How to handle authentication when user is offline using Angular PWA?

[jalchr]

This question is posted on Stack OverFlow
I have an angular application with PWA. My main concern is to allow the user to use the app while offline without internet connection. The question is: how can I accomplish that with IdentityServer and OIDC ? I'm considering the following solution: Assuming I have a valid "Refresh Token", then as long as the internet connection is offline, I would consider the user as still authenticated. Of course, this means the user has already logged in while "online".
If I have a Refresh Token, then I can assume I have "valid" credentials. As long as I'm still "disconnected" from the internet (which could be for hours) , and there is no way to "reevaluate" the validity, I can assume I'm "OKAY". When connection is back, and before submitting all data changes, I'll use the refresh token to request a new "access token" and resume work normally. The question is, does angular-oauth2-oidc library has any built in support for such functionality, or it just works on "expiry dates" and timers .

Any suggestions for handling "login" while still "offline". For example, Windows OS uses some kind of "local storage" to authentication users, even while they have no internet connection. Any suggestions, appreciated

[jalchr]

Once the IdentityServer is unreachable, due to "Offline" or other issues, I noticed the following:

Tracing back to this line of code:

Due to the 'src' is unreachable, the iframe creation fails and hence to the whole "silent refresh" process. When back online, the silent refresh process can't detect that by itself.

[jeroenheijmans]

This seems like a bug/omission to me. To summarize/paraphrase the bug:

If the app loads while the IDS is unreachable, the setup of silent refresh (e.g. creating the iframe) will fail because the page in the hidden iframe can't be loaded, and the app will never recover from this.

A solution would be for the library to check for load failures in the iframe, and possibly retry (or publish an event about the failure, and allow the user of the library to choose when to retry).

[jalchr]

Yes, a retry mechanism is needed.

[dome4]

Have there been any updates on this? Would be a helpful feature 😃