jQuery: Problems with detecting if a checkbox is checked - javascript

I'm creating a small jQuery plugin for my CMS that styles certain form input types (just radio, checkbox at the moment). It works by hiding the original form element and placing a normal HTML element (for styling with CSS) in the input's place. It then detects actions on the element and updates the original input accordingly. Additionally, it will also work when the associated label is clicked. Here is my code:
jQuery.fn.ioForm = function() {
return this.each(function(){
//For each input element within the selector.
$('input', this).each(function() {
var type = $(this).attr('type');
//BOF: Radios and checkboxes.
if (type == 'radio' || type == 'checkbox') {
var id = $(this).attr('id');
checked = '';
if ($(this).attr('checked')) {
checked = 'checked';
}
//Add the pretty element and hide the original.
$(this).before('<span id="pretty_'+ id +'" class="'+ type +' '+ checked +'"></span>');
$(this).css({ display: 'none' });
//Click event for the pretty input and associated label.
$('#pretty_'+ id +', label[for='+ id +']').click(function() {
if (type == 'radio') {
//Radio must uncheck all related radio inputs.
$(this).siblings('span.radio.checked').removeClass('checked');
$(this).siblings('input:radio:checked').removeAttr('checked');
//And then check itself.
$('#pretty_'+ id).addClass('checked');
$('#'+ id).attr('checked', 'checked');
} else if (type == 'checkbox') {
if ($('#'+ id).attr('checked')) {
//Checkbox must uncheck itself if it is checked.
$('#pretty_'+ id).removeClass('checked');
$('#'+ id).removeAttr('checked');
} else {
//Checkbox must check itself if it is unchecked.
$('#pretty_'+ id).addClass('checked');
$('#'+ id).attr('checked', 'checked');
}
}
});
} //EOF: Radios and checkboxes.
});
});
};
This works great for the radio, but the checkbox seems to get stuck when clicking the checkbox label for a second time - the first click of the label successfully changes it to the appropriate state, but clicking the label again doesn't change it (however the checkbox itself still works fine). It works perfectly in IE8.
I've checked the id is correct and it is. I've also tried a few other methods I stumbled across of checking if the checkbox is checked, but they either gave the same result or failed altogether. :(
Any help would be much appreciated.
Thanks :)
Update
Here is the HTML, which is generated by a PHP class. This is after the jQuery has run and added in the span elements:
<div>
<p class="label">Test:</p>
<span id="pretty_test_published_field" class="checkbox"></span>
<input class="checkbox" id="test_published_field" name="test" type="checkbox" value="published">
<label for="test_published_field" class="radio">Published</label>
<span id="pretty_test_draft_field" class="checkbox"></span>
<input checked="checked" class="checkbox" id="test_draft_field" name="test" type="checkbox" value="draft">
<label for="test_draft_field" class="radio">Draft</label>
</div>

Just use the infallible and extremely simple DOM checked property. jQuery is inappropriate for this and apparently makes one of the simplest JavaScript tasks there is error-prone and confusing. This also goes for the id and type properties.
$('input', this).each(function() {
var type = this.type;
if (type == 'radio' || type == 'checkbox') {
var id = this.id;
var checked = this.checked ? 'checked' : '';
// Etc.
}
});
UPDATE
The default action of clicking a <label> element associated with a checkbox is to toggle the checkbox's checkedness. I haven't tried this myself with labels for hidden form elements, but perhaps the toggling is still happening because you're not preventing the browser's default click action. Try the following:
//Click event for the pretty input and associated label.
$('#pretty_'+ id +', label[for='+ id +']').click(function(evt) {
if (type == 'radio') {
//Radio must uncheck all related radio inputs.
$(this).siblings('span.radio.checked').removeClass('checked');
$(this).siblings('input:radio:checked').each(function() {
this.checked = false;
});
//And then check itself.
$('#pretty_'+ id).addClass('checked');
$('#'+ id)[0].checked = true;
evt.preventDefault();
} else if (type == 'checkbox') {
if ($('#'+ id).attr('checked')) {
//Checkbox must uncheck itself if it is checked.
$('#pretty_'+ id).removeClass('checked');
$('#'+ id)[0].checked = false;
} else {
//Checkbox must check itself if it is unchecked.
$('#pretty_'+ id).addClass('checked');
$('#'+ id)[0].checked = true;
}
evt.preventDefault();
}
});

i've found on the odd accassion that i need to use the alternative of:
$("#checkboxID").is(':checked');
this may or not be an alternative in your scenario, but worth noting. Also, you may have to add the 'live' event, rather than 'click' if changes to the dom are occurring. i.e.
.click(function()
to
.live('click', function()
jim

The checked attribute of a checkbox is mapped to the defaultChecked property and not to the checked property. Use the prop() method instead.
If elem is the checkbox, use:
elem.checked
or
$(elem).prop("checked")
This gives us the proper state information of the checkbox and changes as the state changes.
This seems to be the reason of confusion in many cases. So its good to keep in mind the underlying reason behind this.

Could you show us the HTML? I am looking to see if you set a value property for the checkbox in the HTML. There is a possibility that broke it.
<input type="checkbox" value="This May Break Checkbox" />
<input type="checkbox" name="This Checkbox Works" />

Related

Express handlebars, can't bind checked attribute to checkbox

I am opening some divs when a user clicks on a certain checkbox like so:
$(document).ready(function () {
$('input[type="checkbox"]').click(function () {
var inputValue = $(this).attr("value");
if ($(this).prop("checked") == true) {
$("." + inputValue).show();
}
else if ($(this).prop("checked") == false) {
$("." + inputValue).hide();
}
});
});
Then, I store the classes of the checked boxes and if the user gave me bad input I redirect them to the submission page, I store the checked boxes like so:
allEvents={'coinChecked':true,'crinChecked':true,'ppChecked':false,'quizChecked':false}
Now I pass this allEvents object back to the submission page with res.render(check:allEvents)
Then, I use the following code (on SO) to bind the checked attribute to a checkbox, and hence open the initially hidden div with :
<input type="checkbox" name="events" value="coin" {{bindAttr checked="check.coinChecked"}}> Code-in
But neither does this make the checkbox "checked", nor does it display the hidden div.
How can I do this, or is there a workaround for this process?
thanks
<input type="checkbox" name="events" value="coin" checked={{if(check.coinchecked){{checked}}}}> Code-in
might do the trick

Jquery - Ensure all checkboxes are selected

I am trying to create a JS function that will ensure all checkboxes in my form are selected.
I have tried the following, but it isn't working. There are other checkboxes in another from on this page so I am wondering if this is conflicting? I thought using $(this) would fix that issue...
$('#my-form').on('submit', function(e) {
e.preventDefault();
var checked = false;
$('#input[type="checkbox"]').each(function() {
if ($(this).is(":checked")) {
checked = true;
}
});
if (checked == false) {
console.log('Something wasnt checked');
}
});
Can any advise what I am doing wrong here please?
Your code checks if any of the checkboxes are checked.
Change the code to
var checked = true;
And set the variable to false, if the checkbox in the loop is NOT checked.
"#" is used to query elements by their ID, so $("#input") would target only one input that has id="input". You should instead do this:
$("input[type='checkbox']")
or, if you don't want all checkboxes on the page you will need to use some other selector, etc. add class "some-class" to all inputs that you want to check and use:
$(".some-class")
Also, you will need to revert your logic, cause currently you will set checked to true if any of the checkboxes is checked. So, initially use checked = true, then in if statement set it to false if it's not checked.
Just check :checked checkbox length based upon that set your variable like below.
$('input[type="checkbox"]').click(function() {
var checked = false;
if ($('input[type="checkbox"]:checked').length == $('input[type="checkbox"]').length)
checked = true;
if (checked == true)
console.log('checked');
else
console.log('false');
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input checked="checked" type="checkbox">
<input checked="checked" type="checkbox">

.toggle() issue with jquery

I have a form wherein there is a question where you can select multiple answer including Others by ticking the checkboxes. Then you tick others, it's suppose to show a textbox and when unticked, it should hide the textbox again.
What happens is when I untick it, yes it hides but the validation error still pops up. I'm not sure what's causing it. In other words, despite the fact that it is hidden, it is still validating.
Here's my javascript:
$("input[name = 'production-up']").change(function () {
//check if the selected option is others
if (this.value === "other") {
//toggle textbox visibility
$("#productionUpOther").toggle();
}
});
and my HTML:
<span id='productionUp' class='level'>
<p>Production - Reasons why it is up. Click as many as apply.</p>
<input type='checkbox' name='production-up' value='Increase in demand' required>Increase in demand <br/>
<input type='checkbox' name='production-up' value='Expected increase in demand'>Expected increase in demand <br/>
<input type='checkbox' name='production-up' value='Fullfillment of past orders'>Fulfillment of past orders <br/>
<input type='checkbox' name='production-up' value='Increased marketing activity'>Increased marketing activity <br/>
<input id="other" type="checkbox" name="production-up" value='other' />Other
<input id='productionUpOther' name='other-production-up' type='text' required/>
</span>
Be informed that this is just a part of my code. Any ideas on how to do something about this?!
Here you can that I ticked other
But when I untick it and press Next it still needs to be validated.
You can try this:
$("input[name = 'production-up']").change(function () {
//check if the selected option is others
if (this.value === "other") {
//toggle textbox visibility
$("#productionUpOther").toggle();
if (this.checked) {
$("#productionUpOther").attr('required','1');
} else {
$("#productionUpOther").removeAttr('required');
}
}
});
What you wanna do is disabling the text field 'other'. So in this case, I would use the 'disabled' property and then hide the field using CSS.
An example could be :
JS
$("#productionUpOther").prop('disabled', true);
$("input[name = 'production-up']").change(function () {
var hasTheFieldToBeEnabled = this.value === "other" && this.checked;
$("#productionUpOther").prop('disabled', !hasTheFieldToBeEnabled);
});
CSS
:disabled
{
display: none;
}
Here, all the disabled fields are hidden... But CSS is your friend if that's not what you want ^^
/!\ Careful: IE <8 doesn't support ':disabled', so if you want to support IE 8, you should add a class to the input when disabling it
try this
$("#productionUpOther").hide();
$("input[name = 'production-up']").change(function () {
//check if the selected option is others
if (this.value === "other" && this.checked) {
//toggle textbox visibility
$("#productionUpOther").show();
}
else{
$("#productionUpOther").hide();
}
});
see DEMO
You can directly use ID Selector ("#ID")
$("input#other").change(function () {
$("#productionUpOther").toggle(this.checked);
$("#productionUpOther").prop('required', this.checked);
});

Check/Uncheck checkbox with JavaScript

How can a checkbox be checked/unchecked using JavaScript?
Javascript:
// Check
document.getElementById("checkbox").checked = true;
// Uncheck
document.getElementById("checkbox").checked = false;
jQuery (1.6+):
// Check
$("#checkbox").prop("checked", true);
// Uncheck
$("#checkbox").prop("checked", false);
jQuery (1.5-):
// Check
$("#checkbox").attr("checked", true);
// Uncheck
$("#checkbox").attr("checked", false);
Important behaviour that has not yet been mentioned:
Programmatically setting the checked attribute, does not fire the change event of the checkbox.
See for yourself in this fiddle:
http://jsfiddle.net/fjaeger/L9z9t04p/4/
(Fiddle tested in Chrome 46, Firefox 41 and IE 11)
The click() method
Some day you might find yourself writing code, which relies on the event being fired. To make sure the event fires, call the click() method of the checkbox element, like this:
document.getElementById('checkbox').click();
However, this toggles the checked status of the checkbox, instead of specifically setting it to true or false. Remember that the change event should only fire, when the checked attribute actually changes.
It also applies to the jQuery way: setting the attribute using prop or attr, does not fire the change event.
Setting checked to a specific value
You could test the checked attribute, before calling the click() method. Example:
function toggle(checked) {
var elm = document.getElementById('checkbox');
if (checked != elm.checked) {
elm.click();
}
}
Read more about the click method here:
https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/click
to check:
document.getElementById("id-of-checkbox").checked = true;
to uncheck:
document.getElementById("id-of-checkbox").checked = false;
We can checked a particulate checkbox as,
$('id of the checkbox')[0].checked = true
and uncheck by ,
$('id of the checkbox')[0].checked = false
Try This:
//Check
document.getElementById('checkbox').setAttribute('checked', 'checked');
//UnCheck
document.getElementById('chk').removeAttribute('checked');
I would like to note, that setting the 'checked' attribute to a non-empty string leads to a checked box.
So if you set the 'checked' attribute to "false", the checkbox will be checked. I had to set the value to the empty string, null or the boolean value false in order to make sure the checkbox was not checked.
Using vanilla js:
//for one element:
document.querySelector('.myCheckBox').checked = true //will select the first matched element
document.querySelector('.myCheckBox').checked = false//will unselect the first matched element
//for multiple elements:
for (const checkbox of document.querySelectorAll('.myCheckBox')) {
//iterating over all matched elements
checkbox.checked = true //for selection
checkbox.checked = false //for unselection
}
function setCheckboxValue(checkbox,value) {
if (checkbox.checked!=value)
checkbox.click();
}
<script type="text/javascript">
$(document).ready(function () {
$('.selecctall').click(function (event) {
if (this.checked) {
$('.checkbox1').each(function () {
this.checked = true;
});
} else {
$('.checkbox1').each(function () {
this.checked = false;
});
}
});
});
</script>
For single check try
myCheckBox.checked=1
<input type="checkbox" id="myCheckBox"> Call to her
for multi try
document.querySelectorAll('.imChecked').forEach(c=> c.checked=1)
Buy wine: <input type="checkbox" class="imChecked"><br>
Play smooth-jazz music: <input type="checkbox"><br>
Shave: <input type="checkbox" class="imChecked"><br>
If, for some reason, you don't want to (or can't) run a .click() on the checkbox element, you can simply change its value directly via its .checked property (an IDL attribute of <input type="checkbox">).
Note that doing so does not fire the normally related event (change) so you'll need to manually fire it to have a complete solution that works with any related event handlers.
Here's a functional example in raw javascript (ES6):
class ButtonCheck {
constructor() {
let ourCheckBox = null;
this.ourCheckBox = document.querySelector('#checkboxID');
let checkBoxButton = null;
this.checkBoxButton = document.querySelector('#checkboxID+button[aria-label="checkboxID"]');
let checkEvent = new Event('change');
this.checkBoxButton.addEventListener('click', function() {
let checkBox = this.ourCheckBox;
//toggle the checkbox: invert its state!
checkBox.checked = !checkBox.checked;
//let other things know the checkbox changed
checkBox.dispatchEvent(checkEvent);
}.bind(this), true);
this.eventHandler = function(e) {
document.querySelector('.checkboxfeedback').insertAdjacentHTML('beforeend', '<br />Event occurred on checkbox! Type: ' + e.type + ' checkbox state now: ' + this.ourCheckBox.checked);
}
//demonstration: we will see change events regardless of whether the checkbox is clicked or the button
this.ourCheckBox.addEventListener('change', function(e) {
this.eventHandler(e);
}.bind(this), true);
//demonstration: if we bind a click handler only to the checkbox, we only see clicks from the checkbox
this.ourCheckBox.addEventListener('click', function(e) {
this.eventHandler(e);
}.bind(this), true);
}
}
var init = function() {
const checkIt = new ButtonCheck();
}
if (document.readyState != 'loading') {
init;
} else {
document.addEventListener('DOMContentLoaded', init);
}
<input type="checkbox" id="checkboxID" />
<button aria-label="checkboxID">Change the checkbox!</button>
<div class="checkboxfeedback">No changes yet!</div>
If you run this and click on both the checkbox and the button you should get a sense of how this works.
Note that I used document.querySelector for brevity/simplicity, but this could easily be built out to either have a given ID passed to the constructor, or it could apply to all buttons that act as aria-labels for a checkbox (note that I didn't bother setting an id on the button and giving the checkbox an aria-labelledby, which should be done if using this method) or any number of other ways to expand this. The last two addEventListeners are just to demo how it works.
I agree with the current answers, but in my case it does not work, I hope this code help someone in the future:
// check
$('#checkbox_id').click()

I need an event trigger for a radio button for when it is unchecked because another button is checked

I need an event trigger for a radio button for when it is unchecked because another button is checked.
The code below should demonstrate my dilemma.
If you will notice, there is an onchange event trigger atttached to each radio button and checkbox in the html code. In theory a change in state from checked to unchecked should fire the onchange event.
This happens as expected with the check boxes. If you check one, you get the alert, 'Your item is changed to checked'. If you uncheck it, you get the alert, 'Your item is changed to unchecked'.
With the radio buttons, when you check button one, you get, as expected, the alert, 'Your item is changed to checked' since the button changed from unchecked to checked. However, when you check the second button and the first radio button is changed from checked to unchecked the "onchange" event trigger does not fire and the 'else' alert is not triggered.
So this issue for me is what event is triggered when a radio button gets unchecked by another button being checked?
I appreciate everyone's assistance on this.
--Kenoli
<html>
<head>
<title></title>
<script type="text/javascript">
function clickAction() {
//alert ('Your item changed');
if (this.checked == true) {alert ('Your item is changed to checked');}
else if (this.checked == false) {alert('Your item is changed to unchecked');}
}
</script>
<script type="text/javascript">
function initializeToggles() {
var button1= document.getElementById('button1');
button1.onchange = clickAction;
var box1= document.getElementById('box1');
box1.onchange = clickAction;
var box2= document.getElementById('box2');
box2.onchange = clickAction;
}
</script>
<script type="text/javascript">window.onload = initializeToggles;</script>
</head>
<body>
<input type="radio" name="testRadio" id="button1" >Button one<br/>
<input type="radio" name="testRadio" id="button2" >Button two<br/><br/>
<input type="checkbox" name="testCheckbox" id="box1" >Box one<br/>
<input type="checkbox" name="testCheckbox" id="box2" >Box two<br/><br/>
</body>
</html>
I came here looking for a quick solution for this type of problem, and nuc's answer helped me come up with this:
$(document).ready(function(){
$('input[type=radio]').change(function() {
var selected = $(this);
$('input[type=radio]').each(function() {
if $(this).attr('id') != selected.attr('id') {
console.log( $(this).attr('value') + ' was deselected because ' + selected.attr('value') + ' was clicked.')
}
});
});
});
There is no event for when a radio button gets unchecked. You might be able to use the onpropertychange event, however that's not a standardised event so it might only work in Internet Explorer.
The safest way would be to take care of that in the onchange event. If you want to know which radio button was unchecked, you would have to keep a reference to the currently checked element in a variable.
I slightly modified rthbound's code to handle a group of radio input's, in my case enclosed in a <table>. But this could easily altered for a <div>. Also this code is more compliant with jQuery 1.9. A common class would be better, to take the class from the selected radio and find other radio inputs with the same class, but I'm working with ASP.NET and this is quicker and easier for me.
$(document).ready(function(){
$(document).on("change", "input[type='radio']", function () {
var selected = $(this);
$(this).closest("table").find("input[type='radio']").each(function () {
if ($(this).attr("id") !== selected.attr("id")) {
console.log($(this).attr("value") + " was deselected because " + selected.attr("value") + " was clicked.");
}
});
});
});
I've solved this issue in a generic way:
whenever a radio button is changed:
if they were triggered by this system - we don't want unending loops.
find all its radio button friends
trigger change on them
then I can test for whether the radio button was checked or unchecked.
$(function(){
$('body').on('change', 'input[type="radio"]', function(e, by_other) {
if (!by_other) {
$("input[type='radio'][name='" + $(this).attr('name') + "']")
.not(this)
.trigger('change', true)
}
}
}
(I did translate it from coffeescript to javascript for ya'll.)
The Radio buttons have same name, so we can select them by name.
Because .change() is not effected when the radio is unchecked, so we use .click() instead of.
$('input[name="your-radio-name"]').click(function() {
var $radios = $('input[name="your-radio-name"]');
for (var i = 0; i < $radios.length; i++) {
var radio = $radios[i];
if (radio != this) {
radio = $(radio);
// Process for unchecked radios here
}
}
// Now, process for checked radio
// alert(this.value + ' is checked'); Or
alert($(this).val() + ' is checked');
});

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