We Keep Coding

preventDefault() cause problem on validating the form

the code below was written to validate simple html form with JavaScript and preventDefault() method means that if the required fields are empty then stop form submission and display error or otherwise submit the form if the required fields are not empty.
The problem comes when I click the submit button the form isn't working.
Can anyone please help me to solve the problem?
let form = document.getElementById("signUp");
let uname = document.forms["myForm"]["userName"].value;
let uemail = document.forms["myForm"]["userEmail"].value;
function validateForm() {
if (uname == " ") {
alert("Name is Empty");
} else if (uemail == " ") {
alert("Email is Empty");
return false;
}
return true;
}
form.addEventListener("submit", function(e) {
e.preventDefault();
validateForm();
});
<form id="signUp" name="myForm">
Name: <input type="text" name="uname" id="userName">
<br> Email: <input type="email" name="email" id="userEmail">
<button type="submit">sign up</button>
</form>

With e.preventDefault() you say that the form should not be submitted.
So you only want to call if in case the validation returns false.
Besides that, your uname and uemail is set before the form is submitted. So it won't contain the state of the input fields at the time the form is submitted. You have to move them into your validateForm function.
let form = document.getElementById("signUp");
function validateForm() {
let uname = document.forms["myForm"]["userName"].value;
let uemail = document.forms["myForm"]["userEmail"].value;
if (uname == " ") {
alert("Name is Empty");
} else if (uemail == " ") {
alert("Email is Empty");
return false;
}
return true;
}
form.addEventListener("submit", function(e) {
if (!validateForm()) {
e.preventDefault();
}
});
<form id="signUp" name="myForm">
Name: <input type="text" name="uname" id="userName">
<br> Email: <input type="email" name="email" id="userEmail">
<button type="submit">sign up</button>
</form>
And uname == " " does not test if the name is empty. It tests if it consists of one character that is a space. The same is for uemail == " ". You probably looking for uname.trim() == ""
As you need to verify the data on the server anyways. And in some way need to display an error if the validation fails on the server side.
It is often sufficient to rely on the HTML solutions to verify the form data (if the browser support is decent enough even if it is not complete).
Something like this:
.error {
display: none;
}
input:not(:placeholder-shown):invalid +.error {
display: block;
}
<form id="signUp" name="myForm">
Name: <input type="text" name="uname" id="userName" placeholder="Name" pattern="^(?!^ +$)([\w -&]+)$" required>
<div class="error">Name must not be empty</div>
<br> Email: <input type="email" name="email" id="userEmail" placeholder="Email" required>
<div class="error">Email must be valid</div>
<button type="submit">sign up</button>
</form>

const form = document.getElementById("signUp");
form.addEventListener("submit", (e) => {
e.preventDefault();
if(validate()) {
form.submit()
}
});
const validate = () => {
const name = document.querySelector("#userName");
const email = document.querySelector("#email");
let hasError = false;
if(!(name.value && name.value.length > 4)) {
const nameErr = document.querySelector("#user-name-error");
nameErr.textContent = "Name is required";
hasError = true;
}
if(!(name.value && name.value.length > 0)) {
const emailErr = document.querySelector("#user-email-error");
emailErr.textContent = "Email is required";
hasError = true;
}
return !hasError;
};
<form id="signUp" name="myForm">
<div class="form-group">
<label for="userName">Name: </label>
<input type="text" name="uname" id="userName" />
<p id="user-name-error" style="color: red;"></p>
</div>
<div class="form-group">
<label for="userEmail">Email: </label>
<input type="email" name="email" id="email" />
<p id="user-email-error" style="color: red;"></p>
</div>
<button type="submit">sign up</button>
</form>

<form id="signUp" name="myForm">
<div class="form-group">
<label for="userName">Name: </label>
<input type="text" name="uname" id="userName" required minlength="4"/>
</div>
<div class="form-group">
<label for="userEmail">Email: </label>
<input type="email" name="email" id="email" required pattern="[^#]*#[^.]*\..*"/>
</div>
<button type="submit">sign up</button>
</form>
This is an example using only html, it is only for your use case of course if you want to add more complexe validation use javascript

Form Validation in JQuery Mobile

I'm trying to add validation to the form I made
<fieldset>
<legend>ENTER YOUR INFORMATION HERE FOR DELIVERY</legend>
<form action="" name="deliveryform">
Name* :<input type="text" name="name" id="name">
Phone Number* : <input type="text" name="phonenumber" id="phonenumber">
<span id="warning1"></span>
Address* : <textarea name="address" id="address" required></textarea>
Email* : <input type="text" name="email" id="email">
<span id="warning2"></span>
<input type="submit" id="submitbutton" value="Submit" onsubmit=" return validation()">
</form>
</fieldset>
Javascript
function validation()
{
var name = document.getElementsByName("name").value;
var phonenumber =document.getElementsByName("phonenumber").value;
var email = document.getElementById("email").value;
var emailformat = "[a-z0-9._%+-]+#[a-z0-9.-]+\.[a-z]{2,}$";
if(name == ""|| null)
{
alert("Please Enter Your Name!");
return false;
}
if(isNaN (phonenumber))
{
document.getElementById("warning1").innerHTML ="Enter numbers only";
return false;
}
if(!email.match(emailformat))
{
document.getElementById("warning2").innerHTML="Please enter the correct format. Example : Abc1234#gmail.com"
return false;
}
else
{
alert("Submitted Successfully")
}
}
Nothing changed except ''Error Loading Page '' message appeared.
Did I miss something?
I thought coding in without and with Jquery in HTML is the same thing..

Email and mobile number validation on same html5 textbox with button

I want to validate both email,mobile number using single textbox.
I tried in many ways but not working. i want to validate either it is javascript,html5,jquery,angularjs is not a problem.
please help me to solve this problem. thanks in advance
http://jsfiddle.net/ANxmv/3582/
<form name="form" ng-app="app" ng-controller="Ctrl" >
<div class="control-group" ng-class="{true: 'error'}[submitted && form.email.$invalid]">
<label class="control-label" for="email">Your email address/Mobile number</label>
<div class="controls">
<input type="email" name="email" ng-model="email" required />
</div>
</div>
<button type="submit" class="btn btn-primary btn-large" ng-click="submitted=true">Submit</button>
</form>

here is the simple javascript code which will validate both email and phone number.
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<script>
function ValidateEmail(mail)
{
var mailformat = /^\w+([\.-]?\w+)*#\w+([\.-]?\w+)*(\.\w{2,3})+$/;
// if (/^\w+([\.-]?\w+)*#\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(myForm.emailAddr.value))
if(mail.match(mailformat))
{ alert(mail);
return (true)
}
alert("You have entered an invalid email address!")
return (false)
}
function validate()
{
var data=document.getElementById("email").value;
checkNumberorEmail();
}
function phonenumber(inputtxt)
{
var phoneno = /^\d{10}$/;
if((inputtxt.match(phoneno)))
{
alert(inputtxt);
return true;
}
else
{
alert("enter 10 digit number");
return false;
}
}
function checkNumberorEmail()
{
var data=document.getElementById("email").value;
if (isNaN(data))
{
ValidateEmail(data) ;
}
else{
phonenumber(data)
}
}
</script>
</head>
<body>
<form >
<input type="text" name="email" id="email">
<input type="button" onclick="validate()">
</form>
</body>
</html>
FIDDLE

The method itself is not good. But here is a possible simple function in angular js
HTML
<form name="form" ng-app="app" ng-controller="Ctrl" >
<div class="control-group" ng-class="{invalidClass: 'error'}[submitted && form.email.$invalid]">
<label class="control-label" for="email">Your email address/Mobile number</label>
<div class="controls">
<input type="text" name="email" ng-model="email" required />
</div>
</div>
<button type="submit" class="btn btn-primary btn-large" ng-click="submitForm()">Submit</button></form>
Controller
$scope.submitForm = function(){
if(validateEmail($scope.email) || validateMobile($scope.email)){
// The nput is email or mobile
}
else{
//both are not valid
console.log("Invalid inputs");
$scope.invalidClass = true;
}
}
function validateEmail(email) {
var re = /^(([^<>()[\]\\.,;:\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,}))$/;
return re.test(email);
}
function validateMobile(email) {
var re = /^\d{10}$/;
return re.test(email);
}

Adding a node to html page with javascript

This is my first time with javascript. I'm making a basic login page where there is a control for the email input. I would like to put an error message of some kind when someone gives an email address with illegal symbol. Here my code:
<!DOCTYPE html>
<html>
<head>
<title>Home</title>
<meta charset="UTF-8">
</head>
<body>
<div>
<form action="Home.html" method="post">
<label for="id">Username</label>
<input type="text" name="id" id="id" value="" />
<br/>
<label for="pass">Password</label>
<input type="password" name="pass" id="pass" value="" />
<br/>
<label for="email">Email</label>
<input type="email" name="email" id="email" value="" />
<br/>
<script type="text/javascript">
function checkEmail ()
{
var emailObject = document.getElementById("email");
var email = emailObject.getAttribute("value").toString();
var error = document.createTextNode("Uncorrect email");
var result = email.search("/[^(a-z | A-Z | 0-9 | #)]/");
if(result !== -1)
{
emailObject.appendChild(error);
}
}
</script>
<button type="button" onclick="checkEmail()"> Confirm </button>
</form>
</div>
</body>
</html>

I have a function I use to validate email addresses, it uses regex. I would suggest jQuery just to show/hide the error message.
function validEmail(val){
if(val.length < 6 || val.length > 255) return false;
return new RegExp(/^[a-zA-Z0-9._-]+#[a-zA-Z0-9.-]+\.[a-zA-Z]{2,6}$/).test(val);
}
$(function(){
$("#email").on("change", function(){
var email = $("#email").val();
if(!validEmail(email)){
$("#emailError").show();
} else {
$("#emailError").hide();
}
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form>
<!-- Some Inputs here -->
<span id='emailError' style='display: none;'>Please enter a valid email address</span><br>
<input type='email' id='email' name='email' placeholder='Email Address' />
<!-- More Inputs here -->
<button type='submit'>Submit</button>
</form>

you're trying to append something to an input element (email input, in this case). I'd suggest to append it to your main div, which in this case I have identified as "YOUR_ID".
Also, I suggest you a more efficint way to check a valid email.
follow the below example
<body>
<div id="YOUR_ID">
<form action="Home.html" method="post">
<label for="id">Username</label>
<input type="text" name="id" id="id" value="" />
<br/>
<label for="pass">Password</label>
<input type="password" name="pass" id="pass" value="" />
<br/>
<label for="email">Email</label>
<input type="email" name="email" id="email" value="" />
<br/>
<script type="text/javascript">
function checkEmail ()
{
var emailObject = document.getElementById("email");
var divObject = document.getElementById("YOUR_ID");
var email = emailObject.getAttribute("value").toString();
var error = document.createTextNode("Uncorrect email");
var check = /^([\w-]+(?:\.[\w-]+)*)#((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i;
var result = check.test(email);
if(result !== -1)
{
divObject.appendChild(error);
}
}
</script>
<button type="button" onclick="checkEmail()"> Confirm </button>
</form>
</div>
</body>

using id="submit" twice on one page

I am creating a login/register part to a site. And the login and register forms are on page.
Like:
<form name="loginform" style="text-align:center;" method="post" onsubmit="return validateForm();" action="index.php">
<div class="row">
<input type="text" name="email" id="email" autocomplete="off" placeholder="Email Address" />
</div>
<br />
<div class="row">
<input type="password" name="password" id="password" autocomplete="off" placeholder="Password" />
</div>
<br />
<div class="row">
<button id="submit" type="submit" class="button large arrow-type-2 dark">Log Me In</button>
</div>
</form>
<form name="registerform" style="text-align:center;" method="post" onsubmit="return validatethisForm();" action="index.php">
<div class="row">
<input type="text" name="email" id="email2" autocomplete="off" placeholder="Email Address"/>
</div>
<br />
<div class="row">
<input type="password" name="password" id="password2" autocomplete="off" placeholder="Password"/>
</div>
<br />
<div class="row">
<button id="submit" type="submit" class="button large arrow-type-2 dark">Create Free Account</button>
</div>
</form>
My Js Validation is: ( needs work )
function validateForm()
{
var x=document.forms["loginform"]["email"].value;
var atpos=x.indexOf("#");
var dotpos=x.lastIndexOf(".");
if (atpos<1 || dotpos<atpos+2 || dotpos+2>=x.length)
{
alert("Not a valid e-mail address");
return false;
}
var x=document.forms["loginform"]["password"].value;
if (x==null || x=="")
{
alert("Please enter a Password");
return false;
}
}
function validatethisForm()
{
var x=document.forms["registerform"]["email2"].value;
var atpos=x.indexOf("#");
var dotpos=x.lastIndexOf(".");
if (atpos<1 || dotpos<atpos+2 || dotpos+2>=x.length)
{
alert("Not a valid e-mail address");
return false;
}
var x=document.forms["registerform"]["password2"].value;
if (x==null || x=="")
{
alert("Please enter a Password");
return false;
}
}
The issue I have is page validation, everything works perfect. But because I have duplicate submit id's , I need to clean this up.
Can you offer suggestions on improving my code above ?
/////////////////////////////////////////
Using: code below for cross browser placeholder
$('[placeholder]').focus(function() {
var input = $(this);
if (input.val() == input.attr('placeholder')) {
input.val('');
input.removeClass('placeholder');
}
}).blur(function() {
var input = $(this);
if (input.val() == '' || input.val() == input.attr('placeholder')) {
input.addClass('placeholder');
input.val(input.attr('placeholder'));
}
}).blur().parents('form').submit(function() {
$(this).find('[placeholder]').each(function() {
var input = $(this);
if (input.val() == input.attr('placeholder')) {
input.val('');
}
})
});

I simplified your HTML code to the following:
<form name="loginForm" method="post" onsubmit="return validateForm();" action="index.php">
<label>Email Address: <input type="email" name="email" autocomplete="off" placeholder="Email Address"/></label>
<label>Password: <input type="password" name="password" placeholder="Password"/></label>
<button type="submit" class="button large arrow-type-2 dark">Log In</button>
</form>
<form name="registerForm" method="post" onsubmit="return validatethisForm();"
action="index.php">
<label>Email Address: <input type="email" name="email" autocomplete="off" placeholder="Email Address"/></label>
<label>Password: <input type="password" name="password" placeholder="Password"/></label>
<button type="submit" class="button large arrow-type-2 dark">Create Free Account</button>
</form>
Points
Always include a label. Not all browsers support HTML5 placeholders.
All IDs here are reluctant. Forms can be accessed by
var loginForm = document.forms.loginForm; //By name
and form elements by
loginForm.email; //Also by name
No need for divs and brs to manage the line breaks. Use the labels themselves. Add display: block; as necessary.
Don't use inline style attribute. Use a CSS <style> element or an external stylesheet.
There's no AutoComplete on password fields.
Use HTML5's new form input types. type="email" will have the browser natively validate the field and notify the user if the email is not valid.
Keep it simple. No need for bloating.

Since both functions do the same thing, just make one function and bind it to both forms 'onsubmit' event.
You taggued is as jquery ,so, jquery-style, using Mike Alsup's jQuery Form Plugin.
function validate(formData, jqForm, options) {
// formData is an array of objects representing the name and value of each field
// that will be sent to the server; it takes the following form:
//
// [
// { name: username, value: valueOfUsernameInput },
// { name: password, value: valueOfPasswordInput }
// ]
//
// To validate, we can examine the contents of this array to see if the
// username and password fields have values. If either value evaluates
// to false then we return false from this method.
for (var i=0; i < formData.length; i++) {
if (!formData[i].value) {
alert('Please enter a value for both Username and Password');
return false;
}
}
alert('Both fields contain values.');
}
$('form').ajaxForm( { beforeSubmit: validate } );
This example and more info here.