I made a little sign-up form example with React.
I built it in RequireBin. The main react model in isn’t working in RequireBin and I’m working to get it fixed. In the meantime I’ve published benatkin-react to npm which makes the minimal changes needed to get it to work (none to the code, just to the packaging).
The sign-up form I made has validation which highlights invalid fields with red after an attempt has been made to enter it in correctly.