Archives for November 2014

DateComponents — Class Reference

Last updated on August 12, 2020

As mentioned last time in my post Date — Class Reference, now we go a bit more in depth with DateComponents. In my opinion, this is the real powerhouse for dealing with time in Swift or Objective-C. When I was first learning iOS, I looked, understandably, at Date to work with dates. As such, a test project used Date and it’s initializers, including NSTimeInterval. When I had mentioned that at my local NSCoderNight, I was told to look into DateComponents, and boy was that good advice! Not only is it a pain to calculate the seconds for the intervals you want, what about dealing with Daylight Savings Time, leap years, or just plain different calendars! Now with DateComponents, I can set a date in a way that I understand, and in concert with Date and Calendar, it will even deal appropriately with the intricacies of calendars without me having to do so myself.

DateComponents can be used to either specify a specific date, or to specify a timespan in your Swift iOS apps. There is no difference between the uses as far as DateComponents is concerned you just set the appropriate components (year, day, hour, second, etc).
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Date — Class Reference

Last updated on August 12, 2020

An NSDate object specifies a particular point in time. Despite “date” being in its name, it really stores time, of which the date is a component. Under the hood, NSDates (as far as the public superclass we can see is concerned) are specified as a number of seconds past a reference date. NSDate’s reference date is the first moment of January 1, 2001 in the GMT timezone. These seconds are stored as a Double, which allows NSDate to range from milliseconds to years. What we see as an NSDate is actually an abstract public superclass for a cluster of classes related to dates. The internal classes are private, so talking about them here wouldn’t be particularly helpful, and it is probably best not to mess with them anyway.

Since Swift 3 though, most “NS” prefixes were removed from the Swift Standard Library, so now it is simply called “Date”. If you need to save a timestamp for something in your iOS app, or maybe have a countdown timer for an app or game, you will be dealing with the Date class, so let’s take a look at it.
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Add sharing to your Swift app via UIActivityViewController

Last updated on August 12, 2020

In several iOS apps, such as Safari or the Camera app, you can click a button that brings up an interface that makes it easy to send or share what you are looking at via messages, Twitter, Facebook, etc. That interface is known as the UIActivityViewController. When I first learned about it, I didn’t even know what to search for. I think I originally started with “share sheet” and went on from there, so it may seem silly to point out something so obvious, but when I first tried, I knew what I wanted, I just had no idea what it was called.

If you’ve paid any attention to WWDC a few years, you have probably saw that this is the new home for Share and Action extensions. Today though, we are just going to cover the built in aspects of using UIActivityViewController in your Swift app. We will cover those sometime later.
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Archives for November 2014

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