Datasaver module doesn't load

unlying · February 2024

data = dataSaver.loadValue("data")

main.lua:226: attempt to call a nil value
stack traceback:
main.lua:226: in function

It works... mmm... two years ago)

Sorry, i haven't tracked what happened for two years:( It's my fault, I know.

May be anyone knows what should i change to start it works for me?

keszegh · February 2024

since luau, modules won't work i think. i changed my dataSaver file so that it is a class, so it starts like this, i think you get the point:

--module("dataSaver", package.seeall)
DataSaver = Core.class()
 
function DataSaver.init()
end
 
function DataSaver.saveValue(key, value)

MoKaLux · February 2024

https://wiki.gideros.rocks/index.php/Ftf_snippets#JSON_.40xxx
https://wiki.gideros.rocks/index.php/Ftf_snippets#JSON_V2_.40mokalux
maybe?

pie · February 2024

@unlying if I recall both answers apply.
you should load the json plugin in your project and make datasaver a class or a set of functions as in the attached file.
If I am not mistaken there is also the need to change Json to json (without capital).

I think this should work

Xman · February 2024

is it possible to resolve this data saver in luau?

Xman · February 2024

https://github.com/gideros/table.save/blob/master/table.save-0.94.lua

hgy29 · February 2024

@Xman, it depends on your use case. Saving strings/tables/numbers should be ok, but not functions nor userdata. What error do you get ?

Xman · February 2024

hgy29 · February 2024

Just checked and loadfile works here, actually Gideros uses it internally to mimic 'require' call. By the look of the error, it seems to complain that the searched file (sys.dat) doesn't exists in the document folder.
I misread your post, sorry, so in both cases it fails, but in luau the error message is absent. Yes it is that way in luau, it just returns nil.

Xman · February 2024

Then it can not tell if loadfile succeed.
I just hear about luau and have no ideas on how to migrate Lua to luau.
Just searched and found this document
https://luau-lang.org/compatibility
loadfile, dofile removed for sandboxing, no direct file access

Is there some guides on migration to luau if it's not possible to have a Lua release of engine.

pie · February 2024

@Xman what if you use io.open? Take a look at the datasaver functions posted above

I am in the middle of a lua to luau conversion, and gideros so far is telling me every issue one by one just by running the project, fixing the line, rerunning the project and so on.. it's tedious but it's feasible.

hgy29 · February 2024

@Xman, you could just check if loadfile returned a function or not maybe ?

Xman · February 2024

@pie @hgy29 Thanks for your supports.
Currently, change

require 'aaaa.bbbb' to require 'aaaa/bbbb'
check if loadfile returned a function or not

make the project run.
I can not guarantee every line of scripts has tested.
So welcome to share your experiences on migrate to luau on the forum.

If everyone shares some experiences, we will have a migrate guide.

hgy29 · February 2024

I will have a look at what I can do within Gideros to have require and loadfile behave more like lua 5.1

Xman · February 2024

for char in string.gfind("ABC", "([%z\1-\127\194-\244][\128-\191]*)") do
print(char)
end

gfind is not support in luau

output
attempt to call a nil value

MoKaLux · February 2024

Xman said:
for char in string.gfind("ABC", "([%z\1-\127\194-\244][\128-\191]*)") do
print(char)
end

--for char in string.gfind("ABC", "([%z\1-\127\194-\244][\128-\191]*)") do
for char in string.gmatch("ABC", "([%z\1-\127\194-\244][\128-\191]*)") do
	print(char)
end

added to https://wiki.gideros.rocks/index.php/Lua_to_Luau_conversion_guide

hgy29 · February 2024

Fixed loadfile/loadstring (https://github.com/gideros/luau/commit/1e9612653ee047f258c8473d94f43979adae7cea)
And require handling of dots: (https://github.com/gideros/gideros/commit/5a47f8fd12b7caf2fc50213a485bdd93fda974e9)

keszegh · 3:10PM

i'm using dataSaver which in turn uses json.encode and i get in the saved file such a table part:
"target":{"1":true,"2":false,"3":false,"1":true,"3":false,"2":false,"fx2":false,"fx1":true}

how is it possible that the same index appears multiple times? (i cannot pinpoint so far if i do anything strange, in any case it should not happen whatever i do in my code i guess)

also json.decode seems to decode this incorrectly (e.g., no value is given to "1"), which is the bigger problem.

any ideas?

hgy29 · 3:25PM

Wild guess: your lua table before encoding contains both 1 as a number and "1" as a string, but json only allows string keys so both are written as a string in the resulting file.
When reading back, one of those keys will be lost since they are the same.

Test:

require "json"
local target={ [1]=true, ["1"]=true}
for k,v in pairs(target) do print(k,v) end
local jsont=json.encode(target)
print(jsont)
target=json.decode(jsont)
for k,v in pairs(target) do print(k,v) end
print("String 1",target["1"])
print("Number 1",target[1])

MoKaLux · 3:37PM

keszegh I use this to save my data:
save_prefs.lua

require "json"
 
function saveData(filepath, value)
	local contents = json.encode(value)
	local file = io.open(filepath, "w") -- create file
	file:write(contents) -- save json string in file
	io.close(file)
end
 
function getData(filepath)
	local result, value
	local file = io.open(filepath, "r")
	if file then
		local contents = file:read("*a") -- read contents
--		value = json.decode(contents) -- decode json
		result, value = pcall(json.decode, contents) -- try to decode json
		io.close(file)
	end
	return result, value
end

This seems to work pretty well for my use case. Some more code:
init.lua

g_gconfigfilepath = "|D|myprefs.txt"
 
g_oprefcanvasw = 480 -- prefered default canvas size
g_oprefcanvash = 270 -- prefered default canvas size
g_prefcanvasw = 96 -- prefered default canvas size
g_prefcanvash = 96 -- prefered default canvas size

main.lua

function myLoadgPrefs() -- GENERAL
	local _result, mydata = getData(g_gconfigfilepath) -- try to read information from file
	if not mydata then -- if no general prefs file, create it
		mydata = {}
		-- general prefs
		mydata.g_oprefcanvasw = g_oprefcanvasw or 320
		mydata.g_oprefcanvash = g_oprefcanvash or 240
		mydata.g_prefcanvasw = g_prefcanvasw or 128
		mydata.g_prefcanvash = g_prefcanvash or 128
		-- create file and save datas
		saveData(g_gconfigfilepath, mydata) -- create file and save datas
		myLoadgPrefs() -- reload
	else -- general prefs file exists, use it!
		g_oprefcanvasw = mydata.g_oprefcanvasw or 320
		g_oprefcanvash = mydata.g_oprefcanvash or 240
		g_prefcanvasw = mydata.g_prefcanvasw or 128
		g_prefcanvash = mydata.g_prefcanvash or 128
	end
end
 
function mySavegPrefs() -- GENERAL
	local mydata = {} -- clear the table
	-- general prefs
	mydata.g_oprefcanvasw = g_oprefcanvasw or 320
	mydata.g_oprefcanvash = g_oprefcanvash or 240
	mydata.g_prefcanvasw = g_prefcanvasw or 128
	mydata.g_prefcanvash = g_prefcanvash or 128
	-- save new data
	saveData(g_gconfigfilepath, mydata)
end

When my app starts I load the the default values:

	-- load general prefs
	myLoadgPrefs()

Then any time I need to save my prefs some places in my code I use:

mySavegPrefs()

Some output example:

{
	"g_persp":false,
	"g_alphablend":true,
	"g_outline":false,
	"g_modelscalez":0.432804,
	"g_partsstyle":[
		{
			"offsety":0,
			"isvisible":true,
			"scalez":1,
			"scalex":1,
			"alpha":255,
		},
		{
			"offsety":0,
			"isvisible":true,
			"scalez":1,
		}
	],
	"g_blue":255,
	"g_alpha":255,
	"g_canvash":256,
	"g_canvasw":256,
}

https://wiki.gideros.rocks/index.php/Ftf_snippets#JSON_V2_.40mokalux

keszegh · 5:27PM

thanks @hgy29 and @MoKaLux , i think @hgy29 is right, initially the table has only values for indices 1,2 (As an array), then new value for 'fx1' is added and then this is saved. then when i load back i guess my app does not recognize that there is a '1' index and adds a 1 index and when it is saved next they become the same.
this will help me to make a workaround (checking and merging 1 and '1' if needed etc).

keszegh · 5:58PM

yes, a code like this illustrates well what happens:

require("json")
t1={1,2}
t1s=json.encode(t1)
print(t1s)
t2=json.decode(t1s)
t2["fx"]=4
t2s=json.encode(t2)
print(t2s)
t3=json.decode(t2s)
t3[1]=3
t3s=json.encode(t3)
print(t3s)
t4=json.decode(t3s)
t4s=json.encode(t4)
print(t4s)

and the output is the following:

[1,2]
{"1":1,"2":2,"fx":4}
{"1":3,"1":1,"fx":4,"2":2}
{"1":1,"fx":4,"2":2}

Howdy, Stranger!

Categories

In this Discussion

Top Posters

Datasaver module doesn't load

Comments

Howdy, Stranger!

Quick Links

Categories

In this Discussion

Top Posters

Datasaver module doesn't load

Comments