My save creator keeps erroring

[plas]

Godot Version

4.4.1

Question

` I’m trying to make a save and it keeps going “Attempt to call store_string on null instance”. How do I… not have it do that? My code for the control is:
extends Control

func _on_font_pressed():
$ProgressBar.value = 6
$fontquest.hide()
$font.hide()
$fontyes.hide()
$SetupText2.hide()
$SetupText.show()
$tosquest.show()
$tos.show()
$tosyes.show()
$tosno.show()

func _on_tosyes_pressed():
$ProgressBar.value = 14
$tosquest.hide()
$tos.hide()
$tosyes.hide()
$tosno.hide()
$toswhy.hide()
$namequest.show()
$name.show()
$nameyes.show()

func on_name_pressed():
$ProgressBar.value = 26
global.username = $name.text
$namequest.hide()
$name.hide()
$nameyes.hide()
$passquest.show()
$pass.show()
$passyes.show()

func on_passyes_pressed():
$ProgressBar.value = 40
global.password = $pass.text
$passquest.hide()
$pass.hide()
$passyes.hide()
$payquest.show()
$pay.show()
$payyes.show()

func on_payyes_pressed():
$ProgressBar.value = 50
$payquest.hide()
$pay.hide()
$payyes.hide()
$funny1.show()
await get_tree().create_timer(1.7).timeout
$ProgressBar.value = 55
$funny1.hide()
$funny2.show()
await get_tree().create_timer(0.6).timeout
$ProgressBar.value = 67
$funny2.hide()
$funny3.show()
var usr1 = DirAccess.open(“user://”)
usr1.make_dir(“Glass 10”)
var usr = DirAccess.open(“user://Glass 10”)
global.userdat = FileAccess.open(“user://Glass 10/user_data.dat”, FileAccess.READ_WRITE)
global.userdat.store_string(global.username+“\n”+global.password+“\n”) # it errors here
usr.make_dir(“apps”)

func _on_tos_close_requested():
$toswhy.show()

func _process(_delta):
if “\n” in $name.text:
$name.text = $name.text.replace(“\n”, “”)
on_name_pressed()
elif “\n” in $pass.text:
$pass.text = $pass.text.replace(“\n”, “”)
on_passyes_pressed()
elif “\n” in $pay.text:
$pay.text = $pay.text.replace(“\n”, “”)
on_payyes_pressed()
var original_text = $pay.text
var filtered_text = “”
for char in original_text:
if char in “0123456789”:
filtered_text += char
$pay.text = filtered_text
and my global code is
extends Node

var username = “defaultname”
var password = “defaultpass”
var grade = “a”
var ran = “0”
var ads = “0”
var fight = “0”
var userdat = FileAccess.open(“user://Glass 10/user_data.dat”, FileAccess.READ_WRITE)
`

[hexgrid]

Posting your code in backticks makes it easier to read:

```gdscript
code
code
code
```

Looks like:

code
code
code

global.userdat = FileAccess.open(“user://Glass 10/user_data.dat”, FileAccess.READ_WRITE)
global.userdat.store_string(global.username+“\n”+global.password+“\n”) # it errors here

I imagine what’s happening is that FIleAccess.open() is returning null and so attempts to store_string() with the result are blowing up.

I’d advise something like:

    var usr1 = DirAccess.open(“user://”)

    if !usr1:
        print("Drat, couldn't open user dir: " + DirAccess.get_open_error())
        return

    var err = usr1.make_dir(“Glass 10”)

    if err != Ok:
        print("Curses, couldn't make dir: " + str(err))

    # You don't need to open the directory to read files, btw...

    var usr = DirAccess.open(“user://Glass 10”)

    if usr == null:
        print("Fiddlesticks, couldn't open Glass 10: " + DirAccess.get_open_error())
        return

    var path = “user://Glass 10/user_data.dat”

    global.userdat = FileAccess.open(path, FileAccess.READ_WRITE)

    if !global.userdat:
        print("Bother, couldn't open " + path + " -> " + FileAccess.get_open_error())
        return

    if !global.userdat.store_string(global.username+“\n”+global.password+“\n”):
        print("Vexing, couldn't store a string: " + str(global.userdat.get_error()))

In general, you need to check every filesystem access for errors. Even if you’re absolutely certain the code is bug-free, you can run into exceptional circumstances like “the computer is out of disk space” which mean that your filesystem request fails.