feat(form): deprecated and rename empty to notEmpty rule

[lubber-de]

Description

This PR renames the empty rule to notEmpy but keeps the empty rule working for backward compatibility, so people can just upgrade their code for while. A console warning will tell them about.
Reasons for renaming is that the code actually checks if a field is not empty. More explanation inside the related issue

Closes

#2937

[prudho]

LGTM

[bedengler]

Does that mean in future versions, if we are looking for en empty entry, we have to say "not[notEmpty]"?
I'd prefer keeping empty, but doing exactly what it means and if we look for not Empty, we just do a "not[empty]"....

[mvorisek]

Does that mean in future versions, if we are looking for en empty entry, we have to say "not[notEmpty]"? I'd prefer keeping empty, but doing exactly what it means and if we look for not Empty, we just do a "not[empty]"....

I would be fine with required, but inverting a meaning would be the worst thing possible, as not all devs read all changelogs.

[lubber-de]

Infact the not rule does not even work this way as it only accepts a string for comparison instead of another rulename.

not[empty] would currently check if the input value String isn't equal to the string "empty"

Of course we could implement supporting this, but In case someone really wants to check for a string "empty" and a rule with the same name exists would then break/ not work again. It might als isn't trivial as we would need to support something like not[max[6]] where you could simply do min[7] instead.

So existing code simply needs to be updated from empty to notEmpty.

[bedengler]

Interesting and weird.

How do you check for an empty entry then? Using "min[1]"?

What about implementing a "notrule" or some characters that signal, we are looking not for a string, but another rule?
Something like "not[empty]" looking for the string "empty" and "not[{notEmpty}]" or "notrule[notEmpty]"?

[lubber-de]

How do you check for an empty entry then? Using "min[1]"?

You can use

maxLength[0] or is[] to accomplish this

What about implementing a "notrule" or some characters that signal, we are looking not for a string, but another rule? Something like "not[empty]" looking for the string "empty" and "not[{notEmpty}]" or "notrule[notEmpty]"?

TBH, this gets complicated and all the existing rules have opposite versions already to accomplish such checks.
In doubt you can always create a custom rule

[lubber-de]

Docs added by fomantic/Fomantic-UI-Docs#483