NOTE: The second installment of this article, “Controlling chaos: Error Handling in Swift 4 with do, try, catch, defer, throw, throws, Error, and NSError,”, has just been released.
In this tutorial, the first in a series of tutorials, we’re going to discuss the arduous topic of looking for unexpected values, events, and conditions that arise during program execution, using a technique I like to call “error checking.” Today, I’ll concentrate on the reasons why you should check for errors. I’ll mention a number of techniques I use but leave detailed discussion of those techniques and sample code to subsequent articles. The purpose of this tutorial is to convince you to make use of error checking in your apps. You ignore errors at your own dire peril. This is sink or swim. If you put out a crappy app, no one’s going to use it because you’ll get a bad reputation at Internet speed, and employers/customers will be more than happy to leave you behind forever for other app developers who aren’t too lazy to write quality code.
Continue reading “Controlling chaos: Why you should care about adding error checking to your iOS apps”
The original article – Working with Core Bluetooth in iOS 11 – was published on appcoda.com.
[Download the Xcode 9 project from GitHub so you can follow along with my code explanation and try iOS
Core Bluetooth features yourself!]
As iOS developers, we’re very aware that humans love connectivity. Obviously, we love to communicate with each other using wireless devices. More recently, we’ve come expect that we can communicate with what once were considered standalone, ordinary devices. We’ve come to love, even expect, that some of those wireless devices can gather and analyze data about ourselves (usually “wearables”). So many devices have become intrinsic parts of our lives that we’ve coined a now commonly-used phrase, the “Internet of Things” or “IoT.” There are now billions of wireless, communicable devices on the planet. In this tutorial, we’re going to focus on just one segment of the IoT: Bluetooth®.
I’ll explain the essential concepts behind Bluetooth® technology, show you how getting proficient in Bluetooth® software development presents you with a tremendous career opportunity, remind you that you can’t distribute an app that uses Bluetooth® without determining if you need to go through “qualification,” provide you with an overview of Apple’s
Core Bluetooth framework (see also here), and finally, walk you through the development of an iOS app in Swift 4 that monitors a person’s heart rate via
Core Bluetooth via a Bluetooth® device.
Continue reading “Tutorial: Core Bluetooth communication with a wearable in Swift 4”
NOTE: My latest tutorial has just been released, which uses the code shown herein to introduce error handling in Swift 4.
[Download the Xcode 9 project from GitHub so you can follow along with my code explanation and try iOS file management features yourself!]
How many of you have written iOS apps that work with files? I’m talking about developing apps that read, write, create, copy, move, and delete files in the app’s sandboxed file system. I’m not talking about reading an image from your app bundle so you can display it on screen, like so:
let image = UIImage(named: "background.png")
I’m talking about apps like Adobe Photoshop Express which is only useful if it can edit image files; Apple’s Pages and Numbers apps which are only useful if they can edit word processor and spreadsheet/chart files, respectively; and, Microsoft Word which is only useful if it can edit word processor documents. Yes, you can solely work from/in the cloud with all these apps, but you can also opt to store files locally on your devices. What if you open an email attachment or download a file from Safari? I guarantee you that many apps with associations to certain file extensions store those attachments or downloads locally first for editing and display, and only later sync files with iCloud or Dropbox.
Continue reading “iOS file management with FileManager in protocol-oriented Swift 4”