Greetings,

I ran into a specific use case where a single page application was submitting a form to a REST API without a submit button via an HTTP PATCH method. I had read somewhere (probably StackOverflow) thathandleRequest() handles partial updates since Symfony 2.x, but since there wasn't a submit button,handleRequest() wouldn't submit the form.

Long story short, I wasn't able to find documentation regarding a solution until I saw the API for thesubmit() function with the optional$clearMissing parameter. I'm willing to submit a PR with this use case highlighting the ability to do partial updates via thesubmit() function if it sounds useful to anyone else.