I want to implement the below simple JavaScript function submitForm() based on XMLHttpRequest and FormData. This functions works well on the first <form> but fails on the second one: the function should use input.formaction instead of form.action.
How to detect the pressed <input> and retrieve the corresponding formaction?
( Most of SO answers advise to use a framework (as jquery) for such processing. But I think learning solely pure JavaScript is easier than learning also JS frameworks. If you are convinced that this snippet can be written simpler using a framework, please propose your version. Please explain also why your advised framework is pertinent/relevant/suitable in this case. I may decide to learn your favorite JS framework... EDIT: I have found this similar question: JQuery get formaction and formmethod )
<!DOCTYPE html>
<html>
<head>
<script>
function submitForm(form)
{
var xhr = new XMLHttpRequest();
xhr.onload = function() { alert (xhr.responseText); }
xhr.open ("post", form.action, true);
xhr.send (new FormData (form));
return false;
}
</script>
</head>
<body>
<form action="first.php" onsubmit="submitForm(this);">
<fieldset>
<legend>First</legend>
<input type="text" name="data" />
<input type="submit" />
</fieldset>
</form>
<form onsubmit="submitForm(this);">
<fieldset>
<legend>Second</legend>
<input type="text" name="data" />
<input type="submit" value="A" formaction="second-A.php" />
<input type="submit" value="B" formaction="second-B.php" />
</fieldset>
</form>
</body>
</html>
( I have implemented this snippet after reading XMLHttpRequest to Post HTML Form, Sending POST data with a XMLHttpRequest and the excellent MDN documentation. )
I'd propose to set the event listener in JavaScript, so you can access the Event object.
function submitForm(e) {
// Get the DOM element that submitted the form
var caller = e.target || e.srcElement;
// Set the action to 'formaction' attribute of the caller if it exists, otherwise use the action of the form the caller is in
var action = caller.getAttribute("formaction") || caller.form.action;
// This is your code, I just changed the variable name for the action to 'action'.
var xhr = new XMLHttpRequest();
xhr.onload = function() { alert (xhr.responseText); }
xhr.open ("post", action, true);
xhr.send (new FormData (form));
}
// Get all forms
var forms = document.querySelectorAll("form");
// Iterate over the forms
for (var i = 0; i < forms.length; ++i) {
// Set the event listener
forms.item(i).onsubmit = submitForm;
}