Shared Web Credentials

Episode #231 | 15 minutes | published on 08/11/2016
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In this episode we implement shared web credentials with a server, allowing users to automatically enter credentials in our app if they've already done so in Safari. We cover building a Sinatra app for our server, deployment to Heroku for free SSL and a unique domain, and adding the appropriate entitlements to our app.

Interview with David Smith

Episode #230 | 43 minutes | published on 07/29/2016
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In this episode we have a special guest: "Underscore" David Smith, the creator of Activity++! In this episode we chat about the implementation details of Activity++, and how it differs from the one we've been building.

Let's Build Activity++ - Part 7

Episode #229 | 13 minutes | published on 07/22/2016
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We build our activity streak detection algorithm, testing it along the way with Quick and Nimble.

Let's Build Activity++ - Part 6

Episode #228 | 14 minutes | published on 07/14/2016
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In this episode we allow for generating health data for use in the iOS simulator, where HealthKit data will not be available. We then create some known streaks to make the streak detection and UI decoration easier to test. We end the episode by setting up Quick and Nimble that we will use to test our streak generation algorithm.

Let's Build Activity++ - Part 5

Episode #227 | 28 minutes | published on 07/07/2016
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Continuing our series on building out our Activity++ clone, this time we hook up our application to HealthKit, displaying real data in the app from a device. We continue to use our wrapper type so that the application can still work in the simulator with randomized data, which also allows us to set up certain scenarios that we wish to test, such as streaks.

Let's Build Activity++ - Part 4

Episode #226 | 12 minutes | published on 07/01/2016
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In this episode we examine the scrolling performance of our activity ring views. We see that framerate suffers when scrolling quickly, then apply a few changes to bring scrolling performance back to 60 frames per second.

Let's Build Activity++ - Part 3

Episode #225 | 10 minutes | published on 06/23/2016
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This week we take our ring views and use them to create a collection view of rings, one for each day in an entire year.

Let's Build Activity++ - Part 2

Episode #224 | 16 minutes | published on 06/09/2016
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Continuing in our quest to create the interface behind Activity++, this time we introduce a randomize button, proper theme colors, labels for the rings, and highlighting when the goal for each ring has been met.

Let‘s Build Activity++!

Episode #223 | 38 minutes | published on 06/02/2016
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Let‘s attempt to recreate Activity++, an application by _David Smith. The app features a number of interesting interface elements that would be interesting to try to build ourselves! In this part we'll start out by replicating the ring views for a given day.