Introduction

The iPhone, with its sleek design and powerful features, has become an essential tool in our daily lives. One of the features that makes it stand out is its notification system, which allows us to receive important messages and alerts on the go. However, have you ever wondered how Apple manages to make those notifications sound so pleasant? In this article, we will explore a lesser-known feature that allows us to change the notification sound of our iPhone using songs from the iPod library.

Background

When you set an alarm on your iPhone, it generates a unique ID for that specific alarm. This ID is used to trigger the corresponding notification sound when the alarm goes off. The good news is that this ID can be mapped to any song in your iPod library, allowing you to choose the one you want to play as the alarm sound.

Understanding NSUserDefault

In our first approach, we will use the NSUserDefault class to store the URL of the selected song from the iPod library. This class is a convenient way to store small amounts of data in the app’s settings.

Setting up NSUserDefault

To set up NSUserDefault, you need to import it into your project and create an instance of it in your app delegate or anywhere else where you want to access the stored value. Here is a simple example:

import UIKit

class AppDelegate: UIResponder, UIApplicationDelegate {
    var userDefaults = NSUserDefault.standard()

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // Create an instance of NSUserDefault
        return true
    }
}

Retrieving and Setting the URL

Once you have created an instance of NSUserDefault, you can use it to store and retrieve values. To set a value, use the setValue(_:forKey:) method:

userDefaults.setValue("https://example.com/song.mp3", forKey: "selectedSong")

To retrieve a value, use the value(forKey:) method:

let selectedSongURL = userDefaults.value(forKey: "selectedSong") as? String
print(selectedSongURL)

Using NSUserDefault in didReceiveNotification

In our case, we want to use the URL stored in NSUserDefault to play the song when the alarm goes off. To do this, we need to override the didReceiveNotification(_:NSDictionary) method of the app delegate and pass the URL to the MPMediaPlayer class:

override func didReceiveNotification(_ notification: Notification) {
    super.didReceiveNotification(notification)
    
    let selectedSongURL = userDefaults.value(forKey: "selectedSong") as? String
    
    if let selectedSongURL = selectedSongURL {
        let player = MPMediaPlayer()
        
        // Create a URL from the stored string
        guard let url = URL(string: selectedSongURL) else { return }
        
        do {
            try player.loadContentWithItemIdentifiers([url], options: nil)
            player.play()
        } catch {
            print("Error playing song:", error)
        }
    }
}

Coping the Selected Song to the App’s Document Folder

In our second approach, we will copy the selected song from the iPod library to the app’s document folder and use it as the alarm sound.

Getting the URL of the Selected Song

To get the URL of the selected song, you need to use the MPMediaItem class:

let selectedSong = MPMediaItem(itemURL: url)

Copying the Song to the App’s Document Folder

Once you have the URL of the selected song, you can copy it to the app’s document folder using the FileManager class:

guard let fileManager = FileManager.default else { return }
let documentsPath = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let songFileURL = documentsPath.appendingPathComponent("song.mp3")
try? fileManager.copyItem(at: url, to: songFileURL)

Playing the Song

To play the copied song as the alarm sound, you can use the MPMediaPlayer class:

let player = MPMediaPlayer()
player.loadContentWithItemIdentifiers([songFileURL], options: nil)
player.play()

Conclusion

Changing the notification sound of your iPhone using a song from the iPod library is a unique feature that not many people know about. By using NSUserDefault or copying the selected song to the app’s document folder, you can achieve this functionality in your own app.

While both approaches have their advantages and disadvantages, understanding how they work will help you make an informed decision on which one to use for your specific needs.

Last modified on 2024-08-15