Learning Swift, 2nd Edition

Chapter 13. Multimedia and Location Attachments

In this chapter, we’ll improve the iOS app by adding more capabilities to the attachment system. We’ll add support for audio and video attachments as well as an attachment to store where the note was created.

In Notes, each attachment is represented by a file that’s added to the document’s Attachments directory and is managed by a view controller. Because of the architecture of the application, all we need to do to add support for different attachment types is to create a new view controller for it and add code to a couple of existing methods in DocumentListViewController to make them open the necessary view controller for each attachment type.

Let’s get started by building support for adding audio attachments.

Audio Attachments

This attachment we’ll add gives us the ability to record audio and play it back. We’ll do this by using the AVFoundation framework, which includes two classes: AVAudioRecorder will be used to record the audio, and AVAudioPlayer will be used to play it back.

Tip

We’re just scratching the surface of the iOS audio capabilities. You can learn more about the audio frameworks on iOS in Apple’s documentation.

First, we’ll add some icons that will be needed for this additional screen:

1. Open Assets.xcassets.

2. Add the Audio, Record, Play, and Stop icons to the asset catalog.

Next, we’ll add an entry to the list of attachment types for audio:

1. Add the following code to the addAttachment method:

     func addAttachment ...