We Keep Coding

How to know required field validation triggered or not? [duplicate]

This question already has answers here:
JavaScript validation for empty input field
(15 answers)
Closed 3 years ago.
I have a big form with lot of fields and most of them are required fields. so i wanted to show pop-up alert message saying please fill required field.
<input name="fname" id="fname" type="text" class="form-control" required>
also i m showing usual message below that particular field,
i need something like on submit click
If (some fields required field error got triggered )
{
show alert pop-up message ;
}
I am new to this thing so..

function checkEmpty()
{
var fname = document.getElementById('fname').value;
if(!fname)
{
alert('Field is empty')
}
}
<form onsubmit='checkEmpty'>
<!--Form contents-->
</form>
Validation with javscript can easily be bypassed since it happens in the client side.

Try this
<form onsubmit="myFunction()">
<input name="fname" id="fname" type="text" class="form-control" required>
<form>
Use the following Function to check fields
function myFunction() {
var fname=document.getElementById('fname').value;
if(!fname)
{
alert("please fill required field");
}
}
You can check multiple fields in if conditions by putting || Sign. eg you have 2 filed fname and lname. You can check by if(!fname || !name)

You need to show overall alert as well as individual error message below each required field.
To do so using jQuery,
<form>
<input name="fname" id="fname" type="text" class="form-control validateclass" required>
<span class="spnError"></span>
<input name="lname" id="lname" type="text" class="form-control validateclass" required>
<span class="spnError"></span>
<input id="btnClick" type="button" value="Submit Form"/>
</form>
<script type="text/javascript">
$(function () {
$("#btnClick").click(function()
{
$(".validateclass").each(function() {
var fieldValue =$(this).val();
if(fieldValue == null || fieldValue == "")
{
$(this).next().css( "color", "red" ).text("Field is required");
}
else
{
$(this).next().text("");
}
});
});
});
</script>

How to validate textbox or Browse button at a time?

I have question about how to validate input type=text or textbox OR input type="file" upload a file at a time using javascript or jquery?
1) If textbox is selected than no need to upload file.
2) If upload file is selected than no need to textbox.
3) Both

simple with required attribute
<form>
<input type="text" required="true">
<input type="file" required="true">
<button type="submit">validate</button>
</form>
Or with Javascript validation
Updated
$('button').click(function(){
var a =$(".validate").map(function(){
return $(this).val().trim() ? true : false
}).get()
if(a.includes(true)){
console.log('pass')
}
else{
console.log('select any one')
}
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" class="validate">
<input type="file" class="validate">
<button>validate</button>

" Just check both file and text box is empty or not before proceeding further."
if(!$('input:text').val().trim() && !$('input:file').val().trim()){
alert('Enter required data');
}

How to check if textbox is empty and display a popup message if it is using jquery?

I'm trying to check if the textbox is empty for my form. However, whenever I try to hit submit instead of an alert box message, telling me Firstname is empty I get "Please fill out filled".
('#submit').click(function() {
if ($('#firstname').val() == '') {
alert('Firstname is empty');
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form id="elem" autocomplete="on">
First Name:
<br>
<input type="text" name="firstname" id="firstname" required placeholder="Enter the first name" pattern="[A-Za-z\-]+" maxlength="25"><br>
<input type="submit" id="submit" value="Submit" />
</form>

Firstly I'm assuming that the missing $ is just a typo in the question, as you state that you see the validation message appear.
The reason you're seeing the 'Please fill out this field' notification is because you've used the required attribute on the field. If you want to validate the form manually then remove that attribute. You will also need to hook to the submit event of the form, not the click of the button and prevent the form submission if the validation fails, something like this:
$('#elem').submit(function(e) {
if ($('#firstname').val().trim() == '') {
e.preventDefault();
alert('Firstname is empty');
}
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form id="elem" autocomplete="on">
First Name:
<br>
<input type="text" name="firstname" id="firstname" placeholder="Enter the first name" pattern="[A-Za-z\-]+" maxlength="25"><br>
<input type="submit" id="submit" value="Submit" />
</form>
Personally I'd suggest you use the required attribute as it saves all of the above needless JS code - unless you need more complex logic than just checking all required fields have been given values.

Because you have the required property set.It is giving you Please fill out field validation as the error message.It is the validation that HTML5 is performing.

For this please make one function like :
function Checktext()
{
if ($('#firstname').val() == '') {
alert('Firstname is empty');
return false;
}
else
{
return true;
}
}
now call this function on submit button click like :
<input type="submit" id="submit" value="Submit" onclick="return check();" />

Disable button unless specific fields have values

I have an ASPX form and I need to disable the submit button if any one of six specific fields are empty. I'm trying to do this via Javascript or jQuery, but so far I can only find examples of either a single field on the form being empty, or ALL fields on the form. In my case, I don't care about several fields - only the six specific ones.
So basically, I have six conditions and one action. I found one example, but it was stringing together six different IF statements. I'd like to find a more streamlined way if possible. So, for example, I might do THIS for a single field... but how to do it for field2, field3, field4, etc. as well?
$(document).ready(function(){
$('#submit_btn').prop('disabled',true);
$('#field1').keyup(function(){
$('#submit_btn').prop('disabled');
})
});
Using Javascript or jQuery, what's the most efficient way to disable an input button if any of six input fields is blank?

You can add the same class name to all the elements and then do a validation foreach class element. Like in below code, i added the same class name to all the input for which the validation is required using class="valid" and then use the jquery class selector and the keyup method that you used to control the state of the button.
(function() {
$('.valid').keyup(function() {
var isEmpty = false;
$('.valid').each(function() {
if ($(this).val() == '') {
isEmpty = true;
}
});
if (isEmpty) {
$('#button1').attr('disabled', 'disabled');
} else {
$('#button1').removeAttr('disabled');
}
});
})()
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form>
1<input type="text" class="valid" /><br />
2<input type="text" class="valid" /><br />
3<input type="text" class="valid" /><br />
4<input type="text" class="valid" /><br />
5<input type="text" class="valid" /><br />
6<input type="text" class="valid" /><br />
<input type="button" id="button1" value="Test Me!" disabled="disabled" />
</form>

If your requirements will allow it, you can use HTML 5 field validation. The browser will not allow the form to submit.
<form>
<label for="choose">Foo</label>
<input name="bar" required>
<input type="submit" /> <!-- <--- This will generate an error message if the user clicks it when the field is empty -->
</form>

You have the start of it correct; create an array with six variables, one for each of the fields, and create a new function to validate everything that is called on each keyup. So you would have
var[] array
$('#field1').keyup(function() {
array[0] = $('#field1').val();
validate();
}
${'#field2').keyup(function() {
array[1] = $('#field2').val();
validate();
}
...create one each for each field
function validate() {
for (var i = 0; i < array.length; i++) {
if(!arrays[i]) {
$('#submit_btn').prop('disabled');
return;
}
}
$('#submit_btn').prop('enabled'):
}
What this does is it listens to the fields for changes and updates the array. A blank value is falsy so you can just go through the array and disable the button if it's blank or null or something. Break out of the for loop in that case; you don't care about whatever else. If nothing disables the button and breaks the for loop then it's valid and the button is enabled.
This approach is useful because it's easily extendable. You can just push extra things into the array if you want to check them without rewriting the validation function.
This assumes you do not want to just use standard form validation and do it manually.

Add a common class to each of the required inputs. Then check the length of that object against the length of a filtered object where value is not empty. Then you can use that condition to set the prop value of the button to true/false.
http://api.jquery.com/filter/
JQuery:
$('form .required-valid').on('input paste change', function() {
var $required = $('form .required-valid');
//filter required inputs to only ones that have a value.
var $valid = $required.filter(function() {
return this.value != '';
});
//set disabled prop to false if valid input count is != required input count
$('#submit_btn').prop('disabled', $valid.length != $required.length);
});
HTML:
<form>
<label>Field1</label>
<input type="text" id="field1" class="required-valid" />
<label>Field2</label>
<input type="text" id="field2" class="required-valid" />
<label>Field3</label>
<input type="text" id="field3" class="required-valid" />
<label>Field4</label>
<input type="text" id="field4" class="required-valid" />
<label>Field5</label>
<input type="text" id="field5" class="required-valid" />
<label>Field6</label>
<input type="text" id="field6" class="required-valid" />
<label>Field7</label>
<input type="text" id="field7" class="not-required" placeholder="not required" />
<button id="submit_btn" disabled>
Submit
</button>
</form>
Example:
https://jsfiddle.net/SeanWessell/q2msc80L/

$(document).ready(function() {
$('#submit_btn').prop('disabled', true);
$('#field1').keyup(function() { // on keyup
var value = $(this).val(); // retrieve the value of the input
if (value.length == 0) // if the value's length is 0 (empty)
$('#submit_btn').prop('disabled', true); // disable the button
else // if not
$('#submit_btn').prop('disabled', false); // enable it
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form>
<input id="field1"/>
<input id="submit_btn" type="submit"/>
</form>
Just note that the form can be submitted using enter key, so instead of checking on every keyup, it would be better if you check onsubmit instead.

HTML5 validation executes before custom validation

I have a form which asks user to give some input values. For some initial inputs i am doing custom validation using javascript. At the end of form one field is validated using "html required attribute". But when user clicks on submit button, input box which have required attribute shows message first instead of giving chance to previous ones i.e. not following order of error display. Below i added code and image , instead of showing that name is empty it directly jumps to location input box. This just confuses the end user. Why this problem occurs and how to resolve it?
<html>
<head>
<script>
function validate(){
var name = document.forms['something']['name'].value.replace(/ /g,"");
if(name.length<6){
document.getElementById('message').innerHTML="Enter correct name";
return false;
}
}
</script>
</head>
<body>
<form name="something" action="somewhere" method="post" onsubmit="return validate()">
<div id="message"></div>
Enter Name : <input type="text" name="name" /> <br/> <br/>
Enter Location : <input type="text" name="location" required="required" /> <br/> <br/><br/> <br/>
<input type="submit" name="submit" />
</form>
</body>
</html>

This is probably just the HTML5 form validation triggered because of the required attribute in the location input.
So one option is to also set the required attribute on the name. And or disable the HTML5 validation with a novalidate attribute. See here for more information: https://stackoverflow.com/a/3094185/2008111
Update
So the simpler way is to add the required attribute also on the name. Just in case someone submits the form before he/she entered anything. Cause HTML5 validation will be triggered before anything else. The other way around this is to remove the required attribute everywhere. So something like this. Now the javascript validation will be triggered as soon as the name input looses focus say onblur.
var nameElement = document.forms['something']['name'];
nameElement.onblur = function(){
var messageElement = document.getElementById('message');
var string = nameElement.value.replace(/ /g,"");
if(string.length<6){
messageElement.innerHTML="Enter correct name";
} else {
messageElement.innerHTML="";
}
};
<form name="something" action="somewhere" method="post">
<div id="message"></div>
Enter Name : <input type="text" name="name" required="required" /> <br/> <br/>
Enter Location : <input type="text" name="location" required="required" /> <br/> <br/><br/> <br/>
<input type="submit" name="submit" />
</form>
Now the above works fine I guess. But imagine you might need that function on multiple places which is kind of the same except of the element to observe and the error message. Of course there can be more like where to display the message etc. This is just to give you an idea how you could set up for more scenarios using the same function:
var nameElement = document.forms['something']['name'];
nameElement.onblur = function(){
validate(nameElement, "Enter correct name");
};
function validate(element, errorMessage) {
var messageElement = document.getElementById('message');
var string = element.value.replace(/ /g,"");
if(string.length < 6){
messageElement.innerHTML= errorMessage;
} else {
messageElement.innerHTML="";
}
}
<form name="something" action="somewhere" method="post">
<div id="message"></div>
Enter Name : <input type="text" name="name" required="required" /> <br/> <br/>
Enter Location : <input type="text" name="location" required="required" /> <br/> <br/><br/> <br/>
<input type="submit" name="submit" />
</form>