GlobalEventHandlers.onformdata
The onformdata
property of the
GlobalEventHandlers
mixin is the event handler for
processing formdata
events, fired after the entry list representing the
form's data is constructed. This happens when the form is submitted, but can also be
triggered by the invocation of a FormData()
constructor. onformdata
is available on HTMLFormElement
.
Syntax
target.onformdata = functionRef;
Value
functionRef
is a function name or a function
expression. The function receives a FormDataEvent
object as its
sole argument.
Examples
// grab reference to form
const formElem = document.querySelector('form');
// submit handler
formElem.addEventListener('submit', (e) => {
// on form submission, prevent default
e.preventDefault();
// construct a FormData object, which fires the formdata event
new FormData(formElem);
});
// formdata handler to retrieve data
formElem.onformdata = (e) => {
console.log('formdata fired');
// Get the form data from the event object
let data = e.formData;
for (var value of data.values()) {
console.log(value);
}
// submit the data via XHR
var request = new XMLHttpRequest();
request.open("POST", "/formHandler");
request.send(data);
};
Specifications
Specification |
---|
HTML Standard # handler-onformdata |
Browser compatibility
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