How change event work on radio buttons - javascript

the change function catch only if radio is checked but not when its unchecked. Why? Should it behave like that? When I click the radio button the other is unchanging so the event should fire, right? Below is the code and jsfiddle. Do I do anything wrong?
HTML:
Option1 <input type="radio" name="choice" id="op1" checked/>
Option2 <input type="radio" name="choice" id="op2"/>
<br><br>
<span id="sp1">Option1</span><br>
<span id="sp2" style="display: none;">Option2</span>
Javascript:
var op2 = $('#op2');
var sp1 = $('#sp1');
var sp2 = $('#sp2');
op2.change(function(){
if(op2.is(':checked')){
sp1.hide();
sp2.show();
}
else{
sp2.hide();
sp1.show();
}
});

You can run your event handler when either checkbox changes:
$('#op2, #op1').change(...
Here's a demo: http://jsfiddle.net/TCt82/
Another way to select this would be by element name since both checkboxes need to have the same name attribute. Selecting by ID will be faster (although you won't be able to see the difference).
UPADTE
If anyone knows the exact reason the change event does not fire on a checkbox after it's been de-selected, posting it as a comment or answer would be great.

Change your selector to get it using the name
$("input[name='choice']").change(function(){
if(op2.is(':checked')){
sp1.hide();
sp2.show();
}
else{
sp2.hide();
sp1.show();
}
});
Working sample http://jsbin.com/UPILuCe/1

Related

Reload div at checkbox click

Is it possible for me to reload a div when a checkbox in the same document is clicked?
<html:checkbox property="checkbox" styleId="checkbox">
<div id="divToBeRefreshed">
//content
</div>
I'd rather do it using pure javascript but ajax is ok too if there isn't another solution.
Well the answer by #karthick is for change event it will reload the content if the checkbox is unchecked also you can use the below code
$('#checkbox').change(function(){
if($(this).is(':checked')){
// Checkbox is checked.
$("#divToBeRefreshed").html('your content');
}else{
// Checkbox is not checked.
}
});
make your id of checkbox is set to
id='checkbox'
Hope this help you
try this
$("#checkbox").on('change',function(){
$("#divToBeRefreshed").html('your content');
});
The change event is sent to an element when its value changes. This event is limited to <input> elements, <textarea> boxes and <select> elements. For select boxes, checkboxes, and radio buttons, the event is fired immediately when the user makes a selection with the mouse.Hope this is what u meant mate
HTML
<input type="checkbox" name="vehicle" value="Bike">I have a bike<br>
<input type="checkbox" name="vehicle" value="Car">I have a car
<div id="divToBeRefreshed">
</div>
JS
$("input[name=vehicle]").on('change',function(){
$("#divToBeRefreshed").html($(this).val());
});
if you want to fire an event when a checkbox is checked / unchecked: use the below code too.
if( $(this).is(':checked') )
Fiddle
http://jsfiddle.net/BzgrW/

Two Checkboxes Being Checked at the Same Time

I have two checkboxes. What I need is when someone checks one of the boxes, it will automatically check the other one as well. And vice versa, if someone unchecks one of the boxes, it unchecks both. This is a bundle package on the form and they can not get one without the other.
<input type="checkbox" id="chk1" name="chk1" value="100">Voicemail<br />
<input type="checkbox" id="chk2" name="chk2" value="50">VM Support
Any help is greatly appreciated!
Why not this?
<input type="checkbox" id="chk1" name="chk1" value="100">
<label for="chk1">Voicemail and VM Support</label>
Assuming you want to only test these two checkboxes (and not every one on the page), you can use a jQuery Multiple Selector to access the onClick event for both. Using this you can test the checked status of the checkbox that was just clicked, and then assign that status of both checkboxes to match the one that was just clicked.
$('#chk1, #chk2').on('click', function(){
var checked = $(this).is(':checked');
$('#chk1, #chk2').attr('checked', checked);
});
Try this
$('#chk1 , #chk2').on('click', function(){
$('#chk1 , #chk2').attr('checked', $(this).is(':checked'))
});
FIDDLE
FIDDLE

Getting a radio button immediately by clicking a label with jQuery

I've got some radio buttons styled to be hidden with the labels visible and styled as I want them.
The problem is when I click a label I don't get the radio button's value on the first click.
If you look here you can see what I mean: http://jsfiddle.net/bQwtK/1/
Is there a way to get the value on the first click?
ANSWER-
Thanks to asawyer and blocco- http://jsfiddle.net/bQwtK/14/
You can get the value with the code here:
$(".label_size").click(function()
{
alert($("#"+$(this).attr("for")).val());
})
Your code was broken - you missed a closing brace in your JavaScript.
http://jsfiddle.net/bQwtK/5/
Clicking the labels works. If you want the value of the radio buttons, remember that the click event refers to the label, not the radio button. You'll have to access the "for" attribute to get the radio button, and then get its value.
Hiya: your jsfiddle don't give any alert please see correct demo here": http://jsfiddle.net/NEu97/2/ & thank a sawyer : http://jsfiddle.net/NEu97/5/
Please let me know how it goes & hope this helps, :)
Jquery Code
$(".label_size").click(function()
{
alert(' clicked value =' + $(this).text());
alert(' correspong value =' + $('#'+$(this).attr('for')).val());
alert("D");
});
​
HTML
<div class="radio">(This is styled to be hidden)
<input name="size" class="radio_size" type="radio" id="radio_size_small" value="small "/>
<input name="size" class="radio_size" type="radio" id="radio_size_medium" value="medium"/>
<input name="size" class="radio_size" type="radio" id="radio_size_large" value="large"/>
</div>
<div class="radio_labels">
<label class="label_size" for="radio_size_small" id="label_size_small">SMALL</label>
<label class="label_size" for="radio_size_medium" id="label_size_medium">MEDIUM</label>
<label class="label_size" for="radio_size_large" id="label_size_large">LARGE</label>
</div>
​

HTML checkbox onclick called in Javascript

I am having a bit of trouble trying to figure out how to get a certain part of my code to work.
<input type="checkbox" id="check_all_1" name="check_all_1" title="Select All" onclick="selectAll(document.wizard_form, this);">
<label for="check_all_1" onclick="toggleCheckbox('check_all_1'); return false;">Select All</label>
This is my HTML which works as it should (clicking the text will click the box). The javascript for it is pretty simple:
function toggleCheckbox(id) {
document.getElementById(id).checked = !document.getElementById(id).checked;
}
However I want the onclick to happen for the input when the label is what makes the checkbox to be clicked. At this current time the onClick js does not go. What is one suggestion on how to do this?
I tried to add the onclick of the input to the onclick of the label but that doesn't work.
Any suggestions/solutions would be wonderful.
How about putting the checkbox into the label, making the label automatically "click sensitive" for the check box, and giving the checkbox a onchange event?
<label ..... ><input type="checkbox" onchange="toggleCheckbox(this)" .....>
function toggleCheckbox(element)
{
element.checked = !element.checked;
}
This will additionally catch users using a keyboard to toggle the check box, something onclick would not.
Label without an onclick will behave as you would expect. It changes the input. What you relly want is to execute selectAll() when you click on a label, right?
Then only add select all to the label onclick. Or wrap the input into the the label and assign onclick only for the label
<label for="check_all_1" onclick="selectAll(document.wizard_form, this);">
<input type="checkbox" id="check_all_1" name="check_all_1" title="Select All">
Select All
</label>
You can also extract the event code from the HTML, like this :
<input type="checkbox" id="check_all_1" name="check_all_1" title="Select All" />
<label for="check_all_1">Select All</label>
<script>
function selectAll(frmElement, chkElement) {
// ...
}
document.getElementById("check_all_1").onclick = function() {
selectAll(document.wizard_form, this);
}
</script>
jQuery has a function that can do this:
include the following script in your head:
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.0/jquery.min.js"></script>
(or just download the jQuery.js file online and include it locally)
use this script to toggle the check box when the input is clicked:
var toggle = false;
$("#INPUTNAMEHERE").click(function() {
$("input[type=checkbox]").attr("checked",!toggle);
toggle = !toggle;
});
That should do what you want if I understood what you were trying to do.

In jQuery, how do I select an element by its name attribute?

I have 3 radio buttons in my web page, like below:
<label for="theme-grey">
<input type="radio" id="theme-grey" name="theme" value="grey" />Grey</label>
<label for="theme-pink">
<input type="radio" id="theme-pink" name="theme" value="pink" />Pink</label>
<label for="theme-green">
<input type="radio" id="theme-green" name="theme" value="green" />Green</label>
In jQuery, I want to get the value of the selected radio button when any of these three are clicked. In jQuery we have id (#) and class (.) selectors, but what if I want to find a radio button by its name, as below?
$("<radiobutton name attribute>").click(function(){});
Please tell me how to solve this problem.
This should do it, all of this is in the documentation, which has a very similar example to this:
$("input[type='radio'][name='theme']").click(function() {
var value = $(this).val();
});
I should also note you have multiple identical IDs in that snippet. This is invalid HTML. Use classes to group set of elements, not IDs, as they should be unique.
To determine which radio button is checked, try this:
$('input:radio[name=theme]').click(function() {
var val = $('input:radio[name=theme]:checked').val();
});
The event will be caught for all of the radio buttons in the group and the value of the selected button will be placed in val.
Update: After posting I decided that Paolo's answer above is better, since it uses one less DOM traversal. I am letting this answer stand since it shows how to get the selected element in a way that is cross-browser compatible.
$('input:radio[name=theme]:checked').val();
another way
$('input:radio[name=theme]').filter(":checked").val()
This works great for me. For example you have two radio buttons with the same "name", and you just wanted to get the value of the checked one. You may try this one.
$valueOfTheCheckedRadio = $('[name=radioName]:checked').val();
The following code is used to get the selected radio button value by name
jQuery("input:radio[name=theme]:checked").val();
Thanks
Adnan
For anyone who doesn't want to include a library to do something really simple:
document.querySelector('[name="theme"]:checked').value;
jsfiddle
For a performance overview of the current answers check here
I found this question as I was researching an error after I upgraded from 1.7.2 of jQuery to 1.8.2. I'm adding my answer because there has been a change in jQuery 1.8 and higher that changes how this question is answered now.
With jQuery 1.8 they have deprecated the pseudo-selectors like :radio, :checkbox, :text.
To do the above now just replace the :radio with [type=radio].
So your answer now becomes for all versions of jQuery 1.8 and above:
$("input[type=radio][name=theme]").click(function() {
var value = $(this).val();
});
You can read about the change on the 1.8 readme and the ticket specific for this change as well as a understand why on the :radio selector page under the Additional Information section.
If you'd like to know the value of the default selected radio button before a click event, try this:
alert($("input:radio:checked").val());
You can use filter function if you have more than one radio group on the page, as below
$('input[type=radio]').change(function(){
var value = $(this).filter(':checked' ).val();
alert(value);
});
Here is fiddle url
http://jsfiddle.net/h6ye7/67/
<input type="radio" name="ans3" value="help">
<input type="radio" name="ans3" value="help1">
<input type="radio" name="ans3" value="help2">
<input type="radio" name="ans2" value="test">
<input type="radio" name="ans2" value="test1">
<input type="radio" name="ans2" value="test2">
<script type="text/javascript">
var ans3 = jq("input[name='ans3']:checked").val()
var ans2 = jq("input[name='ans2']:checked").val()
</script>
If you want a true/false value, use this:
$("input:radio[name=theme]").is(":checked")
Something like this maybe?
$("input:radio[name=theme]").click(function() {
...
});
When you click on any radio button, I believe it will end up selected, so this is going to be called for the selected radio button.
I you have more than one group of radio buttons on the same page you can also try this to get the value of radio button:
$("input:radio[type=radio]").click(function() {
var value = $(this).val();
alert(value);
});
Cheers!
can also use a CSS class to define the range of radio buttons and then use the following to determine the value
$('.radio_check:checked').val()
This worked for me..
HTML:
<input type="radio" class="radioClass" name="radioName" value="1" />Test<br/>
<input type="radio" class="radioClass" name="radioName" value="2" />Practice<br/>
<input type="radio" class="radioClass" name="radioName" value="3" />Both<br/>
Jquery:
$(".radioClass").each(function() {
if($(this).is(':checked'))
alert($(this).val());
});
Hope it helps..
$('input:radio[name=theme]').bind(
'click',
function(){
$(this).val();
});
You might notice using class selector to get value of ASP.NET RadioButton controls is always empty and here is the reason.
You create RadioButton control in ASP.NET as below:
<asp:RadioButton runat="server" ID="rbSingle" GroupName="Type" CssClass="radios" Text="Single" />
<asp:RadioButton runat="server" ID="rbDouble" GroupName="Type" CssClass="radios" Text="Double" />
<asp:RadioButton runat="server" ID="rbTriple" GroupName="Type" CssClass="radios" Text="Triple" />
And ASP.NET renders following HTML for your RadioButton
<span class="radios"><input id="Content_rbSingle" type="radio" name="ctl00$Content$Type" value="rbSingle" /><label for="Content_rbSingle">Single</label></span>
<span class="radios"><input id="Content_rbDouble" type="radio" name="ctl00$Content$Type" value="rbDouble" /><label for="Content_rbDouble">Double</label></span>
<span class="radios"><input id="Content_rbTriple" type="radio" name="ctl00$Content$Type" value="rbTriple" /><label for="Content_rbTriple">Triple</label></span>
For ASP.NET we don't want to use RadioButton control name or id because they can change for any reason out of user's hand (change in container name, form name, usercontrol name, ...) as you can see in code above.
The only remaining feasible way to get the value of the RadioButton using jQuery is using css class as mentioned in this answer to a totally unrelated question as following
$('span.radios input:radio').click(function() {
var value = $(this).val();
});

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