[Vaadin 19] Custom offline page is not used when navigating to Java views

Description of the bug / feature

I’ve prepared my custom offline.html page. I’ve put it in 3 places in my project (java + spring app on Vaadin 19):

1. src/main/resources/META-INF/resources/ (according to https://vaadin.com/docs-beta/latest/guide/configuration/pwa/#offlinePath)
2. even in src/main/webapp/ (because the above didn’t work)
3. even in frontend/ (where index.html resides successfully)

Of course I have this @PWA(... , offlinePath = "offline.html") in my AppShellConfigurator class.

But when I’m testing offline mode (Chrome / Network / Offline ) my custom offline.html page is not show only Vaadin default one is shown:

Expected behavior

I want my custom offline page to be shown. Is this a bug or I’m doing something wrong?

Versions:

- Vaadin / Flow version: Vaadin 19.0.0.beta4
- Java version: 8
- OS version: Win10
- Browser version (if applicable): Chrome

[joheriks]

Decided on a solution were the custom offline page is used in both cases (stand-alone and embedded in the app shell protected by an <iframe>). So the behavior will be:

Offline start:

• offlinePath=custom.html: render custom.html as a single page in browser
• No custom offlinePath set: render app shell with the Flow default offline page in iframe

Offline navigation:

• offlinePath=custom.html: render appshell with custom.html embedded in iframe
• no custom offlinePath set: render appshell with the Flow default offline page in iframe

Currently blocked by vaadin/flow#10031

[darmro]

Hi @Haprog I have only java views (no TS, so far). Plus static html page (static and closed - I mean seperated from views, theme, styles) called offline.html. I thought that if I give it to offlinePath my static html page is shown, but no, only vaadin default page is shown, moreover in English of course- it is a problem, cause it should be in Polish 😃
If it was possible to parametrize this default offline page and give your texts it wolud be enough. For example via CustomizedSystemMessages, where I can set my texts for eg. session expiration, or in the same way as I configure reconnect text (via dedicated ReconnectDialogConfiguration class).