[whatwg] question about the input tag attributes

[Nicola Di Fabrizio]

Good day everyone,
I have a question about the new input tag attributes.

is it possible to set a attribute for checking the element
if it is not empty

like
<input type="text" needed="yes">

if needed = yes and the element has no value
then appears a msgbox like
"Please input something..."

or the msgbox text is also an attribute
where you can put in your own message.

what you think about the idea?
are there any discussion about something like this?

Many thanks and best wishes from Germany

nicola di fabrizio