FormData的submitter參數

簡單來說

1. button可以攜帶value值，並且在點擊button時候，form提交會帶上button的value

<button name="foo" value="bar" type="submit">Submit</button>

2. button帶值可以有多個

<form action="/test-form" method="post">
    <button name="_action" value="delete" type="submit">Delete</button>
    <button name="_action" value="disable" type="submit">Disable</button>
</form>

3. 直接 new FormdData 不會攜帶button的value

const formdata = new FormData(form);

4. 使用 submitter 參數，可以指定提交某個button的value

form.addEventListener("submit", function (event) {
    event.preventDefault();
    const formdata = new FormData(form, event.submitter);
});

 

 

具體可參考 The submitter parameter for FormData