I just find out that I have published a form without attachment. I will suggest it will be good to have an alert prompt or notification to be in placed to avoid such incidence.
ODK Central currently does not have a built-in feature that automatically alerts users about missing attachments when publishing a form.
I agree that adding such a feature would be very useful. In the meantime, I make sure to double-check my forms to ensure I haven't missed any attachments.
If the form causes Central to list the required attachments for upload, it does give you a message when you attempt to publish if they are not all present. It's not a block (good, as some forms may have a large possible number of attachments but you only need to provide a subset) but does warn before you publish:
I didn't notice this. Thanks.
We have some work coming up to move the draft functionality to a new navigation tab (at the same level as form settings, etc). In that context, it will all be on the same page and will hopefully be easier to scan and take action on. We'll also try to make this warning stand out a bit more.
We shared a preview of this work in the last Insiders call and will solicit more feedback as it gets closer to implementation!