How to make "for..in" in loop wait for a function to execute in swift?

Question

I am creating a personal playlist in my app using songs that I am pulling from the Spotify SDK. Spotify songs have a uri which makes it so you can only play the tracks with the Spotify player which takes a single string uri and plays it, but I have an entire array of track URI's. To solve this I created a for..in loop to play each individual song, but what happens is it iterates through the entire array and only plays the last track uri in the array.

My question is: Is there a way to have the for..in loop wait for each item to finish playing before going through the rest of the array?

array of track uri's

function that plays each individual URI

You should add the code to your post (using the code formatting) instead of linking an image. This will allow others to easily read it or copy/paste to test a solution. — Paolo
– Paolo, Commented Aug 3, 2017 at 15:35
Welcome to StackExchange. I just fixed the image tags in your question. However, please to not post your code as images. Instead, provide them as text. — user1438038
– user1438038, Commented Aug 3, 2017 at 15:35

David Pasztor · Accepted Answer · 2017-08-03 15:38:25Z

1

If you want to play the songs sequentially (like a playlist), you need to add them a serial DispatchQueue. The serial queue will ensure that only one item is executed inside it at a time and hence only one of the asynchronous requests will execute at a time, meaning that each iteration of the for loop will wait for the previous one to finish.

let queue = DispatchQueue(label: "serial")
for song in playAllSongs{
    queue.async{
        //put all code here that you had inside the for loop
    }
}

answered Aug 3, 2017 at 15:38

David Pasztor

55.1k9 gold badges97 silver badges130 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Maxime · Accepted Answer · 2017-08-03 15:39:59Z

0

You shouldn't use a for...in loop to play all songs. Even if you use a synchronous block I'm not sure it will works. A solution is to listen a Notification or to have a completion block called when a song is ended. Then you just have to play the next one in the array.

answered Aug 3, 2017 at 15:39

Maxime

1,3941 gold badge16 silver badges44 bronze badges

Collectives™ on Stack Overflow

How to make "for..in" in loop wait for a function to execute in swift?

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related