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iOS Build an Interactive Story App with Swift Adding Sound Effects Playing a System Sound

Ayo Omotosho
Ayo Omotosho
4,855 Points
Posted by Ayo Omotosho
Ayo Omotosho
4,855 Points

App Crashing after adding SoundEffects Code

After adding all the code for the sound effects as instructed by Pasan, once the app loads up and i input a name and click continue, the App just crashes. I think it has something to do with a force unwrapped line of code in there, not really sure though as i am still a novice at this. Some assistance with this would be highly appreciated.

Audio.SwiftFile

import Foundation import AudioToolbox

extension Story {

var soundEffectName: String {
    switch self {
    case .droid, .home: return "Happy Ending"
    case .monster: return "Ominous"
    default: return "Page Turn"
    }
}

var soundEffectURL: URL {
    let path = Bundle.main.path(forResource: soundEffectName, ofType: "wav")!
    return URL(fileURLWithPath: path)
}

}

class SoundEffectsPlayer { var sound: SystemSoundID = 0

func playSound(for story: Story) {

    let soundURL = story.soundEffectURL as CFURL
    AudioServicesCreateSystemSoundID(soundURL, &sound)
    AudioServicesPlaySystemSound(sound)

}

}

Ayo Omotosho
Ayo Omotosho
4,855 Points
Ayo Omotosho
Ayo Omotosho
4,855 Points

Console: "fatal error: unexpectedly found nil while unwrapping an Optional value"

3 Answers

Marlon Henry
Marlon Henry
6,885 Points
Marlon Henry
Marlon Henry
6,885 Points

Good old guard statement can help

var soundEffectURL: URL {
    guard let path = Bundle.main.path(forResource: soundEffectName, ofType: "wav") else{ return URL(string:"in here put a value you know works")!}
    return URL(fileURLWithPath: path)
}
Ayo Omotosho
Ayo Omotosho
4,855 Points
Ayo Omotosho
Ayo Omotosho
4,855 Points

Thanks Marlon. App isn't crashing anymore. However, the sound effects aren't playing at all.

Thanks for your help though!

Marlon Henry
Marlon Henry
6,885 Points

I would say look at the spelling and spacing in your string names. If those are not exactly as you have those wav files in your project then it won't work, I also advise against having spaces in your file names if you can avoid it.

kols
kols
25,098 Points
kols
kols
25,098 Points

I did the same thing, and Marlon is correct on both counts (thanks, Marlon!):

  1. Using a guard statement instead of force unwrapping is really the better way to go; and,
  2. The crash, in this case, is caused by having spaces between words (e.g., "Happy Ending" instead of "HappyEnding") in that initial Story extension...

Pasting correct code below: 

extension Story {

    var soundEffectName: String {
        switch self {
        case .droid, .home: return "HappyEnding"
        case .monster: return "Ominous"
        default: return "PageTurn"
        }
    }

    // Note: A guard statement would be ideal instead of force unwrapping as shown below:

    var soundEffectURL: URL {
        let path = Bundle.main.path(forResource: soundEffectName, ofType: "wav")!
        return URL(fileURLWithPath: path)
    }
}
Marlon Henry
Marlon Henry
6,885 Points

Glad I could help. I code all day at work, so I just cruise the forums to help folks since I didn't have much help when I started in my early days.

Emre Havan
Emre Havan
8,569 Points
Emre Havan
Emre Havan
8,569 Points

Thanks a lot @Marlon! I could get rid of the error, but my code still does not play any sound when I go through the story. Anyone has an idea why this might be happening?

Marlon Henry
Marlon Henry
6,885 Points

Sorry I'm now seeing this. Have you been able to fix the issue or do you still need help?