Unhandled exception thrown from getLocalStorage()

[stretch1975]

Versions (please complete the following information):

• NgxWebstorage: [3.0.2]
• Angular: [e.g. 7.2.4]

Describe the bug
Some IE 11 settings can result in an error that says, "The operations attemtped to access data outside the valid range" when trying to get the value for window.localStorage.

To Reproduce
Steps to reproduce the behavior:

1. Add ngx-webstorage to your project and browse to it in IE

Expected behavior
The exception should be caught and handled gracefully

Screenshots
The attached screenshot shows how the window.localStorage value can throw an exception and how other developers have handled it...

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Additional context
Locally if I change this code:
function getLocalStorage() {
return (typeof window !== 'undefined') ? window.localStorage : null;
}

To this:
function getLocalStorage() {
try{
return (typeof window !== 'undefined') ? window.localStorage : null;
}catch(err){
return null;
}
}

It will work

Thanks!

[bRRRITSCOLD]

This has been bugging our team for months on end too! We havent been able to pinpoint it until now.

Making the below changes, just like the OP, fixed my issues:

Source Code:

function getLocalStorage() {
  return (typeof window !== 'undefined') ? window.localStorage : null;
}

Change:

function getLocalStorage() {
  try{
    return (typeof window !== 'undefined') ? window.localStorage : null;
  } catch (err) {
    return null;
  }
}

However, I am unsure how the community would react to catching errors and always returning null, my proposed change is below:

function getLocalStorage() {
   return (typeof window !== 'undefined' && window.localStorage) ? window.localStorage : null
}

I think this could bleed over to getSessionStorage. My proposed change to that - while we are at it - would look like:

function getSessionStorage() {
   return (typeof window !== 'undefined' && window.sessionStorage) ? window.sessionStorage : null
}

Thoughts?

[PillowPillow]

Hello ! thanks for this issue.

I'm unable to test on IE till next week but the fix seems weird to me.
How the localstorage could be unavailable if window exists..? Does this issue occurs on every setups ? not just on private mode or so ?

[stretch1975]

This appears to be a common issue with IE running in protected mode. See this link for another package that dealt with the same issue: tinymce/tinymce#4338

…

Sent from my iPhone

On Jun 13, 2019, at 5:00 AM, Nicolas Gaignoux ***@***.***> wrote: Hello ! thanks for this issue. I'm unable to test on IE till next week but the fix seems weird to me. How the localstorage could be unavailable if window exists..? Does this issue occurs on every setups ? not just on private mode or so ? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[bRRRITSCOLD]

Pillow - looks like the comment in stretch's linked issue that you need to look at to recreate:

nileshbhagwat's comment on Apr 13, 2018

[psalkowski]

I have similar problem, localStorage is not always available. Some users can disable local storage (and session storage) in browser settings. In that case, the above error will be thrown.

My suggestion is to make local storage in object (key->value). It will work until user will refresh page, but should be enough.

Also, if you just use window.localStorage when it's disabled, it will thrown an exception (access denied), so, the test should be different:

try {
    window.localStorage.getItem('test');
    return window.localStorage;
} catch(ex) {
    return null;
}

Same thing for sessionStorage

[ezpar]

This issue still seems to persist even in the most current 5.0.0 version. Any chance you could implement one of the suggested solutions?

[vixriihi]

This is also still an issue in 6.0.0. This also occurs when loading a page in an iframe and when in Chrome 3rd party cookies are not allowed (seems like localstorage and sessionstorage are not available then either and throw an exception when accessed).
We had to wrap both getLocalStorage getSessionStorage with a try catch mentioned in bRRRITSCOLDs comment.