Logic of creating FormData from submission is missing submitter handling

[pawelblaszczyk5]

Please provide the environment you discovered this bug in.

I've actually just discovered it via looking through the code after seeing announcement of 1.10 release on Twitter haha. Pardon not providing reproduction, but I can pinpoint exact lines and so I hope that's fine too 😄

Which area/package is the issue in?

router

Description

Currently FormData (and the form method/action) is just created from the event.target on form submission event. However, if form is submitted via button/input with button/image type it can carry additional information and e.g. override form action itself.

Here's an example code from React Router that does similar thing. As you can see it uses the submitter property from event to carry additional info for submission.

Btw. I've tried to look through the code and it seems like the action prop isn't doing anything currently? 😄

Please provide the exception or error you saw

Not really an error, but the form won't correctly submit the whole data

Other information

n/a

I would be willing to submit a PR to fix this issue

• Yes
• No

[brandonroberts]

Thanks @pawelblaszczyk5 if you could include some example HTML of what this looks like that would help.

[pawelblaszczyk5]

Yeah, sure 😃

  <form action="/" method="post">
    <button name="additional_value_key" value="foo">Submit with additional value</button>
    <button formaction="/different-url">Override URL</button>
    <button formmethod="get">Override method</button>
  </form>

1. button would send additional value for submission (people often use different buttons to trigger slightly different actions)
2. button would change the action where form is submitted
3. button would override the method form submission uses