unable to validate JS form using for..of loop - javascript

I have a form with empty field validation. But when i'm trying to submit the form with some input fields filled, it is executing both conditions given under if and else statement.
JS
let inputTags = document.querySelectorAll( 'input' )
for ( let input of inputTags )
{
if ( input.value === "" && !input.classList.contains( 'hidden' ) )
{
promptMessages( 'All fields are required.' )
input.focus()
break;
}
else
{
console.log( input.value )
}
}
How do I ensure that else condition is executed only when all fields are filled and not when some are.
OR
Is there a better way to validate the form by using just JS?

At the moment you are checking each input separately and go to the else clause, if the if clause isn't fulfilled. If you want to only execute the else clause, when all fields are filled, then you could for example use a flag outside the for-loop.
const inputTags = document.querySelectorAll('input');
let allFilled = true;
for (const input of inputTags){
if (input.value === "" && !input.classList.contains('hidden')){
promptMessages('All fields are required.');
input.focus();
// Set the flag to false, since at least one input isn't filled
allFilled = false;
break;
}
}
// Check if flag is true
if (allFilled) {
// Execute the code, which was previously in the else clause
console.log( input.value )
}
There are other ways to do it, but this is one example.

Related

Loop through all input item which aren't a filetype

I have the following code which is being used as validation on input fields. However, I'm getting stuck as it's checking input filetype fields as well, which I don't want it to do. Is there a way of getting it to ignore an file input field?
function validateForm() {
// This function deals with validation of the form fields
var x, y, i, valid = true;
x = document.getElementsByClassName("tab");
y = x[currentTab].getElementsByTagName("input");
// A loop that checks every input field in the current tab:
for (i = 0; i < y.length; i++) {
//I only want the following condition statement to run if the current element is not a file field.
// If a field is empty...
if (y[i].value == "") {
// add an "invalid" class to the field:
y[i].className += " invalid";
// and set the current valid status to false
valid = false;
}
}
// If the valid status is true, mark the step as finished and valid:
if (valid) {
document.getElementsByClassName("step")[currentTab].className += " finish";
}
return valid; // return the valid status
}
One option is to use querySelectorAll instead, and use :not([type="file"]):
y = x[currentTab].querySelectorAll('input:not([type="file"])');
You can also consider making the fields required to help improve UI, in addition to the Javascript.
To refactor a bit, consider using more meaningful variable names, and using classList.add so as to avoid adding duplicate class attributes to elements:
function validateForm() {
const thisTab = document.getElementsByClassName("tab")[currentTab];
const inputs = thisTab.querySelectorAll('input:not([type="file"])');
let valid = true;
for (const input of inputs) {
if (input.value === '') {
input.classList.add('invalid');
valid = false;
}
}
// If the valid status is true, mark the step as finished and valid:
if (valid) {
thisTab.classList.add('finish');
}
return valid; // return the valid status
}

get all required inputs and check them on page load

function showloading()
{
$('input[required="required"]').each(function(){
if( $(this).val() == "" ){
alert('Please fill all the fields');
return false;
}
});
window.scrollTo(0,0);
var x = Math.floor((Math.random() * 10) + 1);
$("#loading-"+x).show(1000);
}
i have the above function
now everything working fine except that the line
return false;
didn't work just the alert working but its Continuing the code
what i want is to check if the page has required field
it the required field is empty
dont run this code
window.scrollTo(0,0);
var x = Math.floor((Math.random() * 10) + 1);
$("#loading-"+x).show(1000);
thanks
Here is an implementation in pure javascript
function showloading() {
// get a NodeList of all required inputs, and destructure it into an array
const required = [...document.querySelectorAll('input[required]')];
// Use Array.prototype.some() to find if any of those inputs is emtpy
// and if so, return false (exiting showLoading)
if (required.some(input => input.value === '')) {
alert('Please fill all the fields');
return false;
}
/* whatever you want to do if all required fields are non-empty */
}

Conditional javascript input field validation

I am currently working on a project that requires me to do a javascript form validation on a form that contains conditional input fields ( the visitor can choose whether to log in via a user number or email address ). Both input fields are separate and I need to do the following:
If visitor chooses to log in via option A ( user number ), the validation should only take into account the id of input field A ( the user number ) and not require validation for the other field ( email address ).
And vice versa, if visitor chooses option B.
The code I am currently using for validation:
function empty() {
var x;
x = document.getElementById("user_number").value;
if (x == "") {
MsgBox('Your user number is required.', 'ERROR');
return false;
}
var y;
y = document.getElementById("email").value;
if (y == "") {
MsgBox('Your email address is required.', 'ERROR');
return false;
}
}
And the form trigger event:
<form method="POST" id="accordion-top-form" action="" onsubmit="return empty();">
I need to expand the current script to check if either field A or field B has been filled in when submitting the form ( and then automatically disable validation for the other field ).
How do I do that?
You could use the following:
var forms = {
user: 0,
email: 1
};
function whichForm() {
var userForm = document.getElementById("user_number").value;
var emailForm = document.getElementById("email").value;
if (userForm && emailForm) {
//user wrote in both forms, something is wrong
} else if (!userForm && !emailForm) {
//user didn't fill in any form
} else {
return userForm ? forms.user : forms.email;
}
}
function empty(form) {
if (form === forms.user) {
// check if the user number form is empty
var userForm = document.getElementById("user_number").value;
if(userForm.trim() === "") {
// possibly do more validation
// return true or false based on whether you want to submit
}
} else if (form === forms.email) {
// check if the email form is empty
var emailForm = document.getElementById("email").value;
if(emailForm.trim() === "") {
// possibly do more validation
// return true or false based on whether you want to submit
}
} else {
// something is wrong, invalid parameter,
// handle here
return false
}
}
function validate() {
return empty(whichForm());
}
And change your form so that it calls return validate() inline or just validate as a submit handler.
Sounds like this would be enough?
I would personally not call the function empty since you want to return true to allow submission
function empty() {
var x = document.getElementById("user_number").value,
y = document.getElementById("email").value;
x = x?x.trim()|| ""; // handle null and all blanks
y = y?y.trim()|| "";
if (x === "" && y === "") {
alert("Please enter user number or email")
return false;
}
// optional
if (x && y) { // both entered
alert("Please enter EITHER user number or email")
return false;
}
if (x) return isValidUser(x); // each of these functions needs to return boolean
if (y) return isValidEmail(y);
// likely not going to happen
return false;
}
You can test if both are empty
function empty() {
var a = document.getElementById("user_number").value,
b = document.getElementById("email").value;
if ("" == a && "" == b) return MsgBox("Your user number or mibile is required.", "ERROR"), !1
};
Code do it in this way:
function empty() {
var x = document.getElementById("user_number").value,
y = document.getElementById("email").value;
if (!x && !y) {
alert('You should choose email address or number');
return false;
}
return true;
}
Proposed solution:
Check which of the two input fields is filled up:
var inputA = document.getElementById('A').value;
var inputB = document.getElementById('B').value;
if ((inputA !== "") || (inputA !== NaN) || (inputA !== undefined)) {
//execute code for the user number
}
else if ((inputB !== "") || (inputB !== NaN) || (inputB !== undefined)) {
//execute code for the email
}
else {
//display an error saying none of the two fields were used
}
Recommendation: Most websites would only use 1 input because it looks a lot cleaner. And the place holder text can specify to the user what input options he should put in:
<input type="text" id="input1" placeholder="user number or email">
Proposed Solution: Check if the user input has a # symbole:
var input1 = document.getElementById("input1").value;
var emailInput = input1.includes('#');//returns a boolean with a value of true
//if '#' was found in the string input1
if (emailInput) {
//execute the code for the email input
} else {
//execute the code for the userID input
}
Explanation:
I assumed that you wanted to use the same input field inside your <form ...> tag regardless if the user is using an email or an id number to log in. From that, what I saw as most logical is to just find something that is unique to one of those inputs, and base the logic of your code on whether that unique element existed in the input provided.
AKA since emails always have the # symbol, verifying if this exists in the provided string or not should be enough to verify if the user used an email or id number to attempt to login.
Let me know if that helped :).

How to use JavaScript to Require a Ratio of Completed Fields in a Form

I'm looking for a way to use JavaScript to require a specific ratio of fields in a form to be complete. So if I have six fields and the user has to complete any 2/6 to submit. If not then they receive an error. (The form will actually have a few different groups like this in it, so I have to be able to identify specific fields for the ratio.)
After some more research I've found something close, and realize I can count the number of a class. How would I change this to say if number of checked boxes is greater than or equal to 2, return true?
document.getElementById("test").onclick = function() {
isCountCheck("Check something");
};
function isCountCheck(helperMsg) {
var i, len, inputs = document.form1.getElementsByClassName("checkbox");
for (i = 0, len = inputs.length; i < len; i++) {
if (inputs[i].type === "checkbox" && inputs[i].checked) return true;
}
alert(helperMsg);
return false;
}
UPDATE:
My final jQuery ended up like this.
function isCountCheck(){
if($("input[class=crit1]:checked").length >= 4)
return false;
alert("Check a box");
return true;
}
Using jQuery
var numberOfInputsCompleted = 0;
var allInputs = $(":input"); // returns all input fields on the document
var numberOfInputs = allInputs.length
allInputs.each(function () {
if($(this).val() != '') {
numberOfInputsCompleted = numberOfInputsCompleted + 1;
}
});
numberOfInputsCompleted would give fields completed and numberOfInputs would total number of input fields on the form. Hope this helps
The first thing that comes to my mind: create a function that counts filled fields and returns true if the number of filled fields is enough (false otherwise). Then add it to the form as an "onsubmit" function. When the submit button is clicked the function is executed and, depending on what the function returns (true or false), the form is submitted or not.
More info about javascript form validation: http://www.w3schools.com/js/js_form_validation.asp

Including a for loop in an if statement

I'm building an application in which I want to display some errors when a user enters invalid values in an input box. A correct value is appended as 'entry' to a div if no errors were found. In total there are 3 cases when to display errors:
The input value is empty
The input value is a number
The input value already exists
These errors are displayed with if else statements.
1.and 2. were easy, but the problem case (3.) only validates against the first element of class .cat_entry.
if(cat_input == '') { // generate errors
errorDisplay(error_input_empty);
} else if(!isNaN(cat_input)) {
errorDisplay(error_input_number);
} else if($('.cat_entry') == cat_input) { // THIS IS THE PROBLEMATIC LINE
// .cat_entry is the class of the entries that have been appended
errorDisplay(error_duplicate);
} else {
// stuff
};
So I believe I need a for loop/ .each() (no problem so far), but how do I include this as a condition in an if statement? Something like.. if( for(i=0;i<$('.cat_entry').length;i++) { ... }; ... How to return true (or something similar) when one of the entries matches the input value, then pass the return value to the if statement?
EDIT: here is a jsFiddle with the relevant code. I updated it with $.inArray() method. I'd like to try and use this instead of a for / .each() loop.
You can try this:
var a=$('.cat_entry'),o={};
for(i=0;i<a.length;i++) {
var s=a[i].val();
if(s in o){
errorDisplay(error_duplicate);
return;
}
o[s]=true;
}
or
var o={};
$('.cat_entry').each(function(){
var s=$(this).val();
if(s in o){
errorDisplay(error_duplicate);
return;
}
o[s]=true;
}
You can actually use the jQuery inArray function for this, such as:
else if($.inArray(cat_input, $('.cat_entry') != -1)
}
The solution was to add this to the function:
var isDuplicate = false;
$('.cat_entry').each(function() {
if(!$(this).text().indexOf(cat_input)) {
isDuplicate = true;
}
// And in the if else loop:
else if(isDuplicate == true)
//and just before the function ends
isDuplicate = false;
Thanks to all for the help you offered.

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