Develop Reference

Allow edu domain emails in form jquery

I tried various solutions but it didn't work. Not that good with JavaScript especially with RegEx.
Found this solution online, but couldn't modify it.
Basically I need to allow EDU domain in email field. I think it would be #ohio.edu or #ohio.edu.com or something like that. How can I say that if there isn't phrase "edu" after #, then don't allow the registration?
$(".single-memberpressproduct.postid-1945 .mepr-submit").click(function() {
validateEmail(jQuery("input#user_email1").val());
return false;
});
function validateEmail(email) {
var emailRegx = /b(?:(?![_.-])(?!.*[_.-]{2})[a-z0-9_.-]+(?<![_.-]))#(?:(?!-)(?!.*--)[a-z0-9-]+(?<!-).)*.edub/i;
if (emailRegx.test(email)) {
if (email.indexOf('#edu.com', email.length - '#edu.com'.length) !== -1) {
alert('Submission was successful.');
} else {
alert('Not a valid e-mail address #.');
}
} else {
alert('Not a valid e-mail address.');
}
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<form class="single-memberpressproduct postid-1945">
<input type="text" id="user_email1" value="" />
<input type="submit" class="mepr-submit" />
</form>

I ended up using different approach.
<script>
jQuery('.single-memberpressproduct.postid-1945 .mepr-submit').attr("disabled", "disabled");
var youtubeRegex = /edu/i;
jQuery('input#user_email1').keyup(function(){
jQuery(".single-memberpressproduct.postid-1945 .mepr-submit").attr("disabled", !youtubeRegex.test(this.value));
});
</script>

JS Student Email Validation

I am a beginner in Javascript and am looking to find a solution to why the code below is not working.
I've reviewed several tutorials here on StackOverflow and believe it should work... but it's not.
The HTML looks like this:
<form id="personalInfo">
<h2>Email: </h2>
<input type="text" name="Email" id="Email">
<br>
</form>
<input type="button" onclick = "validateEmail()">
The Javascript looks like this:
function validateEmail()
{
var reg = /^([A-Za-z0-9_\-\.]){1,}\#([A-Za-z0-9_\-\.]){1,}\.([A-Za-z]{2,4})$/;
var address = document.forms[personalInfo].elements[Email].value;
if (reg.test(address) == false) {
alert ("Email not valid");
return false;
}
return true;
}
By my accounts, this should pop up an alert if the email address entered by the user is not valid.
Instead, nothing happens at all. I'm not sure if the test is even run.

function validateEmail() {
// There are, I feel, better version of this regex online
// You can check "https://emailregex.com/"
var reg = /^([A-Za-z0-9_\-\.]){1,}\#([A-Za-z0-9_\-\.]){1,}\.([A-Za-z]{2,4})$/;
// document.getElementById() - Easier to read & understand, and more widely used
var address = document.getElementById('Email').value;
// Corrected your returns - not the main issue in the function, but the old
// returns might have caused confusion
if (reg.test(address) == false) {
alert("Email not valid");
return false
}
return true
}
<form id="personalInfo">
<h2>Email: </h2>
<input type="text" name="Email" id="Email">
</form>
<!-- You had a typo on the onclick but has since been fixed -->
<input type="button" onclick="validateEmail()" value="Submit">

Two issues here:
1- In your HTML, you are missing an = sign here: onclick"validateEmail()" (Edit: seems you fixed it now)
2- in your Javascript, the indices personalInfo and Email are strings, wrap them in quotation marks:
var address = document.forms['personalInfo'].elements['Email'].value;
function validateEmail()
{
var reg = /^([A-Za-z0-9_\-\.]){1,}\#([A-Za-z0-9_\-\.]){1,}\.([A-Za-z]{2,4})$/;
var address = document.forms['personalInfo'].elements['Email'].value;
if (reg.test(address)== false)
{
alert ("Email not valid");
return false
}
return true;
}
<form id="personalInfo">
<h2>Email: </h2> <input type="text" name="Email" id="Email"> <br>
</form>
<input type="button" onclick="validateEmail()">

When dealing with email inputs, set the input type to email instead of text - like so:
<input name="my-email" type="email" />"
Then the browser will perform validation on the input; such as if the input doesn't have the # present.

Javascript validation nightmare

I'm trying to get my "username" and "password" fields to verify that there is information in them before submitting the form.
What should I need to add to my HTML and to my JavaScript to have them work! If you want to suggest a new JavaScript, please do!
HTML:
<form action="validateForm.html" id="registrationForm">
<label for="username" id="usernameLabel">* Username:</label>
<input type="text" name="username" id="username" value="Your username" />
<div id="usernameError" style="display:none"></div>
<br/><br/>
<label for="password" id="passwordLabel">* Password:</label>
<input type="password" name="password" id="password" />
<div id="passwordError" style="display:none"></div>
<br/><br/>
<input type="submit" value="Submit Form" id="submit" />
</form>
JavaScript
function validateForm()
{
if(!document.getElementByName("username"))
{
alert("Username field is required!");
}
if(!document.forms[0].username){
alert("Username field is required!");
}
if(!document.for (var i = username.length - 1; i >= 0; i--) {
alert("Username field is required!")
};)
}

One way would be getting your input by id and then validate its value
HTML
<input type="text" id="username" />
<input type="password" id="password" />
JS
function validateForm()
{
if(!document.getElementById("username").value) // true if input value is null, undefined or ""
{
alert("Username field is required!");
}
else if(!document.getElementById("password").value)
{
alert("Username field is required!");
}
}
(i strongly recommend you to use more attractive ways of giving users feedback than JS alerts)

I think all of those checks are incorrect in some for, let's start with the first one:
if(!document.getElementByName("username"))
{
alert("Username field is required!");
}
It's document.getElementsByName() (notice the plural)
The function returns an array of elements, so you'd still need to check for the value of the one you want (probably 0)
This is going to be true always as the field exist, you need to check the value in the input, but right now you are just checking the existence of the input.
Next one is similar:
if(!document.forms[0].username){
alert("Username field is required!");
}
You are checking the existence of the field, not its value
This type of selection is not recommended, you should be using a document.getElementBy... better.
And finally:
if(!document.for (var i = username.length - 1; i >= 0; i--) {
alert("Username field is required!")
};)
It looks like you tried to make a for loop but copy-pasted from above and got this mess... not even going to try to understand why the loop.
Recommendations:
Use the attribute id and read the fields using document.getElementById()
To check if a field has content, check its value: .value
Add an event handler for the form (onsubmit="validateForm()")
Make the form validator return false if one of the fields is incorrect (otherwise the form will be sent even with the incorrect fields)
Optionally: use the HTML5 required attribute.
So the function would look like:
function validateForm()
{
if(document.getElementById("username").value == "")
{
alert("Username field is required!");
return false;
}
// check the other fields
// .....
}

May I suggest something like this instead:
HTML:
<form action="validateForm.html" onSubmit="return validateForm(this)">
<label for="username" name="usernameLabel">* Username:</label>
<input type="text" name="username" id="username" placeholder="Your username" />
<div id="usernameError" style="display:none"></div>
<br/><br/>
<label for="password" name="passwordLabel">* Password:</label>
<input type="password" name="password" />
<div id="passwordError" style="display:none"></div>
<br/><br/>
<input type="submit" value="Submit Form" />
</form>
JS:
function isEmpty (field) {
return field.value === "";
}
function validateForm (form) {
// assume the form to be valid
var isValid = true;
// create a variable to store any errors
var errors = "";
// check if the username is empty
if(isEmpty(form.username)) {
// our assumption is incorrect, the form is invalid
isValid = false;
// append the error message to the string
errors += "Username field is required!\n";
}
if (isEmpty(form.password)) {
isValid = false;
errors += "Password field is required!\n";
}
// display the errors if the form is invalid
if (!isValid) {
alert(errors);
}
return isValid;
}
This way, you are passing the form directly to the validateForm function and can easily access each field using their name properties. You can then check if they're empty by determining what their value contains.

If you need to get the DOM by it name means it will returns an Array so you need to get it by
if(!document.getElementsByName("username")[0].value == ""){
//do ur stuff
}
or
if(!document.getElementById("username").value == ""){
//do ur stuff
}

JavaScript Is Text Box Empty?

How can I check if a input field is empty in JavaScript when submitting the form?
html:
<input type="text" name="start_name" id="start_name">

Refer to http://www.w3schools.com/js/js_form_validation.asp
Have your form tag as
<form name="myForm" action="demo_form.asp" onsubmit="return validateForm()" method="post">
Next, have a javascript function
<script>
function validateForm()
{
var x=document.forms["myForm"]["start_name"].value;
if (x==null || x=="")
{
alert("Start name must be filled out");
return false;
}
}
</script>

var start_name = document.getElementById('start_name');
if( start_name.value.length > 0 ){
// Then there is something there.
}

Try.
<script type="text/javascript">
function checkme()
{
var inputVal = document.getElementById("start_name").value;
if(inputVal == "")
{
//code
}
}
</script>
<form action="" method="post" onSubmit = "checkme();">
<input type="text" name="start_name" id="start_name">
</form>

Just checking 'if (x==null || x=="")' is not enough to validate empty text box. Go for RegEx to check empty text box.
/^\s*[0-9a-zA-Z][0-9a-zA-Z ]*$/
Ensures that at least one character is not whitespace and is of one of the allowed characters.
Use /[a-z]/i as this regex will only match if there is at least one alphabetical character.

<form action="someActionUrl" onsubmit="return validate('first_name')">
<input id="first_name" name="first_name" />
</form>
<script>
function validate(inputId){
var val = document.getElementById(inputId).value;
if(val.length>0){
// do something
return true;
}
return false;
}
</script>

try this:
var x = document.getElementById("start_name");
if(x.value== "")
{
//your restriction code comes here
}
else
{
//go ahead!
}
Note: please check for syntax if its proper.i am writing the code here directly,haven't checked it on IDE.

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')