Form Validation - How to use If and Else If - javascript

I am trying to do a Javascript form validation, and I want to set the formValue to 0 in several cases. That is, if ANY of the required fields are not filled out, the value should go to 0.
function formValidation() {
var formValue = 1;
if (document.getElementById('orgname').value == '') formValue = 0;
else if (document.getElementById('culture[]').value == '') formValue = 0;
else if (document.getElementById('category[]').value == '') formValue = 0;
else if (document.getElementById('service[]').value == '') formValue = 0;
if (formOkay == 1) {
return true;
} else if (formOkay == 0) {
alert('Please fill out all required fields');
return false;
}
}
Is there a more elegant way to do this?
EDIT: Script does not appear to be working, now.

You can do some looping:
var toCheck = ['orgname', 'culture[]', 'category[]', 'category[]']
for(var id in toCheck )
{
if(document.getElementById(id).value == ''){
formValue = 0;
break;
}
}
A more elegant way can be that you specify a 'required' class on each input that you want to check and than do the following using jQuery:
$(document).ready(function(){
var toCheck = $('.required');
var formValue = 1;
$.each(toCheck, function(index, element){
if(element.val() == '')
formValue = 0;
});
});

I've done this in other languages using boolean logic, taking advantage of the & operator. It always returns false if any of the values are false.
Something like:
function formValidation() {
var formValue = true;
formValue &= document.getElementById('orgname').value != '';
formValue &= document.getElementById('culture[]').value != '';
formValue &= document.getElementById('category[]').value != '';
formValue &= document.getElementById('service[]').value != '';
if(!formValue) {
alert('Please fill out all required fields');
}
return formValue;
}
This has the advantage of working for other scenarios where your logic is more complicated. Anything that evaluates in the end to true/false will fit right in with this solution.
Then I'd work on reducing logic duplication:
function formValidation() {
var formValue = true;
var elementIdsToCheck = ['orgname', 'culture[]', 'category[]', 'category[]'];
for(var elementId in elementIdsToCheck) {
formValue &= document.getElementById(elementId).value != '';
}
if(!formValue) {
alert('Please fill out all required fields');
}
return formValue;
}

Something like this should help (this assumes that value attribute is available on the referenced elements):
var ids = ["orgname", "culture[]", "category[]", "service[]"],
formValue = 1; // default to validation passing
for (var i = 0, len = ids.length; i < len; i++) {
if (document.getElementById(ids[i]).value === "") {
formValue = 0;
break; // At least one value is not specified so we don't need to continue loop
}
}

Building upon #Baszz's second answer using jQuery, you could also build a more generic solution using HTML5 data- attributes:
$(function() {
$('form').submit(function() {
var toValidate = $(this).find('input[data-validation]');
for(var i=0; i<toValidate.length; i++) {
var field = $(toValidate[i]);
if(field.val().search(new RegExp(field.data('validation'))) < 0) {
alert("Please fill out all required fields!");
return false;
}
}
});
});
You can then specify regular expressions in your markup:
<form>
<input type="text" data-validation=".+" />
</form>
For required fields you can use ".+" as a regular expression, meaning the user has to enter at least one character, but you can of course use the full potential of regular expressions to check for valid email addresses, phone numbers or zip codes etc...

Related

How to check javascript nodelist if it's contents are either all empty or all have values?

I'm fairly new to javascript and looking at checking some fields with dynamic ID's at the end of the ID to see if they've either had values entered in all of them or none of them at all. The user shouldn't be allowed to only enter values in some of them and leave others blank.
I've wrote the below, which works, but I feel there must be a better way of doing this?:
var x = document.querySelectorAll('[id^="entryField"]');
for (var i = 0; i < x.length; ++i) {
if (x[i].value == "") {
for (var i = 0; i < x.length; ++i) {
if (x[i].value != "") {
alert("Please enter a value");
}
}
}
}
One loop should work with a counter for empty (or filled) fields. If the counter is not zero and does not have the length of the object, then some fields have a value.
var x = document.querySelectorAll('[id^="entryField"]'),
empty = 0;
for (var i = 0; i < x.length; ++i) {
if (x[i].value == "") {
++empty;
}
}
if (empty !== 0 && empty !== x.length) {
alert("Please enter a value");
}
This will be a simpler version:
var x = document.querySelectorAll('[id^="entryField"]');
const inputs = Array.from(x);
const allInput = inputs.every(input => {
return (input.value != "");
});
const allEmpty = inputs.every(input => {
return (input.value == "");
});
if (allInput || allEmpty) {
alert('xxxxxx');
}
ES5 implementation:
var x = document.querySelectorAll('[id^="entryField"]');
var inputs = Array.from(x);
var allInput = inputs.every(function(input) {
return (input.value != "");
});
var allEmpty = inputs.every(function(input) {
return (input.value == "");
});
if (allInput || allEmpty) {
alert('xxxxxx');
}
EDIT: Support allInput or allEmpty. Overlooked at the beginning.
You can check with two every calls, below will be true if all elements are filled or none of the elements are filled - every other case will be false:
var x = document.querySelectorAll('[id^="entryField"]');
var allowed = function allOrNone(elements) {
return Array.prototype.every.call(x, function(v) {
return v.value && v.value != "";
}) || Array.prototype.every.call(x, function(v) {
return !v.value || v.value == "";
});
}
console.log(allowed(x));
<input id="entryFieldFoo">
<input id="entryFieldBar">

JavaScript validation using inputs as array

Hi I am trying to validate my inputs using JavaScript, I have the inputs in an array and I am trying to use them to extract information like .value and set values such as .className. This is not working as I would like it to. What I want the code to do is if I define input[1] = document.forms["register"]["username"]; then use input[1].value it interprets this as if I have written document.forms["register"]["username"].value
Here is my original code:
function validateForm() {
var inputs = [];
inputs[0] = document.forms["register"]["firstname"];
inputs[1] = document.forms["register"]["lastname"];
inputs[2] = document.forms["register"]["username"];
inputs[3] = document.forms["register"]["email"];
inputs[4] = document.forms["register"]["password"];
inputs[5] = document.forms["register"]["confirmpassword"];
for (i = 0; i < inputs.length; i++) {
if (inputs[i].value == null || inputs[i].value == "") {
alert("Highlighted fields must be filled out");
inputs[i].className += " invalid";
return false;
}
}
return true;
}
Here is my updated code, I am unsure of whether this is good practice:
function validateForm() {
var error = false;
var inputs = [];
inputs[0] = document.forms["register"]["firstname"];
inputs[1] = document.forms["register"]["lastname"];
inputs[2] = document.forms["register"]["username"];
inputs[3] = document.forms["register"]["email"];
inputs[4] = document.forms["register"]["password"];
inputs[5] = document.forms["register"]["confirmpassword"];
console.log(inputs.length);
for (i = 0; i < (inputs.length); i++) {
if (inputs[i].value == null || inputs[i].value == "") {
error = true;
inputs[i].className += " invalid";
if (inputs[i] == (inputs.length - 1)) {
alert("Highlighted fields must be filled out");
return false;
}
}
}
if (error == false) {
return true;
}
alert("Highlighted fields must be filled out");
return false;
}
The class invalid adds a red border to the field.
Thanks.
i changed your function a bit to read input elements as in the plnkr link below
https://plnkr.co/edit/zHhM6lmz3XA2u4CYr9h0?p=preview
function validate() {
var inputs = [];
var elements = document.forms["register"].elements;
for (var i = 0; i < elements.length; i++) {
var element = elements[i];
if (element.type === "text" || element.type === "email" || element.type === "password") {
inputs.push(element)
}
}
for (i = 0; i < inputs.length; i++) {
if (inputs[i].value == null || inputs[i].value == "") {
alert("Highlighted fields must be filled out");
inputs[i].className += " invalid";
return false;
}
}
return true;
}
I have handled three input types
text
email
password
You can add more later if needed
Edit: Possible cause of error can be DOM element not available inside the form (please share HTML if possible). First loop will read all available DOM element from the form.
function validateForm() {
var inputs = [];
inputs[0] = document.forms["register"]["firstname"];
inputs[1] = document.forms["register"]["lastname"];
inputs[2] = document.forms["register"]["username"];
inputs[3] = document.forms["register"]["email"];
inputs[4] = document.forms["register"]["password"];
inputs[5] = document.forms["register"]["confirmpassword"];
for (i = 0; i < inputs.length; i++) {
if (inputs[i].value == null || inputs[i].value == "") {
alert("Highlighted fields must be filled out");
inputs[i].className += " invalid";
return false;
}
}
return true;
}

Validating Radio entry

I have 2 address entries on my form. I also have 2 radio buttons to designate the "preferred" mailing address.
I'm attempting to validate these 2 and am not really sure if I'm doing it correctly. It seems to work if I have both addresses filled but I can't seem to get it to validate correctly if one of the addresses isn't filled.
Here's the javascript that does the validation:
function checkMailingPrefs() {
var prefs = ["MailPrefHome", "MailPrefBusi"];
var field = ["HomeAddress1", "BusinessAddress1"];
for (i = 0; i < 2; i++) {
if ($("#"+prefs[i]).is(":checked") && $("#"+field[i]).val() == "") {
$("#" + prefs[i]).prop('checked', false);
$("#MailPrefBusi").validationEngine('showPrompt', 'You must select the correct Mailing Preference', 'error', true);
return false;
}
if ($("#"+field[i]).val() == "" || !$("#"+prefs[i]).is(":checked")) {
$("#MailPrefBusi").validationEngine({promptPosition : "bottomRight", scroll: true}).validationEngine('showPrompt', 'You must select the correct Mailing Preference', 'error', true);
return false;
}
}
return true;
}
I'm using jQueryValidationEngine but it also doesn't correctly validate them. I only use it to show the validation error for these fields.
Here is the criteria:
If the MailPrefBusi is checked, then the BusinessAddress1 must be filled in.
If the MailPrefHome is checked, then the HomeAddress1 must be filled in.
If no MailPrefxxx is checked, show error. If no xxxAddress1 is filled, Show error.
It looks like your second if statement if ($("#"+field[i]).val() == "" || !$("#"+prefs[i]).is(":checked")) { is returning false when you don't want it to. You should be able to accomplish what you want using this:
function checkMailingPrefs() {
var prefs = ["MailPrefHome", "MailPrefBusi"];
var field = ["HomeAddress1", "BusinessAddress1"];
for (i = 0; i < 2; i++) {
if ($("#"+prefs[i]).is(":checked") && $("#"+field[i]).val() == "") {
// enhanced validation function call here
return false;
}
}
//if the user hasnt checked anything, you can remove this if the form should validate without the user having to set a radio button
if(!$("#MailPrefBusi, #MailPrefHome").is(":checked")) {
// enhanced validation function call here
return false
}
return true;
}
You can see it working at this JS Fiddle: https://jsfiddle.net/h0vj9r35/
Hope that helps!
If you are trying to figure out whether the corresponding fields are filled based on checkbox values in a scenario where you have n no. of checkboxes and fields and would like to avoid hardcoding of values, you may use the following:
var prefs = ["MailPrefHome", "MailPrefBusi"];
var field = ["HomeAddress1", "BusinessAddress1"];
var allEmpty = false;
var valueError = ""
for (i = 0; i < 2; i++)
{
if ($("#"+field[i]).val() == "" || !$("#"+prefs[i]).is(":checked")) {
if(!$("#"+prefs[i]).is(":checked"))
valueError += prefs[i] + "," ;
else if($("#"+field[i]).val() == "")
valueError += field[i];
allEmpty = true;
}
if ($("#"+prefs[i]).is(":checked") && $("#"+field[i]).val() == "")
{
$("#" + prefs[i]).prop('checked', false);
allEmpty = false;
alert("Need to enter " + field[i]);
return false;
}
if((i == 1) && allEmpty)
{
alert("You need to select " + valueError);
return false;
}
}
return true;
http://jsfiddle.net/n0303qd6/1/

Check if input fields are filled out in a form

I have a form myForm and I want to check if specific input field are filled out before sending the form. I'm very new to JavaScript so I don't really know what I did wrong. Any help is welcomed.
function validateForm() {
var validate = true;
var alert_string = "";
var children = $("#myForm").children("input");
console.log(children.size());
for(var i = 0; i < children.length ; i++){
if(children[i].attr(id).substring(0,8) != "ABC_FLAT"){
if(children[i].attr(id) == null || children[i].attr(id) == ""){
validate = false;
alert_string = alert_string.concat(childrern[i].attr(id)).concat(", ");
}
}
}
alert_string = alert_string.concat("must be filled out !");
if(validate == false){
alert(alert_string);
return false;
}
return true;
}
children[i].attr(id) == "" // wrong
You don't have to check whether their ids are null, you have to check whether their values are empty :)
if(children[i].value == "")
Since you are already using jQuery, you can simplify that code to a great extent. For example a simple "all fields filled" check can be
var flag=0;
$('#myForm').each(function() {
if ( $(this).val() === '' )
flag=1;
});
if you'll use jQuery, you can check the input fields if empty AND trap also white space/s. Add a class to all input fields , e.g. class="required" and add attribute fieldname with respective value for each input field.
var requiredFields = "";
$("#myForm").find('.required').each(function () {
if ($(this).val().trim().length == 0) {
requiredFields += " - " + $(this).attr("fieldname") + "\n";
}
});
if (requiredFields != "") {
alert("Please enter the following required field(s): \n" + requiredFields);
} else {
//save here
}
You can use required like <input required type="text" name="email" id="log" /> or use jQuery like
$("form").submit(function() {
var has_empty = false;
$(this).find('input').each(function() {
if(! $(this).val()) {
has_empty = true;
return false;
}
});
if(has_empty){return false;}
});

Submit form only if all required fields are full?

I want to do form.submit() but only if all form items with the required attribute are full.
I was thinking on simpy iterating through the form children in search for the attribute, but I'm not sure how to do it since there might be nested elements and such. And probably there is an easier way to do it.
this.form_is_full = function(form){
for (var i = 0; i < form.elements.length; i++){
if(form.elements[i].getAttribute("required") && form.elements[i].value=="")
{
// If has attribute required and is blank return false
}
}
return true;
}
How can I do this?
function Validate()
{
// create array containing textbox elements
//for example:
var inputs = [document.getElementById('fname'),
document.getElementById('lname'), document.getElementById('email'),
document.getElementById('messagetxt')];
var error;
for(var i = 0; i<inputs.length; i++)
// loop through each element to see if value is empty
{
if(inputs[i].value == '')
{
error = 'Please complete all fields.';
alert(error);
return false;
}
}
}
Try this:
$('#YourFormId').submit(function(e) {
if ($.trim($("#YourFormId input").val()) === "") {
e.preventDefault();
alert('you did not fill out one of the fields');
}
});
This is what I did:
this.validate_form = function(form){
for (var i = 0; i < form.elements.length; i++){
if(form.elements[i].value == "" && form.elements[i].getAttribute("name") && form.elements[i].hasAttribute("required"))
{
return false;
}
}
return true;
}

Categories