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ValidateForm How to validate and show text when submit button was clicked in JavaScript

I would like to show tick simple when the field is filled correctly, and show error message when it is not filled on each field.
I tried to make the code which using function validateForm, but it did not work. How do I fix the code? Please teach me where to fix.
Here is my html code
<form>
<div class="Form-Item">
<p class="Form-Item-Label"><span class="Form-Item-Label-Required">Required</span>Name</p>
<input type="text"id="name">
</div>
<div class="Form-Item">
<p class="Form-Item-Label"><span class="Form-Item-Label-Required" >Required</span>Number</p>
<input type="text" id="number">
</div>
<div class="Form-Item">
<p class="Form-Item-Label"><span class="Form-Item-Label-Required">Required</span>Mail address</p>
<input type="email">
</div>
<div class="Form-Item">
<p class="Form-Item-Label isMsg"><span class="Form-Item-Label-Required">Required</span>Message</p>
<textarea id="text"></textarea>
</div>
<input type="submit" value="submit">
<p id="log"></p>
</form>
Here is my JavaScript code
function validateForm(e) {
if (typeof e == 'undefined') e = window.event;
var name = U.$('name');
var number = U.$('number');
var email = U.$('email');
var text = U.$('text');
var error = false;
if (/^[A-Z \.\-']{2,20}$/i.test(name.value)) {
removeErrorMessage('name');
addCorrectMessage('name', '✔');
} else {
addErrorMessage('name', 'Please enter your name.');
error = true;
}
if (/\d{3}[ \-\.]?\d{3}[ \-\.]?\d{4}/.test(number.value)) {
removeErrorMessage('number');
addCorrectMessage('number', '✔');
} else {
addErrorMessage('number', 'Please enter your phone number.');
error = true;
}
if (/^[\w.-]+#[\w.-]+\.[A-Za-z]{2,6}$/.test(email.value)) {
removeErrorMessage('email');
addCorrectMessage('email', '✔');
} else {
addErrorMessage('email', 'Please enter your email address.');
error = true;
}
if (/^[A-Z \.\-']{2,20}$/i.test(text.value)) {
removeErrorMessage('text');
addCorrectMessage('text', '✔');
} else {
addErrorMessage('text', 'Please enter your enquiry.');
error = true;
}
if (error) {
if (e.preventDefault) {
e.preventDefault();
} else {
e.returnValue = false;
}
return false;
}
}
function addErrorMessage(id, msg) {
'use strict';
var elem = document.getElementById(id);
var newId = id + 'Error';
var span = document.getElementById(newId);
if (span) {
span.firstChild.value = msg;
} else {
span = document.createElement('span');
span.id = newId;
span.className = 'error';
span.appendChild(document.createTextNode(msg));
elem.parentNode.appendChild(span);
elem.previousSibling.className = 'error';
}
}
function addCorrectMessage(id, msg) {
'use strict';
var elem = document.getElementById(id);
var newId = id + 'Correct';
var span = document.getElementById(newId);
if (span) {
span.firstChild.value = msg;
} else {
span = document.createElement('span');
span.id = newId;
span.className = 'Correct';
span.appendChild(document.createTextNode(msg));
elem.parentNode.appendChild(span);
elem.previousSibling.className = 'Correct';
}
}
function removeErrorMessage(id) {
'use strict';
var span = document.getElementById(id + 'Error');
if (span) {
span.previousSibling.previousSibling.className = null;
span.parentNode.removeChild(span);
}
}
function removeCorrectMessage(id) {
'use strict';
var span = document.getElementById(id + 'Correct');
if (span) {
span.previousSibling.previousSibling.className = null;
span.parentNode.removeChild(span);
}
}

Using jQuery, you can use the .submit() event on a form element to conduct your own validation, note that you will have to preventDefault() to prevent the form submitting.
$("#myform").submit((e) => {
e.preventDefault(e);
// Validate name.
const name = $("#name").val();
if (name.length === 0) {
alert("Please provide a name!");
return;
}
alert("Success!");
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form id="myform">
<input type="text" id="name" placeholder="John Doe" />
<button type="submit">Submit</button>
</form>

which npm package do u use to validate ur data?.
If u use "validator" (link: https://www.npmjs.com/package/validator)
You can check if the field is filled correctly and send a check mark to the user.
for example if u wanted to check if data is an email
const validator = require("validator");
validator.isEmail('foo#bar.com');
if u want to see more about the options for the field just check the npm package page

Modern Browser support the Constraint Validation API which provides localized error messages.
Using this you can easily perform validation during basic events. For example:
// this will prevent the form from submit and print the keys and values to the console
document.getElementById("myForm").onsubmit = function(event) {
if (this.checkValidity()) {
[...new FormData(this).entries()].forEach(([key, value]) => console.log(`${key}: ${value}`);
event.preventDefault();
return false;
}
}
Would print all fields which would've been submitted to the console.
Or on an input field:
<input type="text" pattern="(foo|bar)" required oninput="this.parentNode.classList.toggle('valid', this.checkValidity());">
Will add the css class "valid" to the input field parent, if the value is foo or bar.
.valid {
border: 1px solid green;
}
.valid::after {
content: '✅'
}
<form oninput="this.querySelector('#submitButton').disabled = !this.checkValidity();" onsubmit="event.preventDefault(); console.log('Submit prevented but the form seems to be valid.'); return false;">
<fieldset>
<label for="newslettermail">E-Mail</label>
<!-- you could also define a more specific pattern on the email input since email would allow foo#bar as valid mail -->
<input type="email" id="newslettermail" oninput="this.parentNode.classList.toggle('valid', this.checkValidity());" required>
</fieldset>
<fieldset>
<input type="checkbox" id="newsletterAcceptTos" oninput="this.parentNode.classList.toggle('valid', this.checkValidity());" required>
<label for="newsletterAcceptTos">I accept the Terms of Service</label>
</fieldset>
<fieldset>
<label for="textFieldWithPattern">Enter <strong>foo</strong> or <strong>bar</strong></label>
<input type="text" id="textFieldWithPattern" pattern="^(foo|bar)$" required oninput="this.parentNode.classList.toggle('valid', this.checkValidity());" >
</fieldset>
<button type="submit" id="submitButton" disabled>Submit</button>
<button type="submit">Force submit (will show errors on invalid input)</button>
</form>

How trigger validation on a textbox when a button is pressed?

I've got two text boxes for first and last name. I also have a button to save the data. The button has an event handler where it grabs the data from the fields and posts them with an ajax call to my API, using jquery.
I want validation on my two textboxes (so they can't be left blank), but I don't know how to trigger that when my button is pressed. I am not using the <form> tag for this; I'm doing an ajax call when the button is pressed.

Here is an example which may help you:
$('#save').click(function() {
var errors = [];
var name = $('#name').val();
var vorname = $('#vorname').val();
if (!name) {
errors.push("Name can't be left blank");
}
if (!vorname) {
errors.push("Vorname can't be left blank");
}
if (errors.length == 0) {
console.log('Ajax started');
//put here your ajax function
} else {
for (var i in errors) {
console.log(errors[i]);
}
}
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input placeholder="Name" id="name"><br>
<input placeholder="Vorname" id="vorname"><br>
<button id="save">Save</button>

here is an example using the popular add on jquery validate. https://jqueryvalidation.org/
click the run snippet button below
$(document).ready(function() {
$("#form").validate({
rules: {
"firstname": {
required: true,
},
"lastname": {
required: true,
}
},
messages: {
"firstname": {
required: "Please, enter a first name"
},
"lastname": {
required: "Please, enter a last name"
},
},
submitHandler: function(form) { // for demo
alert('valid form submitted'); // for demo
return false; // for demo
}
});
});
body {
padding: 20px;
}
label {
display: block;
}
input.error {
border: 1px solid red;
}
label.error {
font-weight: normal;
color: red;
}
button {
display: block;
margin-top: 20px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.11.0/jquery.validate.min.js"></script>
<form id="form" method="post" action="#">
<label for="firstname">First Name</label>
<input type="text" name="firstname" id="firstname" />
<label for="lastname">Last Name</label>
<input type="text" name="lastname" id="lastname" />
<button type="submit">Submit</button>
</form>

Without seeing your code, it is very difficult to guess the correct scenario to provide examples for.
Given the following HTML:
<form>
<input type="text" class="text1">
<input type="text" class="text2">
<button type="button">Send</button>
</form>
You could use this for the jQuery part:
$('button').click(function() {
var txt1 = $(this).siblings('.text1').val();
var txt2 = $(this).siblings('.text2').val();
if (txt1.length && txt2.length) {
// do your ajaxy stuff here
} else {
alert("Imput some friggin' text!");
}
});
$(this) selects the button clicked.
.siblings('.text1') selects the input with class text1 inside the same block as the clicked button.
https://jsfiddle.net/sg1x0c3q/7/

As per my comments I would recommend using a form. But if you want a pure JS solution here you go. (if you want a form based solution just ask)
// convert all textareas into key value pairs (You can change the selector to be specific to your markup)
const createPayload = () => {
return [].slice.call(document.querySelectorAll('textarea')).reduce((collection, textarea) => ({
...collection,
[textarea.name]: textarea.value
}), {})
}
// Compare Object values against values that are not falsy (you could update the filter with a RegExp if you wanted more complicated validation)
const objectHasAllValues = obj => {
return Object.values(obj).length == Object.values(obj).filter(value => value).length
}
// If all key value pairs are not falsy then submit
window.submit = () => {
const payload = createPayload()
if (objectHasAllValues(payload)) {
fetch('/your/api', payload)
}
}
This solution presumes that your API expects a JSON payload. If you are expecting to send form data then you would need to use the formData js api.
This scales and doesn't need jQuery :)
Working example here https://jsfiddle.net/stwilz/dxg29mkj/28/

I want validation on my two textboxes (so they can't be left blank), but I don't know how to trigger that when my button is pressed. I am not using the <form> tag for this; I'm doing an ajax call when the button is pressed.
Answer to form validation. I assume that First name and Last name can only contain alphabets ,i.e., only a-z and A-Z.
//This function will trim extra whitespaces form input.
function trimInput(element){
$(element).val($(element).val().replace(/\s+/g, " ").trim());
}
//This function will check if the name is empty
function isEmpty(s){
var valid = /\S+/.test(s);
return valid;
}
//This function will validate name.
function isName(name){
var valid = /^[a-zA-Z]*$/.test(name);
return valid;
}
$('#myForm').submit(function(e){
e.preventDefault();
var fname = $(this).find('input[name="fname"]');
var lname = $(this).find('input[name="lname"]');
var flag = true;
trimInput(fname);
trimInput(lname);
if(isEmpty($(fname).val()) === false || isName($(fname).val()) === false){
alert("First name is invalid.");
flag = false;
}
if(isEmpty($(lname).val()) === false || isName($(lname).val()) === false){
alert("Last name is invalid.");
flag = false;
}
if(flag){
alert("Everything is Okay");
//Code to POST form data goes here...
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form name="myform" id="myForm" method="post" action="#">
<input type="text" name="fname" placeholder="Firstname">
<input type="text" name="lname" placeholder="Last Name">
<input type="submit" name="submit" value="Submit">
</form>
I am not using the <form> tag for this.
Then the code will be like
//This function will trim extra whitespaces form input.
function trimInput(element) {
$(element).val($(element).val().replace(/\s+/g, " ").trim());
}
//This function will check if the name is empty
function isEmpty(s) {
var valid = /\S+/.test(s);
return valid;
}
//This function will validate name.
function isName(name) {
var valid = /^[a-zA-Z]*$/.test(name);
return valid;
}
$('#submit').click(function() {
var fname = $('#fname');
var lname = $('#lname');
var flag = true;
trimInput(fname);
trimInput(lname);
if (isEmpty($(fname).val()) === false || isName($(fname).val()) === false) {
alert("First name is invalid.");
flag = false;
}
if (isEmpty($(lname).val()) === false || isName($(lname).val()) === false) {
alert("Last name is invalid.");
flag = false;
}
if (flag) {
alert("Everything is Okay");
//Code to POST form data goes here...
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" id="fname" name="fname" placeholder="Firstname">
<input type="text" id="lname" name="lname" placeholder="Last Name">
<button type="button" id="submit" name="submit">Submit</button>
Check the code on jsFiddle.
Hope this will be helpful.

JavaScript Email address validation

I am making an HTML form with fields validation using JavaScript. I am stuck on email validation. I searched internet and found something like this-
JS Code
function validateemail() {
var x=document.myform.email.value;
var atposition=x.indexOf("#");
var dotposition=x.lastIndexOf(".");
if (atposition<1 || dotposition<atposition+2 || dotposition+2>=x.length) {
alert("Please enter a valid e-mail address \n atpostion:"+atposition+"\n dotposition:"+dotposition);
return false;
}
}
HTML Code
<body>
<form name="myform" method="post" action="#" onsubmit="return validateemail();">
Email: <input type="text" name="email"><br/>
<input type="submit" value="register">
</form>
Please explain me this?

Check this i am using something like this i minified some of them
You must Enter Valid Email address something like this Example#example.com
$(document).ready(function() {
$('.insidedivinput').focusout(function() {
$('.insidedivinput').filter(function() {
var emil = $('.insidedivinput').val();
var emailReg = /^([\w-\.]+#([\w-]+\.)+[\w-]{2,4})?$/;
if (emil.length == 0) {
$('.fa-check').css('display', 'none');
$('.fa-close').css('display', 'inline');
$('.sendmailbuttontrigger').attr('disabled', 'disabled');
$('.SendEmail').attr('disabled', 'disabled');
} else if (!emailReg.test(emil)) {
$('.SendEmail').attr('disabled', 'disabled');
$('.sendmailbuttontrigger').attr('disabled', 'disabled');
$('.fa-check').css('display', 'none');
$('.fa-close').css('display', 'inline');
} else {
// alert('Thank you for your valid email');
$('.fa-close').css('display', 'none');
$('.sendmailbuttontrigger').removeAttr('disabled');
$('.fa-check').css('display', 'inline');
}
})
});
});
.fa-check{
display:none;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type='email' class='insidedivinput'><i class='fa-check'>Validated</i><i class="fa-close">UnValidated</i>
<button class="sendmailbuttontrigger" disabled>
Send
</button>

If you just want to validate an email address, you can use the validation that's built into HTML:
<form onsubmit="return false;">
<input type="email" required="1">
<input type="submit">
</form>
(Leave out the onsubmit for your own form, of course. It's only in my example to keep you from leaving the page with the form.)

I also searched on the Internet and use this one and it's working.
// email validation
checkEmail = (inputvalue) => {
const pattern = /^([a-zA-Z0-9_.-])+#([a-zA-Z0-9_.-])+\.([a-zA-Z])+([a-zA-Z])+/;
if (pattern.test(inputvalue)) return true;
return false;
}

OnBlur Validation Requires Onsubmit Button to Be Clicked Twice in Pure Javascript

I have a form which validates password null/blank or not using onblur. And I use a submit button to submit the form. However the submit button needs to be clicked twice before to work. It does not work on the first click after something has been filled in the password box. Below is the code.
With respect to Jquery, I require solution in pure Javascript.
I have tried onkeyup, but that is not a good solution as it will put strain on system, and server (for ajax).
<!DOCTYPE html>
<html>
<body>
<script>
var error_user_password = false;
function checkpw(){
var user_password = document.forms["joinform"]["user_password"].value;
if (user_password == null || user_password == "") {
text = "Password : Required";
document.getElementById("errormsg4").innerHTML = text;
error_user_password = false;
} else {
document.getElementById("errormsg4").innerHTML = "";
error_user_password = true;
}
}
function submitall() {
checkpw()
if(error_user_password == false) {
return false;
} else {
return true
}
}
</script>
</body>
<form id="joinform" method="post" name="joinform" action="#hello" onsubmit="return submitall()" >
<h2>Join</h2>
<input type="password" name="user_password" id="user_password" placeholder="Password" onblur="checkpw()" />
<div class ="errormsg" id ="errormsg4"></div><br>
<input type="submit" name="join" id="join" value="Submit" ><br><br>
</form>
</html>

OnBlur Validation Requires Onsubmit Button to Be Clicked Twice in Pure Javascript
This happens because the blur event is captured from the onblur event handler and not bubbled to the form submit button.
A full javaScript solution is based on:
addEventListener
activeElement: inside the blur event I check after 10 milliseconds if the submit button get the focus.
My snippet:
var error_user_password = false;
function checkpw(ele, e){
var user_password = document.forms["joinform"]["user_password"].value;
if (user_password == null || user_password == "") {
text = "Password : Required";
document.getElementById("errormsg4").innerHTML = text;
error_user_password = false;
} else {
document.getElementById("errormsg4").innerHTML = "";
error_user_password = true;
}
}
function submitall(ele, e) {
checkpw();
if(error_user_password == false) {
e.preventDefault();
} else {
console.log('form submitted');
}
}
window.addEventListener('DOMContentLoaded', function(e) {
document.getElementById('user_password').addEventListener('blur', function(e) {
checkpw(this, e);
setTimeout(function() {
if (document.activeElement.id == 'join') {
document.activeElement.click();
}
}, 10);
}, false);
document.getElementById('joinform').addEventListener('submit', function(e) {
submitall(this, e);
}, false);
});
<form id="joinform" method="post" name="joinform" action="#hello">
<h2>Join</h2>
<input type="password" name="user_password" id="user_password" placeholder="Password"/>
<div class ="errormsg" id ="errormsg4"></div><br>
<input type="submit" name="join" id="join" value="Submit" ><br><br>
</form>

Validation with JavaScript

There are similar questions, but I can't find the way I want to check the form submit data.
I like to check the form submit data for phone number and email. I check as follows, but it doesn't work.
How can I make it correct?
<script>
function validateForm() {
var x = document.forms["registerForm"]["Email"].value;
if (x == null || x == "") {
alert("Email number must be filled out.");
return false;
}
else if(!/#./.test(x)) {
alert("Email number must be in correct format.");
return false;
}
x = document.forms["registerForm"]["Phone"].value;
if (x == null || x == "" ) {
alert("Phone number must be filled out.");
return false;
}
else if(!/[0-9]+()-/.test(x)) {
alert("Phone number must be in correct format.");
return false;
}
}
</script>
For email I'd like to check only "#" and "." are included in the email address.
For phone number, I'd like to check ()-+[0-9] and one space are only accepted for phone number, for example +95 9023222, +95-1-09098098, (95) 902321. How can I check it?
There will be another check at the server, so there isn't any need to check in detail at form submit.

Email validation
From http://www.w3resource.com/javascript/form/email-validation.php
function ValidateEmail(mail)
{
if (/^\w+([\.-]?\w+)*#\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(myForm.emailAddr.value))
{
return (true)
}
alert("You have entered an invalid email address!")
return (false)
}
Phone number validation
From http://www.w3resource.com/javascript/form/phone-no-validation.php.
function phonenumber(inputtxt)
{
var phoneno = /^\d{10}$/;
if ((inputtxt.value.match(phoneno))
{
return true;
}
else
{
alert("message");
return false;
}
}

You can do something like this:
HTML part
<div class="form_box">
<div class="input_box">
<input maxlength="64" type="text" placeholder="Email*" name="email" id="email" />
<div id="email-error" class="error-box"></div>
</div>
<div class="clear"></div>
</div>
<div class="form_box">
<div class="input_box ">
<input maxlength="10" type="text" placeholder="Phone*" name="phone" id="phone" />
<div id="phone-error" class="error-box"></div>
</div>
<div class="clear"></div>
</div>
Your script
var email = $('#email').val();
var phone = $('#phone').val();
var email_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]{2,3}))$/;
var mobile_re = /^[0-9]{10}$/g;
if ($.trim(email) == '') {
$('#email').val('');
$('#email-error').css('display', 'block');
$('#email-error').html('Please enter your Email');
} else if (!email.match(email_re)) {
$('#email-error').css('display', 'block');
$('#email-error').html('Please enter valid Email');
}
if ($.trim(phone) == '') {
$('#phone').val('');
$('#phone-error').css('display', 'block');
$('#phone-error').html('Please enter your Phone Number');
} else if (!phone.match(mobile_re)) {
$('#phone-error').css('display', 'block');
$('#phone-error').html('Please enter valid Phone Number');
} else {
$('#phone-error').css('display', 'none');
$('#phone-error').html('');
}

You could of course write the validation part yourself, but you could also use one of the many validation libraries.
One widely used one is Parsley. It's very easy to use. Just include the .js and .css and add some information to the form and its elements like this (fiddle):
<script src="jquery.js"></script>
<script src="parsley.min.js"></script>
<form data-parsley-validate>
<input data-parsley-type="email" name="email"/>
</form>

HTML5 has an email validation facility. You can check if you are using HTML5:
<form>
<input type="email" placeholder="me#example.com">
<input type="submit">
</form>
Also, for another option, you can check this example.