How to retain the values of a label after invoking a function - javascript

I am just wondering why the label's text which i am setting below doesn't persists. If the user enters valid username & password say(xxx & yyy) then the label should set with Welcome xxx, else set with "Login Failed". Here i see the label is set with right text, but in a fraction of second the page refreshes and all fields are set empty and the label text is erased. How to overcome this? I am trying in Firefox.
Following is my html code:
<html>
<body>
<form>
User Name: <input type="text" id="uname"/><br/><br/>
Password : <input type="text" id="pwd"/><br/><br/>
<input type="submit" value="Login"onclick="validateLogin()"/><br/>
<label id="label1" /><br/>
<label id="label2" /><br/>
</form>
<script>
function validateLogin()
{
var v1=document.getElementById("uname").value;
var v2=document.getElementById("pwd").value;
if(v1=="xxx" && v2=="yyy")
{
document.getElementById("label1").innerHTML="Welcome :"+v1;
}
else
{
alert("Invalid login");
document.getElementById("label2").innerHTML="Login Failed!!!";
}
}
</script>
</body>
</html>

Change markup like this
<input type="submit" value="Login"onclick="return validateLogin()"/> <!-- added return -->
Javascript
if (v1 == "xxx" && v2 == "yyy") {
document.getElementById("label1").innerHTML = "Welcome :" + v1;
return false; /* return */
} else {
alert("Invalid login");
document.getElementById("label2").innerHTML = "Login Failed!!!";
return false; /* return */
}
Demo
Note: This will work as expected but those values need to post on server side while condition is true so in if block write your code to post data on server rather than printing it to the label and don't forget to remove return false from if after writing the code

Related

Javascript function gets called and then page resets back to initial state [duplicate]

How would I go about preventing the page from refreshing when pressing the send button without any data in the fields?
The validation is setup working fine, all fields go red but then the page is immediately refreshed. My knowledge of JS is relatively basic.
In particular I think the processForm() function at the bottom is 'bad'.
HTML
<form id="prospects_form" method="post">
<input id="form_name" tabindex="1" class="boxsize" type="text" name="name" placeholder="Full name*" maxlength="80" value="" />
<input id="form_email" tabindex="2" class="boxsize" type="text" name="email" placeholder="Email*" maxlength="100" value="" />
<input id="form_subject" class="boxsize" type="text" name="subject" placeholder="Subject*" maxlength="50" value="FORM: Row for OUBC" />
<textarea id="form_message" class="boxsize" name="message" placeholder="Message*" tabindex="3" rows="6" cols="5" maxlength="500"></textarea>
<button id="form_send" tabindex="5" class="btn" type="submit" onclick="return processForm()">Send</button>
<div id="form_validation">
<span class="form_captcha_code"></span>
<input id="form_captcha" class="boxsize" type="text" name="form_captcha" placeholder="Enter code" tabindex="4" value="" />
</div>
<div class="clearfix"></div>
</form>
JS
$(document).ready(function() {
// Add active class to inputs
$("#prospects_form .boxsize").focus(function() { $(this).addClass("hasText"); });
$("#form_validation .boxsize").focus(function() { $(this).parent().addClass("hasText"); });
// Remove active class from inputs (if empty)
$("#prospects_form .boxsize").blur(function() { if ( this.value === "") { $(this).removeClass("hasText"); } });
$("#form_validation .boxsize").blur(function() { if ( this.value === "") { $(this).parent().removeClass("hasText"); } });
///////////////////
// START VALIDATION
$("#prospects_form").ready(function() {
// DEFINE GLOBAL VARIABLES
var valName = $('#form_name'),
valEmail = $("#form_email"),
valEmailFormat = /^(([^<>()[\]\\.,;:\s#\"]+(\.[^<>()[\]\\.,;:\s#\"]+)*)|(\".+\"))#((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/,
valMsg = $('#form_message'),
valCaptcha = $('#form_captcha'),
valCaptchaCode = $('.form_captcha_code');
// Generate captcha
function randomgen() {
var rannumber = "";
// Iterate through 1 to 9, 4 times
for(ranNum=1; ranNum<=4; ranNum++){ rannumber+=Math.floor(Math.random()*10).toString(); }
// Apply captcha to element
valCaptchaCode.html(rannumber);
}
randomgen();
// CAPTCHA VALIDATION
valCaptcha.blur(function() {
function formCaptcha() {
if ( valCaptcha.val() == valCaptchaCode.html() ) {
// Incorrect
valCaptcha.parent().addClass("invalid");
return false;
} else {
// Correct
valCaptcha.parent().removeClass("invalid");
return true;
}
}
formCaptcha();
});
// Remove invalid class from captcha if typing
valCaptcha.keypress(function() {
valCaptcha.parent().removeClass("invalid");
});
// EMAIL VALIDATION (BLUR)
valEmail.blur(function() {
function formEmail() {
if (!valEmailFormat.test(valEmail.val()) && valEmail.val() !== "" ) {
// Incorrect
valEmail.addClass("invalid");
} else {
// Correct
valEmail.removeClass("invalid");
}
}
formEmail();
});
// Remove invalid class from email if typing
valEmail.keypress(function() {
valEmail.removeClass("invalid");
});
// VALIDATION ON SUBMIT
$('#prospects_form').submit(function() {
console.log('user hit send button');
// EMAIL VALIDATION (SUBMIT)
function formEmailSubmit() {
if (!valEmailFormat.test(valEmail.val())) {
// Incorrect
valEmail.addClass("invalid");
} else {
// Correct
valEmail.removeClass("invalid");
}
}
formEmailSubmit();
// Validate captcha
function formCaptchaSubmit() {
if( valCaptcha.val() === valCaptchaCode.html() ) {
// Captcha is correct
} else {
// Captcha is incorrect
valCaptcha.parent().addClass("invalid");
randomgen();
}
}
formCaptchaSubmit();
// If NAME field is empty
function formNameSubmit() {
if ( valName.val() === "" ) {
// Name is empty
valName.addClass("invalid");
} else {
valName.removeClass("invalid");
}
}
formNameSubmit();
// If MESSAGE field is empty
function formMessageSubmit() {
if ( valMsg.val() === "" ) {
// Name is empty
valMsg.addClass("invalid");
} else {
valMsg.removeClass("invalid");
}
}
formMessageSubmit();
// Submit form (if all good)
function processForm() {
if ( formEmailSubmit() && formCaptchaSubmit() && formNameSubmit() && formMessageSubmit() ) {
$("#prospects_form").attr("action", "/clients/oubc/row-for-oubc-send.php");
$("#form_send").attr("type", "submit");
return true;
} else if( !formEmailSubmit() ) {
valEmail.addClass("invalid");
return false;
} else if ( !formCaptchaSubmit() ) {
valCaptcha.parent().addClass("invalid");
return false;
} else if ( !formNameSubmit() ) {
valName.addClass("invalid");
return false;
} else if ( !formMessageSubmit() ) {
valMsg.addClass("invalid");
return false;
} else {
return false;
}
}
});
});
// END VALIDATION
/////////////////
});
You can prevent the form from submitting with
$("#prospects_form").submit(function(e) {
e.preventDefault();
});
Of course, in the function, you can check for empty fields, and if anything doesn't look right, e.preventDefault() will stop the submit.
Without jQuery:
var form = document.getElementById("myForm");
function handleForm(event) { event.preventDefault(); }
form.addEventListener('submit', handleForm);
Add this onsubmit="return false" code:
<form onsubmit="return false">
That fixed it for me. It will still run the onClick function you specify.
Replace button type to button:
<button type="button">My Cool Button</button>
One great way to prevent reloading the page when submitting using a form is by adding return false with your onsubmit attribute.
<form onsubmit="yourJsFunction();return false">
<input type="text"/>
<input type="submit"/>
</form>
You can use this code for form submission without a page refresh. I have done this in my project.
$(function () {
$('#myFormName').on('submit',function (e) {
$.ajax({
type: 'post',
url: 'myPageName.php',
data: $('#myFormName').serialize(),
success: function () {
alert("Email has been sent!");
}
});
e.preventDefault();
});
});
This problem becomes more complex when you give the user 2 possibilities to submit the form:
by clicking on an ad hoc button
by hitting Enter key
In such a case you will need a function which detects the pressed key in which you will submit the form if Enter key was hit.
And now comes the problem with IE (in any case version 11)
Remark:
This issue does not exist with Chrome nor with FireFox !
When you click the submit button the form is submitted once; fine.
When you hit Enter the form is submitted twice ... and your servlet will be executed twice. If you don't have PRG (post redirect get) architecture serverside the result might be unexpected.
Even though the solution looks trivial, it tooks me many hours to solve this problem, so I hope it might be usefull for other folks.
This solution has been successfully tested, among others, on IE (v 11.0.9600.18426), FF (v 40.03) & Chrome (v 53.02785.143 m 64 bit)
The source code HTML & js are in the snippet. The principle is described there.
Warning:
You can't test it in the snippet because the post action is not
defined and hitting Enter key might interfer with stackoverflow.
If you faced this issue, then just copy/paste js code to your environment and adapt it to your context.
/*
* inForm points to the form
*/
var inForm = document.getElementById('idGetUserFrm');
/*
* IE submits the form twice
* To avoid this the boolean isSumbitted is:
* 1) initialized to false when the form is displayed 4 the first time
* Remark: it is not the same event as "body load"
*/
var isSumbitted = false;
function checkEnter(e) {
if (e && e.keyCode == 13) {
inForm.submit();
/*
* 2) set to true after the form submission was invoked
*/
isSumbitted = true;
}
}
function onSubmit () {
if (isSumbitted) {
/*
* 3) reset to false after the form submission executed
*/
isSumbitted = false;
return false;
}
}
<!DOCTYPE html>
<html>
<body>
<form id="idGetUserFrm" method="post" action="servletOrSomePhp" onsubmit="return onSubmit()">
First name:<br>
<input type="text" name="firstname" value="Mickey">
<input type="submit" value="Submit">
</form>
</body>
</html>
The best solution is onsubmit call any function whatever you want and return false after it.
onsubmit="xxx_xxx(); return false;"
Most people would prevent the form from submitting by calling the event.preventDefault() function.
Another means is to remove the onclick attribute of the button, and get the code in processForm() out into .submit(function() { as return false; causes the form to not submit. Also, make the formBlaSubmit() functions return Boolean based on validity, for use in processForm();
katsh's answer is the same, just easier to digest.
(By the way, I'm new to stackoverflow, give me guidance please. )
In pure Javascript, use: e.preventDefault()
e.preventDefault() is used in jquery but works in javascript.
document.querySelector(".buttonclick").addEventListener("click",
function(e){
//some code
e.preventDefault();
})
The best way to do so with JS is using preventDefault() function.
Consider the code below for reference:
function loadForm(){
var loginForm = document.querySelector('form'); //Selecting the form
loginForm.addEventListener('submit', login); //looking for submit
}
function login(e){
e.preventDefault(); //to stop form action i.e. submit
}
Personally I like to validate the form on submit and if there are errors, just return false.
$('form').submit(function() {
var error;
if ( !$('input').val() ) {
error = true
}
if (error) {
alert('there are errors')
return false
}
});
http://jsfiddle.net/dfyXY/
$("#buttonID").click(function (e) {
e.preventDefault();
//some logic here
}
If you want to use Pure Javascript then the following snippet will be better than anything else.
Suppose:
HTML:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Form Without Submiting With Pure JS</title>
<script type="text/javascript">
window.onload = function(){
/**
* Just Make sure to return false so that your request will not go the server script
*/
document.getElementById('simple_form').onsubmit = function(){
// After doing your logic that you want to do
return false
}
}
</script>
</head>
<body>
</body>
</html>
<form id="simple_form" method="post">
<!-- Your Inputs will go here -->
<input type="submit" value="Submit Me!!" />
</form>
Hope so it works for You!!
Just use "javascript:" in your action attribute of form if you are not using action.
In my opinion, most answers are trying to solve the problem asked on your question, but I don't think that's the best approach for your scenario.
How would I go about preventing the page from refreshing when pressing the send button without any data in the fields?
A .preventDefault() does indeed not refresh the page. But I think that a simple require on the fields you want populated with data, would solve your problem.
<form id="prospects_form" method="post">
<input id="form_name" tabindex="1" class="boxsize" type="text" name="name" placeholder="Full name*" maxlength="80" value="" required/>
<input id="form_email" tabindex="2" class="boxsize" type="text" name="email" placeholder="Email*" maxlength="100" value="" required/>
<input id="form_subject" class="boxsize" type="text" name="subject" placeholder="Subject*" maxlength="50" value="FORM: Row for OUBC" required/>
<textarea id="form_message" class="boxsize" name="message" placeholder="Message*" tabindex="3" rows="6" cols="5" maxlength="500"></textarea>
</form>
Notice the require tag added at the end of each input. The result will be the same: not refreshing the page without any data in the fields.
<form onsubmit="myFunction(event)">
Name : <input type="text"/>
<input class="submit" type="submit">
</form>
<script>
function myFunction(event){
event.preventDefault();
//code here
}
</script>
function ajax_form(selector, obj)
{
var form = document.querySelectorAll(selector);
if(obj)
{
var before = obj.before ? obj.before : function(){return true;};
var $success = obj.success ? obj.success: function(){return true;};
for (var i = 0; i < form.length; i++)
{
var url = form[i].hasAttribute('action') ? form[i].getAttribute('action') : window.location;
var $form = form[i];
form[i].submit = function()
{
var xhttp = new XMLHttpRequest();
xhttp.open("POST", url, true);
var FD = new FormData($form);
/** prevent submiting twice */
if($form.disable === true)
return this;
$form.disable = true;
if(before() === false)
return;
xhttp.addEventListener('load', function()
{
$form.disable = false;
return $success(JSON.parse(this.response));
});
xhttp.send(FD);
}
}
}
return form;
}
Didn't check how it works. You can also bind(this) so it will work like jquery ajaxForm
use it like:
ajax_form('form',
{
before: function()
{
alert('submiting form');
// if return false form shouldn't be submitted
},
success:function(data)
{
console.log(data)
}
}
)[0].submit();
it return nodes so you can do something like submit i above example
so far from perfection but it suppose to work, you should add error handling or remove disable condition
Sometimes e.preventDefault(); works then developers are happy but sometimes not work then developers are sad then I found solution why sometimes not works
first code sometimes works
$("#prospects_form").submit(function(e) {
e.preventDefault();
});
second option why not work?
This doesn't work because jquery or other javascript library not loading properly you can check it in console that all jquery and javascript files are loaded properly or not.
This solves my problem. I hope this will be helpful for you.
I hope this will be the last answer
$('#the_form').submit(function(e){
e.preventDefault()
alert($(this).serialize())
// var values = $(this).serialize()
// logic....
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form id="the_form">
Label-A <input type="text" name='a'required><br>
Label-B <input type="text" name="b" required><br>
Label-C <input type="password" name="c" required><br>
Label-D <input type="number" name="d" required><br>
<input type="submit" value="Save without refresh">
</form>
You can do this by clearing the state as below. add this to very beginning of the document.ready function.
if ( window.history.replaceState ) {
window.history.replaceState( null, null, window.location.href );
}

Snippet of code not working

Below is a simplified snippet of code from a form validation script. It does not work...
When the form is submitted and the user has left "inputfield" empty, the first alert pops up. After the user has entered something in "inputfield", the second alert pops up when the user clicks submit.
Afterwards, the script should return false and continue validation. I need both alerts to be included in the same else if. What am I doing wrong? The alerts do not show and the form validation ignores this portion of code...
} else if (myform.inputfield.value=="") {
alert ('Please enter something in the text field!');
}
if (myform.inputfield.value!=="") {
alert ('Thank you for entering something in the field!');
return false;
}
Isn't it better to declare a flag and return the it as a result? take the following sample into account:
var validationResult = true;
...
} else if (myform.inputfield.value=="") {
validationResult = false;
alert ('Please enter something in the text field!');
}
if (myform.inputfield.value!=="") {
alert ('Thank you for entering something in the field!');
validationResult = false;
}
return validationResult;
I agree rather use document.getElementById, or jQuery $('#input1').val()
<script type="text/javascript">
function validate() {
if (document.getElementById('input1').value == "") {
alert('Please enter something in the text field!');
}
if (document.getElementById('input2') !== "") {
alert('Thank you for entering something in the field!');
return false;
}
}
</script>
</head>
<body>
<form onsubmit="return validate()">
<input id="input1" />
<input id="input2" />
<input type="submit" value="OK" />
</form>
</body>
You might have a return statement before the specified line of code?

User Validation in Java Script using Static Password

I am new to Java Script and recently got a program in JS For Implementing Static Password Protection
Here is my code :
<html>
<head>
<title>
User Validation : 2nd Program
</title>
<script "javascript">
function validate()
{
alert(form.username.value)
alert(document.getelementbyId(username).value);
alert(form.password.value)
if(form.username.value == "sample" && form.password.value =="password")
{
alert("User Validated ");
continue();
}
else
{
alert("Incorrect Username or Password" );
}
}
</script>
</head>
<body>
<text align=center>
<form name="form" onsubmit="validate()">
Username <input type="text" name="username" />
<br />
<br />
Password <input type="password" name="password" maxlength=10 />
<input type="submit" />
</form>
</text>
</body>
Now , I have defined a username->"sample" by default and password ->"password" by default for user validation .
But whenever after submitting the form resets again without executing the validate function !
As am new to JS ignore me for a silly mistake .
Also suggest some best books for Learning JS and JSP from the scratch !
change onsubmit="validate()" to onsubmit="return validate();".
this way, when validate returns false, the form won't submit. you'd also have to change the validate func to return false when the form doesn't validate, the resulting code would be:
function validate()
{
alert(form.username.value)
alert(document.getelementbyId(username).value);
alert(form.password.value)
if(form.username.value == "sample" && form.password.value =="password")
{
alert("User Validated ");
return true;
}
else
{
alert("Incorrect Username or Password" );
return false;
}
}
Update: continue and break illustrated.
while(true) {
// :loopStart
var randomNumber = Math.random();
if (randomNumber < .5) {
continue; //skips the rest of the code and goes back to :loopStart
}
if (randomNumber >= .6) {
break; //exits the while loop (resumes execution at :loopEnd)
}
alert('value is between .5 and .6');
}
// :loopEnd
just in case, :loopStart and :loopEnd aren't special identifiers or anything, they're just comments to help you trace the code better

Onclick event; If and Else

All right so I am doing a javascript code for a login type form and it will lead you to a new page. Here it is:
function submit1()
{
var x=document.getElementById("username");
var y=document.getElementById("password");
if (x.value=="username" && y.value=="password")
{
window.location="Example.php";
}
else
{
window.alert=("The information you have submitted is incorrect and needs to be submitted again!");
}
}
When ever I am hitting the submit button it takes me straight to the page instead of checking to see if it right. Please help!
Thank you in advanced! To let you know this is not a permanet login page!
The easy way to do this would be to use a button input:
<input type="button" value="Check" onclick = "submit1();" />
The alternative is to prevent this default behavior of a submit type input, by making the handler return false. Your HTML would look like this:
<input type="submit" value="Check" onclick = "return submit1();" />
Your function would need to be changed a well (considering the fact that you want it to not redirect). I am assuming you want to preserve data entered, so I am not going to use window.location to redirect. Instead, I am going to allow the form to be submitted:
function submit1()
{
var x=document.getElementById("username");
var y=document.getElementById("password");
if (x.value == "username" && y.value == "password") {
window.alert=("The information you have submitted is incorrect and needs to be submitted again!");
return false;
}
}
<html>
<head>
<title>
Login page
</title>
</head>
<body>
<h1 style="font-family:Comic Sans Ms;text-align="center";font-size:20pt;
color:#00FF00;>
Simple Login Page
</h1>
<form name="login">
Username<input type="text" name="userid"/>
Password<input type="password" name="pswrd"/>
<input type="button" onclick="check(this.form)" value="Login"/>
<input type="reset" value="Cancel"/>
</form>
<script language="javascript">
function check(form)/*function to check userid & password*/
{
/*the following code checkes whether the entered userid and password are matching*/
if(form.userid.value == "myuserid" && form.pswrd.value == "mypswrd")
{
window.location="Example.php"; /*opens the target page while Id & password matches*/
}
else
{
alert("Error Password or Username")/*displays error message*/
}
}
</script>
</body>
</html>
The event needs to cancel the default event and return false. This will prevent the form from submitting.
HOWEVER, it should be a non-issue if the form submits anyway, because JavaScript CANNOT be trusted and therefore you MUST validate all input server-side.
<form method="post" action="." id="myform">
<!-- form contents --->
</form>
<script type="text/javascript">
(function () {
var f = document.getElementById('myform'), // get your form element
x = document.getElementById('username'),
y = document.getElementById('password'),
handler;
handler = function (e) {
e.preventDefault(); // stop submit
if (x.value=='username' && y.value=='password') {
window.location = 'Example.php';
} else {
window.alert('The information...');
}
};
// listen to submit event
if ('addEventListener' in f) {
f.addEventListener('submit', handler, false);
} else { // handle also IE...
f.attachEvent('submit', function () {
handler(window.event);
});
}
}());
</script>
anyway it looks like you're trying to check login/password from JS what is not greatest idea (anyone can just look into source and read it)

Set custom HTML5 required field validation message

Required field custom validation
I have one form with many input fields. I have put html5 validations
<input type="text" name="topicName" id="topicName" required />
when I submit the form without filling this textbox it shows default message like
"Please fill out this field"
Can anyone please help me to edit this message?
I have a javascript code to edit it, but it's not working
$(document).ready(function() {
var elements = document.getElementsByName("topicName");
for (var i = 0; i < elements.length; i++) {
elements[i].oninvalid = function(e) {
e.target.setCustomValidity("");
if (!e.target.validity.valid) {
e.target.setCustomValidity("Please enter Room Topic Title");
}
};
elements[i].oninput = function(e) {
e.target.setCustomValidity("");
};
}
})
Email custom validations
I have following HTML form
<form id="myform">
<input id="email" name="email" type="email" />
<input type="submit" />
</form>
Validation messages I want like.
Required field: Please Enter Email Address
Wrong Email: 'testing#.com' is not a Valid Email Address. (here, entered email address displayed in textbox)
I have tried this.
function check(input) {
if(input.validity.typeMismatch){
input.setCustomValidity("'" + input.value + "' is not a Valid Email Address.");
}
else {
input.setCustomValidity("");
}
}
This function is not working properly, Do you have any other way to do this? It would be appreciated.
Code snippet
Since this answer got very much attention, here is a nice configurable snippet I came up with:
/**
* #author ComFreek <https://stackoverflow.com/users/603003/comfreek>
* #link https://stackoverflow.com/a/16069817/603003
* #license MIT 2013-2015 ComFreek
* #license[dual licensed] CC BY-SA 3.0 2013-2015 ComFreek
* You MUST retain this license header!
*/
(function (exports) {
function valOrFunction(val, ctx, args) {
if (typeof val == "function") {
return val.apply(ctx, args);
} else {
return val;
}
}
function InvalidInputHelper(input, options) {
input.setCustomValidity(valOrFunction(options.defaultText, window, [input]));
function changeOrInput() {
if (input.value == "") {
input.setCustomValidity(valOrFunction(options.emptyText, window, [input]));
} else {
input.setCustomValidity("");
}
}
function invalid() {
if (input.value == "") {
input.setCustomValidity(valOrFunction(options.emptyText, window, [input]));
} else {
input.setCustomValidity(valOrFunction(options.invalidText, window, [input]));
}
}
input.addEventListener("change", changeOrInput);
input.addEventListener("input", changeOrInput);
input.addEventListener("invalid", invalid);
}
exports.InvalidInputHelper = InvalidInputHelper;
})(window);
Usage
→ jsFiddle
<input id="email" type="email" required="required" />
InvalidInputHelper(document.getElementById("email"), {
defaultText: "Please enter an email address!",
emptyText: "Please enter an email address!",
invalidText: function (input) {
return 'The email address "' + input.value + '" is invalid!';
}
});
More details
defaultText is displayed initially
emptyText is displayed when the input is empty (was cleared)
invalidText is displayed when the input is marked as invalid by the browser (for example when it's not a valid email address)
You can either assign a string or a function to each of the three properties.
If you assign a function, it can accept a reference to the input element (DOM node) and it must return a string which is then displayed as the error message.
Compatibility
Tested in:
Chrome Canary 47.0.2
IE 11
Microsoft Edge (using the up-to-date version as of 28/08/2015)
Firefox 40.0.3
Opera 31.0
Old answer
You can see the old revision here: https://stackoverflow.com/revisions/16069817/6
You can simply achieve this using oninvalid attribute,
checkout this demo code
<form>
<input type="email" pattern="[^#]*#[^#]" required oninvalid="this.setCustomValidity('Put here custom message')"/>
<input type="submit"/>
</form>
Codepen Demo: https://codepen.io/akshaykhale1992/pen/yLNvOqP
HTML:
<form id="myform">
<input id="email" oninvalid="InvalidMsg(this);" name="email" oninput="InvalidMsg(this);" type="email" required="required" />
<input type="submit" />
</form>
JAVASCRIPT :
function InvalidMsg(textbox) {
if (textbox.value == '') {
textbox.setCustomValidity('Required email address');
}
else if (textbox.validity.typeMismatch){{
textbox.setCustomValidity('please enter a valid email address');
}
else {
textbox.setCustomValidity('');
}
return true;
}
Demo :
http://jsfiddle.net/patelriki13/Sqq8e/
Try this:
$(function() {
var elements = document.getElementsByName("topicName");
for (var i = 0; i < elements.length; i++) {
elements[i].oninvalid = function(e) {
e.target.setCustomValidity("Please enter Room Topic Title");
};
}
})
I tested this in Chrome and FF and it worked in both browsers.
Man, I never have done that in HTML 5 but I'll try. Take a look on this fiddle.
I have used some jQuery, HTML5 native events and properties and a custom attribute on input tag(this may cause problem if you try to validade your code). I didn't tested in all browsers but I think it may work.
This is the field validation JavaScript code with jQuery:
$(document).ready(function()
{
$('input[required], input[required="required"]').each(function(i, e)
{
e.oninput = function(el)
{
el.target.setCustomValidity("");
if (el.target.type == "email")
{
if (el.target.validity.patternMismatch)
{
el.target.setCustomValidity("E-mail format invalid.");
if (el.target.validity.typeMismatch)
{
el.target.setCustomValidity("An e-mail address must be given.");
}
}
}
};
e.oninvalid = function(el)
{
el.target.setCustomValidity(!el.target.validity.valid ? e.attributes.requiredmessage.value : "");
};
});
});
Nice. Here is the simple form html:
<form method="post" action="" id="validation">
<input type="text" id="name" name="name" required="required" requiredmessage="Name is required." />
<input type="email" id="email" name="email" required="required" requiredmessage="A valid E-mail address is required." pattern="^[a-zA-Z0-9_.-]+#[a-zA-Z0-9-]+.[a-zA-Z0-9]+$" />
<input type="submit" value="Send it!" />
</form>
The attribute requiredmessage is the custom attribute I talked about. You can set your message for each required field there cause jQuery will get from it when it will display the error message. You don't have to set each field right on JavaScript, jQuery does it for you. That regex seems to be fine(at least it block your testing#.com! haha)
As you can see on fiddle, I make an extra validation of submit form event(this goes on document.ready too):
$("#validation").on("submit", function(e)
{
for (var i = 0; i < e.target.length; i++)
{
if (!e.target[i].validity.valid)
{
window.alert(e.target.attributes.requiredmessage.value);
e.target.focus();
return false;
}
}
});
I hope this works or helps you in anyway.
This works well for me:
jQuery(document).ready(function($) {
var intputElements = document.getElementsByTagName("INPUT");
for (var i = 0; i < intputElements.length; i++) {
intputElements[i].oninvalid = function (e) {
e.target.setCustomValidity("");
if (!e.target.validity.valid) {
if (e.target.name == "email") {
e.target.setCustomValidity("Please enter a valid email address.");
} else {
e.target.setCustomValidity("Please enter a password.");
}
}
}
}
});
and the form I'm using it with (truncated):
<form id="welcome-popup-form" action="authentication" method="POST">
<input type="hidden" name="signup" value="1">
<input type="email" name="email" id="welcome-email" placeholder="Email" required></div>
<input type="password" name="passwd" id="welcome-passwd" placeholder="Password" required>
<input type="submit" id="submitSignup" name="signup" value="SUBMIT" />
</form>
You can do this setting up an event listener for the 'invalid' across all the inputs of the same type, or just one, depending on what you need, and then setting up the proper message.
[].forEach.call( document.querySelectorAll('[type="email"]'), function(emailElement) {
emailElement.addEventListener('invalid', function() {
var message = this.value + 'is not a valid email address';
emailElement.setCustomValidity(message)
}, false);
emailElement.addEventListener('input', function() {
try{emailElement.setCustomValidity('')}catch(e){}
}, false);
});
The second piece of the script, the validity message will be reset, since otherwise won't be possible to submit the form: for example this prevent the message to be triggered even when the email address has been corrected.
Also you don't have to set up the input field as required, since the 'invalid' will be triggered once you start typing in the input.
Here is a fiddle for that: http://jsfiddle.net/napy84/U4pB7/2/
Hope that helps!
Just need to get the element and use the method setCustomValidity.
Example
var foo = document.getElementById('foo');
foo.setCustomValidity(' An error occurred');
Use the attribute "title" in every input tag and write a message on it
you can just simply using the oninvalid=" attribute, with the bingding the this.setCustomValidity() eventListener!
Here is my demo codes!(you can run it to check out!)
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>oninvalid</title>
</head>
<body>
<form action="https://www.google.com.hk/webhp?#safe=strict&q=" method="post" >
<input type="email" placeholder="xgqfrms#email.xyz" required="" autocomplete="" autofocus="" oninvalid="this.setCustomValidity(`This is a customlised invalid warning info!`)">
<input type="submit" value="Submit">
</form>
</body>
</html>
reference link
http://caniuse.com/#feat=form-validation
https://www.w3.org/TR/html51/sec-forms.html#sec-constraint-validation
You can add this script for showing your own message.
<script>
input = document.getElementById("topicName");
input.addEventListener('invalid', function (e) {
if(input.validity.valueMissing)
{
e.target.setCustomValidity("Please enter topic name");
}
//To Remove the sticky error message at end write
input.addEventListener('input', function (e) {
e.target.setCustomValidity('');
});
});
</script>
For other validation like pattern mismatch you can add addtional if else condition
like
else if (input.validity.patternMismatch)
{
e.target.setCustomValidity("Your Message");
}
there are other validity conditions like rangeOverflow,rangeUnderflow,stepMismatch,typeMismatch,valid
use it on the onvalid attribute as follows
oninvalid="this.setCustomValidity('Special Characters are not allowed')

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