Web/API/GlobalEventHandlers/onformdata

The onformdata property of the GlobalEventHandlers mixin is the EventHandler 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	Status	Comment
HTML Living StandardThe definition of 'onformdata' in that specification.	Living Standard

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`onformdata`	Chrome Full support 77	Edge Full support 79	Firefox Full support 72	IE No support No	Opera Full support 64	Safari No support No	WebView Android Full support 77	Chrome Android Full support 77	Firefox Android No support No	Opera Android Full support 55	Safari iOS No support No	Samsung Internet Android Full support 12.0

Legend

Full support: Full support
No support: No support