Develop Reference

empty check for multiple form in a page separately

I have two forms (consist with input,textarea,checkbox) in a page. I want check emptiness of these forms separately on click seperate button.
I use the following script. But it shows empty message if any of these form input is empty.
$('#submit').click(function(e) {
var empty = false;
$('input, textarea').each(function() {
if ($(this).val() == '') {
empty = true;
}
});
if (empty) {
alert("empty");
e.preventDefault();
}
else {
document.getElementById("contact").submit();
}
})()

Never assign stuff to submit buttons
Do not submit a form from a submit button if you have chosen to use preventDefault if something wrong. It could submit the form twice
$(function() {
// on the submit event NOT the button click
$('form').on("submit", function(e) { // any form - use .formClass if necessary to specific forms
var empty = false;
$("input, textarea", this).each(function() { // this form's inputs incl submit
if ($.trim($(this).val()) == "") { // trim it too
console.log(this.name,"empty")
empty = true;
return false; // no need to continue
}
});
if (empty) {
alert(this.id + " is empty"); // or set a class on the div
e.preventDefault(); // cancel submission
}
});
});
div {
border: 1px solid black;
width:500px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<form id="form1">
<div>
<input type="text" value="" name="field1" /><br/>
<textarea name="field2"></textarea><br/>
<input type="submit" value="Submit" />
</div>
</form>
<hr/>
<form id="form2">
<div>
<input type="text" value="" name="field3" /><br/>
<textarea name="field4"></textarea><br/>
<input type="submit" value="Submit" />
</div>
</form>
You could also add required to the fields

You need to restrain the handler to the form containing the clicked button:
$('#submit').click(function(e) {
var form = $(this).parents('form:first');
var empty = false;
$('input, textarea', form).each(function() {
// the rest is the same
I'd also like to point out that you cannot have the same ID on multiple controls, so
$('#submit')
should always return exactly one button. You should do something like this, where you distinguish the buttons by class instead:
<input type="submit" id="submitA" class="submitButton">
<input type="submit" id="submitB" class="submitButton">
and select with
$('.submitButton')

you know you can also use jquery to reset the form like so
form.resetForm();

Submit form only when submit button clicked and prevent "Enter" submitting form

I want to stop a user submitting a form upon clicking enter.
This works for that
$(document).ready(function() {
$(window).keydown(function(event){
if(event.keyCode == 13) {
event.preventDefault();
return false;
}
});
});
However I have other buttons on the page that when I tab to and click enter to avail of their functionality, this is blocked via this function.
The button sits as so:
<input type='button' tabindex="29" value='Add Additional Drug' id='addButton'>
And I only want to submit the form when enter pressed while my submit button is selected.
<input type="submit" name="submit" value="Submit" tabindex="40" class="submit"/>
How would I do this?
EDIT
I see the answer in the attached Stackoverflow but he allow people to press Enter if they have completed all the fields:
I don't want a user to press Enter unless they have a button selected(i.e. Can't press Enter, tab to button, can press enter, which will trigger the button to do its functionality and not submit the form.
The form works on a Tabbing basis, so a user will tab over all the fields.

Binding the keydown event to the whole document will affect all inputs and forms on the page, you may have several ones in your page so it will mess up the whole page logic.
You can bind it to a specific form instead:
$("#myForm input").not("#addButton").keydown(function(event) {
if (event.keyCode == 13) {
event.preventDefault();
return false;
}
});
Demo:
$("#myForm input").not("#addButton").keydown(function(event) {
if (event.keyCode == 13) {
event.preventDefault();
return false;
}
});
form input {
display: block;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form action="" id="myForm">
<input type="text" name="input1" />
<input type="text" name="input2" />
<input type="text" name="input3" />
<input type="submit" name="submit" value="Submit" tabindex="3" class="submit" />
</form>
Note:
I used #myForm as test id here to target a specific form in the
page, you just need to use your form id.
Using jQuery .not() method in .not("#addButton") won't affect the button with id="addButton".

First, keep in mind that what you are attempting breaks UI accessibility standards.
Bearing this in mind, you'll need to stop using a true "submit" button and use a regular button that impersonates the submit button.
Next, you'll need to manually trigger the click events for all non-submit button buttons via code.
Here's a working example. See the comments for details:
$(document).ready(function() {
$(window).on("keydown", function(event){
// Check to see if ENTER was pressed and the submit button was active or not
if(event.keyCode === 13 && event.target === document.getElementById("btnSubmit")) {
// It was, so submit the form
document.querySelector("form").submit();
} else if(event.keyCode === 13 && event.target !== document.getElementById("btnSubmit") ){
// ENTER was pressed, but not while the submit button was active
alert("Enter pressed on something other than submit button.");
// Cancel form's submit event
event.preventDefault();
// Invoke click event of target so that non-form submit behaviors will work
event.target.click();
// Tell JQuery to cancel the event
return false;
}
});
// Non-submit button event handling
$("#btnOther").on("click", function(){
alert("Other button clicked!");
});
// Set up your "regular" button to act as a "submit" button when it is clicked
$("#btnSubmit").on("click", function(){
// Submit the form
document.querySelector("form").submit();
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form action=# method=post>
<input name=test>
<input type=button id="btnOther" value="Other Button">
<input type=button id="btnSubmit" value=Submit>
</form>

Enter key doesn't activate button

I have a form with one field that the user needs to type into, and a button underneath that when clicked, does some jQuery and hides the login-form. But when I hit enter after typing something in, the page refreshes...
There's part of me that thinks it doesn't need to be an <input> or a <form>
I don't actually need to post anything. I have tried changing the input to a <button> which completely ruins my styling and still doesn't work. What's the best way of getting round this?
<div class="login-page">
<div class="form">
<form class="login-form" method="POST">
<!-- user inputs -->
<p class="phc">PHC:</p><input type="text" id="username" placeholder="Enter Your PHC Here" />
<!-- your submit button -->
<input class="login" type="button" id="submit" value="login">
</div>

True, Adam. If the form does not contain the type submit button, a keypress event has to be added manually. Otherwise Enter will act as the Accept Button on the form.

You need to attach keypress event to the form or at least the field. For convenience, you also need to combine the callback functions into one.
$('#username').on('keypress', function(event){
var code = event.keyCode || event.which;
if(code == 13){
// submit the form.
}
});
$('#username').on('keypress', function(event){
var code = event.keyCode || event.which;
if(code == 13){
console.log('Submitting form');
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form class="login-form" method="POST">
<p class="phc">PHC:</p><input type="text" id="username" placeholder="Enter Your PHC Here" />
<input class="login" type="button" id="submit" value="login">
</form>

If the enter key is pressed when focused to an input field inside a form that has a submit button, the default browser behaviour is to fire a submit event on that form. You can prevent this happening by either:
return false;
or
e.preventDefault();
Full code:
$('.login-form').on('submit', function() {
return false;
});
Fiddle: https://jsfiddle.net/nc1e2gm6/
Bear in mind that if you go down the route of using e.preventDefault(); instead or return false;, you need to pass the e variable from the function call, like:
$('.login-form').on('submit', function(e) { ...

Don't think i explained it very well but i have fixed it, the enter key now activates the submit button rather than refresh the page.
$("form").submit(function() { return false; });
$(document).ready(function(){
$('#username').keypress(function(e){
if(e.keyCode==13)
$('#submit').click();
});
});

Find all submit buttons of submitted form

I'm trying to disable all submit type elements of a form once it's submitted, to avoid double clicking. But I only want the buttons within the submitted form to be disabled.
For example when clicking the Submit button, only the Submit button and the Another submit to disable (same form) should be disabled. The other submit elements should remain as they were.
The code below disables all submit elements.
$(document).on('submit', function (event) {
event.preventDefault();
var submit_button = $(':submit');
submit_button.prop('disabled', true);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button type="submit">Not part of submitted form (leave enabled)</button>
<form>
<input type="text">
<button type="submit">Part of another Form (leave enabled)</button>
</form>
<form>
<input type="text">
<button type="submit">Submit</button>
<button type="submit">Another submit to disable (same form)</button>
</form>

Well, event.target will refer to the submited form, so you can find all submit buttons inside that form using the :submit selector:
$(document).on('submit', function (event) {
event.preventDefault();
$(':submit',event.target).prop('disabled', true);
});
Check the below snippet example
$(document).on('submit', function(event) {
event.preventDefault();
$(':submit', event.target).prop('disabled', true);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button type="submit">Not part of submitted form (leave enabled)</button>
<form>
<input type="text">
<button type="submit">Part of another Form (leave enabled)</button>
</form>
<form>
<input type="text">
<button type="submit">Submit</button>
<button type="submit">Another submit to disable (same form)</button>
</form>

Detect on form submit then search for the button[type=submit] in that form and disable them.
$('form').on('submit', function (event) {
event.preventDefault();
var submit_button = $(this).find('button[type="submit"]');
submit_button.prop('disabled', true);
});

Controlling ENTER key

How can we make a form in a page doesn't submit on pressing Enter — rather. it does the same work as pressing a particular button or icon or image?
Here are the contents of my form:
<input type="text" id="txt" /><input type="button" value="search"
onclick="searchresult()" />
The problem is that if I press Enter, the form submits and text field clears itself but the function searchresult() doesn't show its effect. When only pressing the button, it works well.

HTML
<input type="text" id="txt"/>
<input type="button" value="search"/>
jQuery
$('input[type=text]').on('keyup', function(e) {
if(e.which == 13) { // 13 is keycode for enter
e.preventDefault();
}
})
You can also bind to submit() like following
$('form').submit(function(e) { // instead of only `form`,
// use with `id` or `class` combination
if(e.which == 13) {
e.preventDefault();
}
});
Remainder
Don't forget to place you code within
$(document).ready(function() {
// your code
});
in short
$(function() {
// your code
});

Alternatively, instead of disabling the enter key, you might be able to bind to the onsubmit event to perform any processing prior to submitting the form. From the MDN documentation:
The submit event is raised when the user clicks a submit button in a form ().

Try:
$('form').submit(function(event){
if(!$(':focus',this).is(':button'))
event.preventDefault();
});
This attaches to the form itself. If it was submitted any way other that clicking the submit button it halts the submission process. For better performance narrow down the 'form' selector.

Try this:
form
<form id="myForm">
<input type="text" id="txt" />
<input type="submit" value="search" />
</form>
js
<script>
$(document).ready(function(){
$("#myForm").submit(function(e){
e.preventDefault();
searchresult();
});
});
</script>