Clearing Storage produces odd error message

[Apotischman]

Describe the bug When a user clicks "Clear Storage" and clicks "Delete All", the page refreshes with a cryptic error message

To Reproduce

1. Cache an offline form
2. Go offline
3. Fill out a form and submit
4. Click "Clear Storage"
5. Click "Delete All"
6. Notice the following error message appears

Expected behavior The user should be brought to a screen that says "This form is no longer available."

[MartijnR]

Something odd in the steps above. I would expect any 'Failed to fetch' error message to be shown after going back online first. I see this when following the steps (which is great):

Also it may not be realistic for a user to clear storage whilst offline, because any submission problems would probably be seen whilst online.

• [x] reproduce with single Enketo offline-capable tab: I cannot, neither online nor offline.
• [x] reproduce with multiple Enketo offline-capable tabs: I cannot, I just notice there is no automatic page refresh (but that's acceptable since we warn about that)

I'm noticing that the form does not always refresh. This may only be the case if multiple Enketo offline-capable tabs were open. This is not the reported issue though.

[Apotischman]

I was just able to reproduce this on my phone when not connected. See my recent email with a URL to try out. I saved the link to the form entry page, went offline and tried accessing. I still get the fail to fetch message instead of "no internet"

[MartijnR]

I am now able to reproduce it. I had to turn off some dev settings related to Service Workers (i.e. the cached application). No need to submit a record first.

The cached app tries to load a form but fails to fetch it.

• [x] enketo/enketo-express PR to change that message to something like "Failed to download form" or some similar string we already have. - https://github.com/enketo/enketo-express/pull/421
• [x] wait for next version of enketo-express

[MartijnR]

The user should be brought to a screen that says "This form is no longer available."

@Apotischman, this text string will be added to enketo/enketo-express and I'm trying to get it right before triggering translation update requests. You could override it in this fork, but it's nice if you don't have to.

I think "This form is no longer available" is confusing since this happens when the user is offline (and there may some other obscure conditions under which it occurs). We have a separate case for a form that is no longer available on the server (with its own message). I propose to use "Failed to download form" in this case. What do you think?

[Apotischman]

"Failed to download form" works for us. Thanks!