Wait for Promise to resolve or reject

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#1

I started experimenting with Promises and I don’t know how to wait for Promise to resolve or reject.

I tried

promise:await(function(_, result)
   print(result)
end)

but it doesn’t print anything.

1 Like
#2

Await is the correct way to wait for a Promise to complete. You need to show more code than this, specifically the Promise you’re awaiting on.

3 Likes
#3

This is the module script with functions that use promises:
изображение

And this is the script where I get the result:
изображение

1 Like
#4

You don’t need to pcall inside a Promise since errors during execution are translated into rejections:

return Promise.new(function (resolve)
    resolve(player1:IsFriendsWith(player2))
end)

In any case though, await is a method call that returns the results of the Promise so you’re not using it correctly here. What you want instead is to assign the returns to variables:

local resolved, result = promises:IsFriendsWith(Players.LocalPlayer, player.UserId):await()

andThen is what you’re looking for if you want to chain a result handler onto the Promise since your await right now is currently being used like andThen.

promises:IsFriendsWith(Players.LocalPlayer, player.UserId):andThen(function (result)
    local append = if result == true then "friends" else "not friends"
    print("Players are " .. append)
end)

Side note: make sure to :catch() rejections so you can handle them in your code! You can still chain Promises off of a catch which itself returns a Promise.

3 Likes
#5

This seems to be working, thank you! Don’t even know why I though that it should be like this (probably because how :andThen is working).

Actually, I have a chain of these functions and they are made for my custom player list to get icons next to the player’s username. In player list these icons should have a priority, so thats why I don’t use :andThen. :slightly_smiling_face: