Don’t register a translation provider when no models are available

[SystemKeeper]

The translate app always registers as a translation provider, even if no models are available. This results in $this->translationManager->hasProviders() returning true, even when no provider can actually be used.
This check is used in talk since version 18 (see nextcloud/spreed#10317) and would now need a second check for the available languages to correctly show/hide the translate options on the clients.

[marcelklehr]

Why would one install this app without actually installing any models?

[SystemKeeper]

Why would one install this app without actually installing any models?

In general you won’t, I agree. But we actually had that issue on c.nc.c. Nobody noticed that the models were missing. In Talk 18 we changed the way we detect translation availability (since we only include a Boolean in the capabilities when a translation provider is registered and separately fetch the available languages).

[marcelklehr]

Nobody noticed that the models were missing.

I think this is a unique aspect of c.nc.c -- that no admin actually cares properly about the apps that are installed.

[nickvergessen]

that no admin actually cares properly about the apps that are installed.

[nickvergessen]

Why would one install this app without actually installing any models?

Maybe the model was lost on an upgrade/update of the app or something alike? Are they not stored in the apps/ folder?

If so updating the app from the appstore will remove the directory and copy the newly downloaded appstore app to the place again and the models are gone again?
https://github.com/nextcloud/server/blob/6f39d82031202a2a8d1fb81ea448a2ffdc52cc29/lib/private/Installer.php#L368-L376

[marcelklehr]

Ah, yes, that's a problem indeed. But that partly proves my point: people updated the app without checking if it still works.

[nickvergessen]

Well no one expects that updating an app would remove data? On our instance there is a cron job updating apps btw, and I guess we are not the only ones with that 🙃

But I think there was a message now telling that no models are there, or was that from another app?

Maybe sending a notification to admins could be another option? 🤔

[marcelklehr]

Well no one expects that updating an app would remove data?

Definitely. This needs to be fixed. I don't think the solution in OP is the way to go though.

But I think there was a message now telling that no models are there, or was that from another app?

The admin panel of the app shows a warning.

[nickvergessen]

The admin panel of the app shows a warning.

Maybe this can be turned into one of the new ISetupChecks? https://github.com/nextcloud/server/blob/39d2970191f88b0e9575e170e904a5c2214cb709/lib/public/SetupCheck/ISetupCheck.php#L36
But documentation is still pending, so can only send you to the code: nextcloud/server#32550 (comment)

[marcelklehr]

Oh, yeah, this is a nice idea! Thank you!