help with asyncCall or coroutines to show a loader/spinner when app is hanging

pie

Hi, I think I need some help on how to use coroutines or asyncCall.

I have an app using imgui that might be hanging here and there on older devices because it needs to load a bunch of entries from an sqlite db.
My goal would be to display something that moves/rotates/changes while those values load, but I am struggling already to understand how to manage this in the least invasive way (the app is working, I'd like to avoid rewriting a lot of stuff).

This pseudocode represent what happens now:

function sqliteload(query) local stmt = {} local output = {} local db = sqlite3.open("|D|"..dbfilename) stmt = db:prepare(query)   for data in stmt:nrows() do output[#output+1] = data end   return output end     local List = {} function drawWindow() --imgui stuff to draw window and display the content of List   if ui:button("load list") then List = sqliteload("SELECT * FROM stuff") --this is where the app might hang, therefore I'd like to call the loader just before this line and show it until I have a complete list from sqliteload(). end   end   function enterframe() ui:newFrame(e.deltaTime) drawWindow(ui) ui:render() ui:endFrame() end

How/where should I add my loader?
I thought I could use this approach https://forum.giderosmobile.com/discussion/comment/56498/#Comment_56498
Core.asyncCall(sqliteload) but I get an invalid argument (function expected, got table), and it makes sense since a table is what I am returning there.. so how do I do it?

Thank you

hgy29

pie said:

Core.asyncCall(sqliteload) but I get an invalid argument (function expected, got table), and it makes sense since a table is what I am returning there.. so how do I do it?

I think yout actually wrote

Core.asyncCall(sqliteload("request"))

while it should have been called like

Core.asyncCall(sqliteload,"request")

.
But you'll lose the result of your call. Your function should either set the result as a variable that will be picked up by your enter frame call once populated, or call a callback function with the result, etc.

EDIT: You can also do

Core.asyncCall(function() List = sqliteload("SELECT * FROM stuff") end)