Callbacks

The callback system allows server scripts to handle requests from clients and vice versa.

RegisterServerCallback

Register a callback handler on the server that clients can trigger.

KOJA.Server.RegisterServerCallback(key, handler)

Parameter	Type	Description
key	string	Callback identifier
handler	function(source, payload, cb)	Handler — call cb(result) to respond

Example

KOJA.Server.RegisterServerCallback('myScript:getShopItems', function(source, payload, cb)
    local items = MySQL.query.await('SELECT * FROM shop_items WHERE category = ?', { payload.category })
    cb(items)
end)

Triggered from the client:

KOJA.Client.TriggerServerCallback('myScript:getShopItems', { category = 'food' }, function(items)
    for _, item in ipairs(items) do
        print(item.name, item.price)
    end
end)

TriggerClientCallback

Trigger a callback registered on a specific client from the server.

KOJA.Server.TriggerClientCallback(key, playerId, payload, callback)

Parameter	Type	Description
key	string	Callback identifier
playerId	number	Target player server ID
payload	any	Data to send
callback	function(...)	Called with the client's response

Example

KOJA.Server.TriggerClientCallback('myScript:getLocalCoords', source, nil, function(coords)
    print('Player is at:', coords.x, coords.y, coords.z)
end)

Registered on the client:

KOJA.Client.RegisterClientCallback('myScript:getLocalCoords', function(payload, cb)
    local pos = GetEntityCoords(PlayerPedId())
    cb({ x = pos.x, y = pos.y, z = pos.z })
end)

TriggerCallback (internal)

Manually trigger an already-registered server callback from another server script.

KOJA.Server.TriggerCallback(key, source, payload, cb)

This is mainly for internal use. Prefer RegisterServerCallback + client triggers for the standard pattern.