I must not have at least 1 brain cell...

[TheDevster]

I can't figure out why I cannot get this to work. I am missing something simple I am sure...

I will admit I am new to LUA and new to Redm/Fivem framework (Python / Ruby guy).

First, I have the resource added and started in the resource.cfg
At the top of my client and server I have placed this:
Callbacks = exports['callbacks']:FetchCallbacks()

I have a RegisterNUICallback() that calls the Trigger (I assumed this could work very similar to the register command example)

  local storeprice
 print("REGISTER NUI CALLBACK IS REACHED")
print("STORE ID IN NUI CALLBACK IS: ", store_id)
  Callbacks:TriggerCallback('get_store_cost', function(store_id)
    print("DATA SENT TO TRIGGER CALLBACK: ", store_id)
  end, storeprice)
  cb({price = storeprice})
end)

The two print statements before the Callbacks:TriggerCallback work. The third inside the Callbacks:TriggerCallback never gets called.

And on my Server side I have this:

  Callbacks:RegisterCallback('get_store_cost', function(idstore, source, cb)
    print("Made it here")
    MySQL.Async.fetchAll('select price, store_bank from stores WHERE store_id=@id_store', 
    {
      ['id_store'] = idstore
    }, function(results)
      if #results > 0 then 
        total_price = round_monies(results[1].price + results[1].store_bank)
        cb(total_price)
      end
    end)
  end)
end
registerCallbacks()

The print "Made it here" never gets executed.

[itsxScrubz]

It's because the syntax is Callbacks:TriggerCallback(callback_name, function, data_being_sent)

[itsxScrubz]

Since you flipped the data being returned with the data you're trying to send, the query isn't finding anything and therefor never triggering the callback function.

[TheDevster]

So a modification, such as below should work right? Where callbackname is 'get_store_cost', function is where callback data will be stored (yes?), and the last parameters being the data from client that is being sent to server?

store is a table that gets sent as the data from client to the server.

 local storeprice
  Callbacks:TriggerCallback('get_store_cost', function(data) 
    print(data)
    storeprice = data
  end, store)

and my server side still good?

  Callbacks:RegisterCallback('get_store_cost', function(data, source, cb)
    print("Made it here")
    print("SOURCE", source)
    MySQL.Async.fetchAll('select price, store_bank from stores WHERE store_id=@id_store', 
    {
      ['id_store'] = source.id
    }, function(results)
      if #results > 0 then 
        total_price = round_monies(results[1].price + results[1].store_bank)
        cb(total_price)
      end
    end)
  end)

I assume with registering it's the same order of functions right?

[itsxScrubz]

['id_store'] = source.id

Since your sending data thru the callback, this should be ['id_store'] = data
function(data_sent_from_client, source, callback_function)

[TheDevster]

Nice! Ok I got it to work with your help! I really appreciate that. I do notice that if I change the code and restart my resource, I also have to restart the callback resource or I end up with errors like this:
[script:callbacks] SCRIPT ERROR: citizen:/scripting/lua/scheduler.lua:853: bad argument #1 to 'unpack' (table expected, got nil)

Hopefully I can gain some of my brain cells back now that I am heading in the correct direction..

[itsxScrubz]

It's due to how the resource is written. When you restart the callbacks, the table that holds them via: [ Callbacks = exports['callbacks']:FetchCallbacks() ] no longer exists. All you would have to do is just reassign the variable with the export again. These callbacks were in my framework, and when you restart a resource it automatically refreshes that component. Since they are standalone, this isn't the case!

But glad to be of help.