We Keep Coding

How to check if there is no validation error exist in webpage using jquery?

I am trying to check if all form fields are filled on click a button & if valid then i am trying to add a check an alert using jquery.
jQuery("button#btn_place_order").click(function(event){
jQuery("form").validate({
submitHandler: function(form) {
alert('ok');
}
});
});
This is what i have tried but its not working, i just want to check if all fields are ok valid & filled & there is no form related error then just console or alert to check. Webpage has two or more html forms. Is their any way we can check using jquery ?
Thanks

First of you will have to prevent the default behavior of a form submit. Afterwards add a event listener to your button and check for validation of each input. (whatever that means for you). Is this what you wanted?
var el = document.getElementById("form");
el.addEventListener("submit", function(event) {
event.preventDefault();
}, true);
document.getElementById("btn").addEventListener("click", validate);
function validate(){
let valid = true;
[...document.getElementById("form").elements].forEach((input) => {
if(input.value.length == 0){
valid = false;
}
});
if(valid) alert("valid");
}
<form id="form">
<input type="text" name="TEST" id="test">
</form>
<button class="button" name="Send" value="Send" id="btn">Check</button>

Prevent action attribute from running php script with javascript [duplicate]

This question already has answers here:
prevent form from POSTing until javascript code is satisfied
(4 answers)
Closed 9 years ago.
Is there a way that I can use javascript to prevent a form from runing a php script. For example something like this:
<form action="somePage.php" method="POST>
<input type= "text" class= "field" name = "blah">
<input type="submit" value="Send" >
</form>
I know how to validate what's in that text box using javascript, but I want to prevent the somePage.php to run if the text box is empty. I haven't really tried anything cause I just don't know how to do it.
Hope you guys understand my problem.
Thanks

You can attach function to submit event of the form:
document.getElementById('form-id').addEventListener("submit", function(e){
var field1 = getElementById('field1').value;
if(field1=='' || field1 == null){
e.preventDefault();
alert('Pls fill the required fields.');
return;
}
return true;
});
OR
Below solution uses inline js:
If you want to run your js function before submitting the form to php script, you can use onsubmit attribute of the form,
<form id="form-id" action="somePage.php" method="POST" onsubmit="return formSubmit();">
<input type= "text" class= "field" id="field1" name = "blah">
<input type="submit" value="Send" >
</form>
In formSubmit function you can check the value of the input, if its empty or not, and if empty, then you can just return false;
var formSubmit = function(){
var field1 = getElementById('field1').value;
if(field1=='' || field1 == null)
return false;
else
return true;
}

You simply need to return false for your submit event by grabbing the form (I used querySelector because you have no IDs or classes), and adding a submit listening event to return false.
var x = document.querySelector("[method='POST']");
x.addEventListener("submit",function() {
return false;
});

Use this code to prevent form from submitting:
var first_form = document.getElementsByTagName('form')[0];
first_form.addEventListener('submit', function (e) {
e.preventDefault(); //This actually prevent browser default behaviour
alert('Don\'t submit');
//Do your stuff here
}, false);
Better read docs

you could in your somePage.php have this be a clause somewhere new the beggin:
if(empty($_POST['blah'])){
die();
}
or the inverse of
if(!empty($_POST['blah'])){
//do what this php is supposed to
}
else{
//display error
}
this will prevent your php from running if that field is not filled out.
Personally I return them to the same page setting some error on the page.

Avoid page submission on button click if condition false in javascript

I am checking the textbox value in javascript. and saving to database. where as my save is of submit type. I want if textbox value is greater than 100 then it should alert. and after alert , page should not submit.

Firstly, bind the click event of that button to a function. Secondly, use event.prevent default to stop that button from submitting the form. Thirdly, validate the value you want. If validated, use form id to submit the form. Something like this:
$("#ButtonId").on("click", function(event) {
event.preventDefault ? event.preventDefault() : event.returnValue = false;
if ($("#InputBoxID").val() < 100) {
$("#FormId").submit();
}
else {
alert("your message");
}
});
Above code is in jQuery, so do not forget to add the reference to jQuery.

I think you're looking for something like:
<form id="myForm" onsubmit="return validateForm();">
<input type="text" id="textfield"/>
<button type="submit">submit</button>
</form>
<script>
function validateForm(){
var value=parseInt(document.getElementById('textfield').value);
if(value>100){
alert('value is no good. larger then 100');
return false;
}
}
</script>
If you can show me your code I'd be happy to help you implementing such a feature.

Here you have an example of how to do it. I used a limit of 10 characters to make the test easier: Try if yourself
HTML:
<input type="text" id="myTextBox" onkeyup="checkValue(this)" maxlength="10"></input>
<input id="sendButton" type="submit" value="SEND"></inpu
JAVASCRIPT:
function checkValue(textbox) {
if (textbox.value.length > 10) {
alert("TEXT TOO LONG");
document.getElementById("sendButton").disabled = true;
}
else
document.getElementById("sendButton").disabled = false;
}

Displaying an image after pressing submit html

I have the following code to display an image after i press submit
<img id="image1" src="images/Coverflow1.jpg" style="display:none;"/>
<input type="submit" name="submit" value="submit" onclick="$('#image1').show()"/>
Name is retrieved by
var y=document.forms["myForm"]["fname"].value;
Where fname is
<h4>Name: <input type="text" name="fname" size="61" /></h4>
Only problem is this is using Jquery, so I can't seem to pass it through any of my other
validations like checking if the name field is null.
if (name==null || name=="")
{
alert("First name must be filled out");
return false;
}
Is there a Javascript equivalent to this that I can stick in my else statement so it will only show it if the form actually submits properly passing the validation checks beforehand?
Thanks

do all that in jquery.
if (name==null || name=="")
{
alert("First name must be filled out");
return false;
}
else
{
$('#image1').show()
}

You should be using the .submit() event handler of jQuery instead of attaching an onclick property to the submit button. The onclick property will not fire its function in the event that a user submits the form via the enter key; however, the .submit() method will capture it as well.
$("form[name=myForm]").submit(function(e) {
//get value of name here.
var name = this.fname.value; //this refers to the form, because that is what is being submitted.
//Do validation.
if (name == null || name == "") {
//If failed, then prevent the form from submitting.
alert("First name must be filled out.");
e.preventDefault();
return;
}
//If validation passed, show image.
$("#image1").show();
});

First, remove the onclick attribute from the submit button:
<img id="image1" src="images/Coverflow1.jpg" style="display:none;"/>
<input type="submit" name="submit" value="submit" />
Since you're using jQuery, attaching handlers to click events in JavaScript is a snap (and it's also a good practice).
I almost always use the following pattern for form validation (and on the submit of the form, rather than the click of the submit button because there are other ways to submit forms than clicking the button).
$(document).ready(function () {
var formIsValid = function formIsValid () {
// your validation routines go here
// return a single boolean for pass/fail validations
var name =document.forms.myForm.fname.value;
return !!name; // will convert falsy values (like null and '') to false and truthy values (like 'fred') to true.
};
$('form').submit(function (e) {
var allGood = formIsValid();
if (!allGood) {
e.preventDefault();
}
$('#image1').toggle(allGood); // hide if validation failed, show if passed.
return allGood; // stops propagation and prevents form submission if false.
});
});

Clear an input field after submission using JavaScript

I am a JavaScript newbie. I have an input text field that I wish to clear after pressing the form submit button. How would I do that?

In your FORM element, you need to override the onsubmit event with a JavaScript function and return true.
<script type="text/javascript">
function onFormSubmit ()
{
document.myform.someInput.value = "";
return true; // allow form submission to continue
}
</script>
<form name="myform" method="post" action="someaction.php" onsubmit="return onFormSubmit()">
<!-- form elements -->
</form>

If a user presses the submitbutton on a form the data will be submitted to the script given in the action attribute of the form. This means that the user navigates away from the site. After a refresh (assuming that the action of the form is the same as the source) the input field will be empty (given that it was empty in the first place).
If you are submitting the data through javascript and are not reloading the page, make sure that you execute Nick's code after you've submitted the data.
Hope this is clear (although I doubt it, my English is quite bad sometimes)..

function testSubmit()
{
var x = document.forms["myForm"]["input1"];
var y = document.forms["myForm"]["input2"];
if (x.value === "")
{
alert('plz fill!!');
return false;
}
if(y.value === "")
{
alert('plz fill the!!');
return false;
}
return true;
}
function submitForm()
{
if (testSubmit())
{
document.forms["myForm"].submit(); //first submit
document.forms["myForm"].reset(); //and then reset the form values
}
}
First Name: <input type="text" name="input1"/>
<br/>
Last Name: <input type="text" name="input2"/>
<br/>
<input type="button" value="Submit" onclick="submitForm()"/>
</form>

After successfully submitting or updating form or password you can put empty value.
CurrentPasswordcontroller.state.confirmPassword = '';