Save and load data with JSON

[Dzsozi (h03)]

Hello! I would like to use tables for my vehicle system to save data, since I really want to have a good performance. Whatever, so I tried using toJSOn and fromJSON but I don't really understand how that works. I want to save every vehicles' blinker state/side when the resource stops and set it back when the resource starts. How can I do that with tables? Here's my current code, I tried lots of different ways but couldn't manage to get it working. I would appreciate if someone could help me out!

local function toggleIndicator(key,keyState)
	if isTimer(spamTimer) then return end
	
	for k, vehicle in pairs(getElementsByType("vehicle")) do
		local driver = getVehicleOccupant(vehicle)
		if driver == localPlayer then
			if (keyState == "down") then
				spamTimer = setTimer(function() spamTimer = nil end, 1000, 1)
				indicatorInfo[vehicle] = indicatorInfo[vehicle] or {}
				local indicatorState = indicatorInfo[vehicle]["side"] or nil
				
				if indicatorState then
					--removeEventHandler("onClientRender", getRootElement(), startIndicator)
					indicatorInfo[vehicle]["side"] = nil
					handleIndicatorLights()
					return
				end
				
				if key == blinkerLeft then
					indicatorInfo[vehicle] = {
						["side"] = "left",
					}
				elseif key == blinkerRight then
					indicatorInfo[vehicle] = {
						["side"] = "right",
					}
				else
					indicatorInfo[vehicle] = {
						["side"] = "both",
					}
				end
			end
		end
	end
end

addEventHandler("onClientResourceStart", getResourceRootElement(getThisResource()),
	function()
		bindKey(blinkerLeft, "down", toggleIndicator)
		bindKey(blinkerRight, "down", toggleIndicator)
		bindKey(blinkerBoth, "down", toggleIndicator)
		
		for k, vehicle in pairs(getElementsByType("vehicle")) do
			indicatorInfo[vehicle] = indicatorInfo[vehicle] or {}
			indicatorInfo[vehicle]["side"] = fromJSON(data)
		end
	end
)

addEventHandler("onClientResourceStop", getResourceRootElement(getThisResource()),
	function()
		for k, vehicle in pairs(getElementsByType("vehicle")) do
			if indicatorInfo[vehicle] then
				local data = toJSON({indicatorInfo[vehicle]["side"] or nil})
			end
		end
	end
)

I get this error with the current code, but I don't know how to fix it: Bad argument @ 'fromJSON' [Expected string at argument 1, got nil]

[MIKI785]

I don't see you saving it anywhere though.

addEventHandler("onClientResourceStop", getResourceRootElement(getThisResource()),
	function()
		for k, vehicle in pairs(getElementsByType("vehicle")) do
			if indicatorInfo[vehicle] then
				local data = toJSON({indicatorInfo[vehicle]["side"] or nil})
			end
		end
	end
)

You store the data in a local data and that's it. So the data is then lost, it never gets saved anywhere.

addEventHandler("onClientResourceStart", getResourceRootElement(getThisResource()),
	function()
		bindKey(blinkerLeft, "down", toggleIndicator)
		bindKey(blinkerRight, "down", toggleIndicator)
		bindKey(blinkerBoth, "down", toggleIndicator)
		
		for k, vehicle in pairs(getElementsByType("vehicle")) do
			indicatorInfo[vehicle] = indicatorInfo[vehicle] or {}
			indicatorInfo[vehicle]["side"] = fromJSON(data)
		end
	end
)

Here the data is undefined/nil. You never give it a value.

You should save the data somewhere, database would be the best but if that's too complex then try simply saving it into a file and then read that file when the resource starts.

[Dzsozi (h03)]

If I save the data in a file how should I do that? Every vehicle’s data in a new line? Or how should I get which vehicle has the data?

Database seems a bit more complicated and also I don’t want to get it on server side. I am looking for the best performance for my scripts. What do you think which is the most performance friendly solution for that?

Edited September 21, 2018 by Dzsozi (h03)

[JeViCo]

11 minutes ago, Dzsozi (h03) said:

If I save the data in a file how should I do that? Every vehicle’s data in a new line? Or how should I get which vehicle has the data?

Database seems a bit more complicated and also I don’t want to get it on server side. I am looking for the best performance for my scripts. What do you think which is the most performance friendly solution for that?

(server-side !!!) use setElementData for each vehicle. Load your data after on resource start and remove it (removeElementData)

[Dzsozi (h03)]

2 minutes ago, JeViCo said:

(server-side !!!) use setElementData for each vehicle. Load your data after on resource start and remove it (removeElementData)

I don't really want to use setElementData, I rather prefer tables on client side for this, if is that possible. Probably it is, since the script works right now, I just need to know how to store the vehicles' data when I stop/start/restart the resource. But I don't think that I need element datas on server side for that, since this is not something like I would need to be aware of to people change it's data value with cheat engine or something.

[JeViCo]

3 hours ago, Dzsozi (h03) said:

I don't really want to use setElementData, I rather prefer tables on client side for this, if is that possible. Probably it is, since the script works right now, I just need to know how to store the vehicles' data when I stop/start/restart the resource. But I don't think that I need element datas on server side for that, since this is not something like I would need to be aware of to people change it's data value with cheat engine or something.

This might be a little bit offtopic but i 100% understand you - that's quite nasty problem. Anyway you can't avoid it all the time. This page may help you. Also you can attach other information elements such as ID, type, etc so you can manage them with the least risk

Edited September 21, 2018 by JeViCo

[pa3ck]

There are couple of questions that need to be answered first... you only mention client side, so you don't care whether the blinkers are same for everyone? If so, you can use XML or JSON string in a client file - remember that fromJSON takes a string and converts it into a LUA table and toJSON converts a LUA table to a string that you can store in a file, once you converted the string back to LUA table, you can handle it as any other table.

[MIKI785]

I just noticed that he uses an element to index the table, that can't be saved into a file. You'd have to use a different way of knowing which vehicle you're talking about. setElementID and getElementByID could be the answer,