Develop Reference

submit button does not post when its attributes were changed

I am using a form and a submit button in it to call a post request to server in html
In submit button, I use onclick event to change something in UI before posting request. Everything is fine when I do not change anything to the submit button, it posts request successfully.
But if I change anything in submit button such as value, disable attribute,... then it does not post request
Here is my code
<form action="url"method="post">
<input type="submit" onclick="return onClick(event)">
</form>
js code that does not post request
function onClick(e) {
const submit = e.target // or = this
submit.value = "Clicked"
submit.disabled = true
return true
}
js code that posts request successfully
function onClick(e) {
alert("Clicked")
return true
}
Could somebody tell me the reason why it does not post successfully and how to post with UI change like above?

You need to use submit method to achieve the result.
-> Assign id to the button and form element then get the element like,
const btn = document.getElementById('btn');
const form = document.getElementById('form');
It is always recommended to use addEventListener() method in javascript instead of making it in HTML template.
form.addEventListener('submit', onSubmit)
-> Now you can change the value of an attribute in submit method like,
function onSubmit(){
btn.value = "Clicked";
btn.disabled = true;
return true
}
Working snippet as follows,
const btn = document.getElementById('btn');
const form = document.getElementById('form');
function onSubmit(){
btn.value = "Clicked";
btn.disabled = true;
return true
}
form.addEventListener('submit', onSubmit)
<form id="form" action="url" method="post">
<input type="submit" id="btn">
</form>

Whether a form sends a POST or GET request is based on its method attribute. Try changing your form to
<form action="url" method="post">
<input type="submit" onclick="return onClick(event)">
</form>

another solution from me, I found it myself and many thanks to #Maniraj Murugan for your help above: use input type="button" instead, and in onclick event, use form.submit() to submit manually
<form action="url"method="post">
<input type="button" onclick="return onClick(event)">
</form>
and in onClick event
function onSubmit(e){
const btn = e.target
btn.value = "Clicked"
btn.disabled = true
const form = document.getElementById('form')
form.submit()
}

Placeholder only appears for split second [duplicate]

I'm working on an ASP.net web application.
I have a form with a submit button. The code for the submit button looks like <input type='submit' value='submit request' onclick='btnClick();'>.
I want to write something like the following:
function btnClick() {
if (!validData())
cancelFormSubmission();
}
How do I do this?

You are better off doing...
<form onsubmit="return isValidForm()" />
If isValidForm() returns false, then your form doesn't submit.
You should also probably move your event handler from inline.
document.getElementById('my-form').onsubmit = function() {
return isValidForm();
};

Change your input to this:
<input type='submit' value='submit request' onclick='return btnClick();'>
And return false in your function
function btnClick() {
if (!validData())
return false;
}

You need to change
onclick='btnClick();'
to
onclick='return btnClick();'
and
cancelFormSubmission();
to
return false;
That said, I'd try to avoid the intrinsic event attributes in favour of unobtrusive JS with a library (such as YUI or jQuery) that has a good event handling API and tie into the event that really matters (i.e. the form's submit event instead of the button's click event).

Sometimes onsubmit wouldn't work with asp.net.
I solved it with very easy way.
if we have such a form
<form method="post" name="setting-form" >
<input type="text" id="UserName" name="UserName" value=""
placeholder="user name" >
<input type="password" id="Password" name="password" value="" placeholder="password" >
<div id="remember" class="checkbox">
<label>remember me</label>
<asp:CheckBox ID="RememberMe" runat="server" />
</div>
<input type="submit" value="login" id="login-btn"/>
</form>
You can now catch get that event before the form postback and stop it from postback and do all the ajax you want using this jquery.
$(document).ready(function () {
$("#login-btn").click(function (event) {
event.preventDefault();
alert("do what ever you want");
});
});

you should change the type from submit to button:
<input type='button' value='submit request'>
instead of
<input type='submit' value='submit request'>
you then get the name of your button in javascript and associate whatever action you want to it
var btn = document.forms["frm_name"].elements["btn_name"];
btn.onclick = function(){...};
worked for me
hope it helps.

This is a very old thread but it is sure to be noticed. Hence the note that the solutions offered are no longer up to date and that modern Javascript is much better.
<script>
document.getElementById(id of the form).addEventListener(
"submit",
function(event)
{
if(validData() === false)
{
event.preventDefault();
}
},
false
);
The form receives an event handler that monitors the submit. If the there called function validData (not shown here) returns a FALSE, calling the method PreventDefault, which suppresses the submit of the form and the browser returns to the input. Otherwise the form will be sent as usual.
P.S. This also works with the attribute onsubmit. Then the anonymus function function(event){...} must in the attribute onsubmit of the form. This is not really modern and you can only work with one event handler for submit. But you don't have to create an extra javascript. In addition, it can be specified directly in the source code as an attribute of the form and there is no need to wait until the form is integrated in the DOM.

You need to return false;:
<input type='submit' value='submit request' onclick='return btnClick();' />
function btnClick() {
return validData();
}

With JQuery is even more simple: works in Asp.Net MVC and Asp.Core
<script>
$('#btnSubmit').on('click', function () {
if (ValidData) {
return true; //submit the form
}
else {
return false; //cancel the submit
}
});
</script>

Why not change the submit button to a regular button, and on the click event, submit your form if it passes your validation tests?
e.g
<input type='button' value='submit request' onclick='btnClick();'>
function btnClick() {
if (validData())
document.myform.submit();
}

You need onSubmit. Not onClick otherwise someone can just press enter and it will bypass your validation. As for canceling. you need to return false. Here's the code:
<form onSubmit="return btnClick()">
<input type='submit' value='submit request'>
function btnClick() {
if (!validData()) return false;
}
Edit onSubmit belongs in the form tag.

It's simple, just return false;
The below code goes within the onclick of the submit button using jquery..
if(conditionsNotmet)
{
return false;
}

use onclick='return btnClick();'
and
function btnClick() {
return validData();
}

function btnClick() {
return validData();
}

<input type='button' onclick='buttonClick()' />
<script>
function buttonClick(){
//Validate Here
document.getElementsByTagName('form')[0].submit();
}
</script>

Clicking on form button without an <input>?

I am trying to click on the "Slow Download" button on this page, where the html is
<form action="https://nitroflare.com/view/A71F0994E20F2E0/security-privacy.jpg" method="post">
<button id="slow-download" class="bootstrapButton" name="goToFreePage">Slow Download</button>
</form>
where I am doing
$( document ).ready(function() {
function startFreeDownload(){
getElementsById('slow-download')[0].submit();​
};
startFreeDownload();
});
All the posts I have seen have <input ... > which this one doesn't.
Question
Can someone tell me what I am doing wrong?

This solved the problem.
function SkipId(objId){
var oId = document.getElementById(objId);
oId.click();
}
window.onload = function(){
SkipId('slow-download');
};

You are trying to submit a button, but should submit a form instead:
...
getElementsById('slow-download').parent()[0].submit();​
...

Get a submitted form value using jQuery, have more than 1 form with the same class name

I've tried to search for an answer here but there are no answers that match what I need. I have more than 1 form with class name .sbt-form:
<form class='sbt-form'>
<input name='kord' val=1/>
</form>
<form class='sbt-form'>
<input name='kord' val=2/>
</form>
<form class='sbt-form'>
<input name='kord' val=3/>
</form>
When one form is submitted (let's say the third one) I want just to get the value of input element with name = 'kord'
How do i do this using jQuery?

You can attach a submit handler to the forms and search within them for the element you want to find. Try this:
$('.sbt-form').submit(function(e) {
e.preventDefault(); // stop the form submission to the server. Comment this if not needed.
var inputValue = $(this).find('input[name=kord]').val();
});

Try this :
$("mySubmitButton").click(function () {
$(this).closest(".sbt-form").find("input[name='kord']").val();
});

try
$('.sbt-form').click(function() {
$(this).find("input[name='kord']").val();
});

OR you can get whole form's value with serialize() function on submitting the form:
JS Code:
$(".sbt-form").submit(function(e){
e.preventDefault();
console.log($(this).serialize());
});

How to submit three forms with one submit button

I have 3 forms I would like to submit with one button:
<form id="#formEditUsername">
//Code
</form>
<form id="#formEdituseremail">
//Code
</form>
<form id="#new_password_form">
//Code
</from>
<button type="submit" class="btn btn-success" id="btnUpdate">Save</button>
I understand that the best way to do this is probably Ajax, but am unsure how I would do this; create two AJAX functions for the first two forms and then call the functions when the third is submitted?

Try this
$(document).ready(function() {
$("#btnUpdate").click(function() {
$.post($("#formEditUsername").attr("action"), $("#formEditUsername").serialize(),
function() {
$.post($("#formEdituseremail").attr("action"), $("#formEdituseremail").serialize(),
function() {
$.post($("#new_password_form").attr("action"), $("#new_password_form").serialize(),
function() {
alert('All forms submitted');
});
});
});
});
});

As #Jari mentioned, you can simply collect data from first two forms and submit them all together.
Note: this aproach requires input name attributes to be unique among all three forms.
Simple example of AJAX call:
var firstFormData = $("#formEditUsername").serialize();
var secondFormData = $("#formEdituseremail").serialize();
var thirdFormData = $("#new_password_form").serialize();
$.post(
URL, // target URL of your choice
firstFormData + secondFormData + thirdFormData
);

<form id="#formEditUsername" class="frmToSubmit" method="post">
//Code
</form>
<form id="#formEdituseremail" class="frmToSubmit" method="post">
//Code
<form>
<form id="#new_password_form" class="frmToSubmit" method="post">
//Code
</from>
<script type="text/javascript">
$(document).ready(function() {
$("#btnUpdate").click(function() {
$(".frmToSubmit").submit();
});
});
</script>