Form validation with Javascript function - javascript

I am trying to validate a form, to make sure that the user inputs a value into a textbox. Here's my Javascript:
var formValidation = function(a) {
if (document.getElementById(a).value == "") {
alert('Please fill out the ' + a + ' field');
return false;
}
else {
return true;
}
}
And here's the form:
<div id="cultdiv">
<form action="add.php" method="POST">
<span><input type="hidden" name="id" id="cultid"/>
<input type="text" onSubmit ="formValidation('culture')" name="name" id="culture"/>
<input type="hidden" name="type" value="culture" />
<input type="submit" value="add/update" /></span>
</form>
</div>
For some reason it doesn't stop the form from being submitted or give the alert message.

You forgot to return from your inline handler.
Also, <input>s don't have an onsubmit event; you probably meant to put that in the <form>.

slaks means something along these lines.
<script>
var formValidation = function() {
if (document.getElementById('culture').value == "") {
alert('Please fill out the culture field');
return false;
}
else {
return true;
}
}
<div id="cultdiv">
<form action="add.php" method="POST" onsubmit="return formValidation(this)">
<span><input type="hidden" name="id" id="cultid"/>
<input type="text" name="name" id="culture"/>
<input type="hidden" name="type" value="culture" />
<input type="submit" value="add/update" /></span>
</form>
</div>

Related

Using JavaScript to check for user-input

I'm submitting a form with input text to my server through my web client. What I'm trying to do is to check whether the user has passed in text into the input field before sending the form by hitting the submit button.
What I have tried so far:
var form = document.getElementById("id");
document.getElementById("id").addEventListener("click", function() {
var input = document.getElementById("content").value;
if (input == "") {
alert("write something in the textfield");
} else {
form.submit();
}
});
<form action="" method="post" id="id">
<input type="text" name="name" id="content">
<button type="submit" id="submit-id">submit text</button>
</form>
Any good tips on how to do this?
You want preventDefault on the submit event
document.getElementById("id").addEventListener("submit", function(e) {
const input = document.getElementById("content").value;
if (input.trim() === "") {
alert("write something in the textfield");
e.preventDefault()
}
});
<form action="" method="post" id="id">
<input type="text" name="name" id="content">
<button type="submit" id="submit-id">submit text</button>
</form>
Alternatively just add required attribute - no need for script:
<form action="" method="post" id="id">
<input type="text" name="name" id="content" required>
<button type="submit" id="submit-id">submit text</button>
</form>
you can use the simple code snippet instead :
<form action="" method="post" id="id">
<input type="text" name="name" id="content" required>
<button type="submit" id="submit-id">submit text</button>
</form>
function submitIt(e) {
var formData = new FormData(e);
var object = {};
formData.forEach(function(value, key) {
object[key] = value;
});
if (object.name == "") {
alert("null");
} else {
alert("ok");
return true;
}
return false;
}
<form onsubmit="return submitIt(this)">
<input type="text" name="name">
<button>submit text</button>
</form>

Show alert (Text Field is empty) on submit Html/JavaScript

How to get an Alert on Submit when I left a TextBox empty And It Should Turn To the Next page on submit.
Must Reply,
Thank You.
You can try this :
HTML :
<form action="" method="POST" id="myForm">
<input id="myInput" type="text" />
<input type="submit" />
</form>
(Replace the action attribute by the url of your destination page, the one you call the "next page").
JS (without jQuery):
var myForm = document.querySelector('#myForm');
var myInput = document.querySelector('#myInput');
myForm.addEventListener('submit', function(pEvent) {
if(myInput.value === '') {
pEvent.preventDefault(); //Prevents the form to be sent
alert('Ho! Stop!');
//Do whatever you want
}
});
JS (with jQuery) :
var myForm = $('#myForm');
var myInput = $('#myInput');
myForm.on('submit', function(pEvent) {
if(myInput.val() === '') {
pEvent.preventDefault(); //Prevents the form to be sent
alert('Ho! Stop!');
}
});
Demo : http://jsfiddle.net/af9qvkmp/9/
Here is the demo, based on jQuery!
HTML
<form action="" method="POST" id="form">
<input id="input1" type="text" />
<input id="input2" type="text" />
<input id="input3" type="text" />
<input id="input4" type="text" />
<input id="input5" type="text" />
<input type="submit" />
</form>
JS
$(function() {
$('#form').on('submit', function(event) {
var isError = false;
$(this).find('input[type="text"]').each(function() {
if($(this).val() == '') {
console.log($(this));
isError = true;
return false;
}
});
if(isError) {
event.preventDefault();
alert("Got Error");
} else {
// Submit the form
}
});
});
In form tag write
<form action="" method="post" enctype="multipart/form-data" onsubmit="return checkform(this);">
This is your input field
<input type="text" name="reviewValue" value="" id='starRate2' required>
Javascript Code:
<script language="JavaScript" type="text/javascript">
function checkform ( form ){
if (form.reviewValue.value == "") {
alert( "Please choice your Rating." );
form.reviewValue.focus();
return false ;
}
return true ;
}
</script>

How to make a required field be invisible if valid?

I have this kind of html:
<form method="post" action="register">
<input type="text" name="name" required />
<button>Next</button>
</form>
When I click the Next button, I want to hide the Name field, but only if it is valid(not empty) and I don't want to submit the form. How can I do this with plain JavaScript?
If you know a way with jQuery, please write that too. Thanks.
Try this:
$('button').click(function() {
var check = $('#name').val();
if (check == '') {
$('#name').hide();
}
})
If the input has no content, it will be hidden.
document.querySelector('form').addEventListener('submit', function (e) {
e.preventDefault();
var input = e.target.firstElementChild;
if(!input.validity.valueMissing) {
input.style.display = 'none';
}
}, false);
<form method="post" action="register">
<input type="text" name="name" required />
<button>Next</button>
</form>
Assuming that you will change "form button" for the ID of the button, and "form input" for the ID of the input. The jQuery code would be something like this:
$("form button").click(function() {
if ($("form input").val() != "")
$("form input").hide();
});
Try this:
<form method="post" action="register">
<div id="steps1">
<input id="txtname" type="text" placeholder="enter name here" name="name" />
<input id="btnNext" type="button" value="next" />
</div>
<div id="complete" style="display:none;">
<input type="text" name="age" placeholder="enter age here" />
<input type="submit" value="submit" />
</div>
</form>
$(document).ready(function () {
$("#btnNext").click(function () {
if ($("#txtname").val() != "") {
$("#steps1").hide();
$("#complete").show();
}
});
});
In jQuery:
$("button").click(function() {
if ($('input[name=name]').val() != '') {
$('input[name=name]').fadeOut(); // Or hide, or css('display', 'none')
}
});
Make class e.g. "validate", which you can attach to your form after clicking Next.
Then in CSS:
.validate input:valid {
display: none;
}
Try onsubmit event:
var validate = function(form) {
var toSubmit = true;
if (form.name.value) { //has some text
form.name.style.display = "none"; //hide the input field
} else {
toSubmit = false;
}
return toSubmit;
};
<form method="post" action="register" onsubmit='return validate(this);'>
<input type="text" name="name" required />
<button>Next</button>
</form>
EDIT
Try blur event:
var validate = function(box) {
if (!box.value) {
alert('This field is required');
box.focus();
}
};
<form method="post" action="register">
<input type="text" name="name" onblur='validate(this);' />
<button>Next</button>
</form>
Read these to understand the code and why.
document.querySelector
EventTarget.addEventListener
onsubmit
event.preventDefault
Constraint validation HTML5
document.querySelector('form').addEventListener('submit', function (e) {
e.preventDefault();
var input = e.target.firstElementChild;
if(!input.validity.valueMissing) {
input.style.display = 'none';
}
}, false);
<form method="post" action="register">
<input type="text" name="name" required />
<button>Next</button>
</form>

HTML form validation issue

<script type="text/javascript">
function check(n,mail,msg)
{
if(name.toLowerCase()== "")
{
alert("Please Enter your name.");
document.getElementById("Name").select();
document.getElementById("Name").focus();
return false;
}
else if(lname.toLowerCase()== "")
{
alert("Please Enter your email.")
document.getElementById("email").select();
document.getElementById("email").focus();
return false;
}
else if(ph == "")
{
alert("Please Enter your Contact Number.")
document.getElementById("message").focus();
return false;
}
return true;
}
=========================================================
<form method="post" name="contact_form" action="contact-form-handler.php">
<p> Your Name:
<input type="text" name="name"></p>
<p>Email Address:
<input type="text" name="email"></p>
<p>Message:
<textarea name="message"></textarea></p>
=========================================================
<input type="button" value="submit" onclick="return check(document.getElementById('name').value,document.getElementById('email').value,document.getElementById('message').value)" />
=========================================================
i am having issues with the HTML validation as when i clicked the button, there is no validation performed.
Instead .. add the validation on the form as below:
<form method="post" name="contact_form" action="contact-form-handler.php"
onsubmit="return validateForm()">
This works 100% times
try this instead for your button:
<input type="button" value="submit" onclick="function(){ check(document.getElementById('name').value,document.getElementById('email').value,document.getElementById('message').value)}" />
<form method="post" name="contact_form" action="contact-form-handler.php">
<p> Your Name:
<input type="text" id="name" name="name"></p>
<p>Email Address:
<input type="text" id="email" name="email"></p>
<p>Message:
<textarea id="message" name="message"></textarea></p>
Use this html markups. It has ids which you have missed.
You are using document.getElementById("name"). But the input field doesn't have id "name". Same for other fields.

JavaScript return false form validation not working

Can you help me, when the validation fails my script should unhide an error message in a p tag and return false but instead my form submits. Can you see where my problem is?
function validate() {
if (document.emailForm.EMAIL_ADDRESS_.value.length==0) {
$('#errorNoAddress').fadeIn();
return false;
}
if (document.emailForm.EMAIL_ADDRESS_.value.length>0) {
var reg = /^([A-Za-z0-9_\-\.])+\#([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
var address = document.emailForm.email.value;
if(reg.test(address) == false) {
$('#errorInvalidAddress').fadeIn();
return false;
}
}
document.emailForm.submit();
return true;
}
<form id="emailForm" name="emailForm" action="http://domain.com/formhandler.php" method="post">
<p id="errorNoAddress" class="error">Please enter an e-mail address.</p>
<p id="errorInvalidAddress" class="error">Please enter a valid email address.</p>
<label for="EMAIL_ADDRESS_">E-mail</label>
<input type="hidden" id="QUICK_SIGN_UP" name="QUICK_SIGN_UP" value="" />
<input type="image" src="btn-submit.gif" value="Submit" onclick="validate();" />
</form>
try <input type="image" src="btn-submit.gif" value="Submit" onclick="return validate();" />

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