<body>
<input class="forminput" type="checkbox" value="test one" checked="checked" name="VD1">
<br>
<input class="forminput" type="checkbox" value="test two" checked="checked" name="VD2">
<br>
<input class="forminput" type="checkbox" value="test three" checked="checked" name="VD3">
<br>
<input class="forminput" type="checkbox" value="test four" checked="checked" name="VD4">
<br>
<input class="forminput" type="checkbox" value="test five" checked="checked" name="VD5">
<br>
<input id="checkall" type="checkbox" checked="checked" name="checkall">
<input id="copyvalue" class="button" type="button" value="copy test">
</body>
i want to check out if the user don't check one check box then if he click the copy test, it will alert a box saying" you at least check one box."
$(document).ready(function(){
$("#copyvalue").click(function(){
if (!$(.forminput).checked){
alert('teet');
}
});
but the code doesn't work.
Your syntax is wrong, and you're missing a closing brace and parenthesis.
You can write
$(document).ready(function(){
$("#copyvalue").click(function(){
if ($(".forminput:checked").length === 0){
alert('teet');
}
});
});
Note that the selector is a string.
The :checked selector filters the elements to checked checkboxes.
This code checks whether there are any :checked .forminput elements.
Part of this problem is that you're missing a closing brace and parenthesis, the code should look like this,
$(document).ready(function() {
$("#copyvalue").click(function() {
// ...
});
});
As #Luis has pointed out, another problem is that you didn't quote the selector for the ".forminput" elements. If you quote them properly, it will look like this:
if (!$(".forminput").checked){
alert('teet');
}
But this still won't work, because as #SLaks and #james have pointed out, ".checked" is not a property that you can call on the jQuery object.
I will give credit to #SLaks for coming up with the middle part of the code that checks for checked elements, i.e.
if ($(".forminput:checked").length == 0){
alert('teet');
}
The reason why you use the length property of the jQuery object is because every jQuery object is a collection of the elements matched by the selector (see http://api.jquery.com/Types/#jQuery):
A jQuery object contains a collection
of Document Object Model (DOM)
elements that have been created from
an HTML string or selected from a
document.
So if the selector for checked input boxes returns a length 0 jQuery object, it means none of the input boxes were checked.
The reason why you wouldn't want to use the jQuery attr method instead,
$(document).ready(function(){
$("#copyvalue").click(function(){
if (!$('.forminput').attr("checked")){
alert('teet');
}
});
});
Is because the attr method get's the value of the attribute for the first element in the set of matched elements. So if every input box except for the first one were checked, the code would trigger a false alert.
the selectors need to be quoted,and checked is a selector rather than a method.
$(document).ready(function(){
$("#copyvalue").click(function(){
if ($(".forminput:checked").length==0){
alert('teet');
}
});
});
Related
I am trying to make a selector available, only if a check box, or more than one are checked. The selector should go back to being disabled if the user unchecks all the checkboxes.
I was trying to implement my solution from this response (that it works perfect for one checkbox paired with any other selector) ; however, when I implement it like this:
$(document).ready(function(){
var enable_sel = function(){
$("#pizza_kind").prop("disabled", !$(":checkbox").prop("checked"));
};
enable_sel();
$(":checkbox").change(enable_sel);
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form>
<input type="checkbox" id="p1" name="p1">
<input type="checkbox" id="p2" name="p2">
<input type="checkbox" id="p3" name="p3">
<select name="pizza_kind" id="pizza_kind">
<option>(choose one)</option>
<option>"Hawaian"</option>
<option>"Peperonni"</option>
<option>"Another"</option>
</select>
</form>
I got the selector disabled, but it seems that is only reacting to the first checkbox, not the rest of them.
I couldn't make this work in the javascript/html snippet, don't know why.
I am currently using Flask and jquery 3.6.0
What am I doing wrong?
When you read a prop from a collection it will only ever select the first one. It is not going to randomly pick the one you want, so you need to tell it exactly what to pick.
So select the checked checkboxes and check the length. To do this use :checked in the selector and it will pick the ones that are checked.
$(document).ready(function(){
var enable_sel = function(){
$("#pizza_kind").prop("disabled", !$(":checkbox:checked").length);
};
enable_sel();
$(":checkbox").change(enable_sel);
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form>
<input type="checkbox" id="p1" name="p1">
<input type="checkbox" id="p2" name="p2">
<input type="checkbox" id="p3" name="p3">
<select name="pizza_kind" id="pizza_kind">
<option>(choose one)</option>
<option>"Hawaian"</option>
<option>"Peperonni"</option>
<option>"Another"</option>
</select>
</form>
How to pass this kind of HTML input to JavaScript so that it recognizes these array values?
<input type="checkbox" id="collection[]" value="0">
<input type="checkbox" id="collection[]" value="1">
<input type="checkbox" id="collection[]" value="2">]
The only idea I have (never played with js this way, tbh) is to reach it through:
$("#collection").val();
But I got undefined error. I have no other idea how to make javascript recognize that variable collection is an array and has to passed as such.
Thanks in advance!
Remember, IDs need to be unique within your document. So set by 'name' not by id.
You can use
$('#someid').is(":checked");
for individually checking each checkbox, or loop through them with a jQuery selector
To loop through them set
<input type="checkbox" name="checkboxes" value="0">
<input type="checkbox" name="checkboxes" value="1">
<input type="checkbox" name="checkboxes" value="2">
Then with jQuery,
$('input[name=checkboxes]:checked').each(function(i, e) {
e.val(); //The value of the checkbox that is selected
});
You cannot have Duplicate Ids. Though duplicate IDs will give you desired output in this case, it is invalid to use them for multiple elements.
<input type="checkbox" name="collection[]" value="0">
<input type="checkbox" name="collection[]" value="1">
<input type="checkbox" name="collection[]" value="2">
There are many ways you can access array based elements.
jQuery .map(): Alternative is .each()
Demo
$("[name='collection[]']").map(function(){return $(this).val();}).get()
Working Demo for checking checked inputs.
To get the checked checkbox,
$('input').change(function () {
console.log($("[name='collection[]']:checked").map(function () {
return $(this).val();
}).get());
});
$("#collection")
It mean's ,"Find me an element which id's equal collection on page" , of course it can't find anything. You can use .each function and you can use checkboxes attributes. For example ;
var myCheckBoxArray = []
$("input[type='checkbox']").each(function(i,elm){
myCheckBoxArray.push(elm);
});
Could someone please take a look at this?
You'll see the first alert prints -1 whereas I was expecting 1. Anyone know why?
Basic code from the fiddle:
<input type="checkbox" value="0" />0
<input type="checkbox" value="1" />1
<input type="checkbox" value="2" />2
<input type="checkbox" value="3" />3
alert($(':checkbox').index("input[value='1']"));
alert($(':checkbox').index("input[value='0']"));
You have the selectors reversed:
Example: http://jsfiddle.net/RaV35/
// element---v collection----------v
alert($("input[value='0']").index(":checkbox"));
alert($("input[value='1']").index(":checkbox"));
When passing the index()[docs] method a selector, the individual element for which you want the index is the element against which .index() is invoked.
The selector you pass to .index() represents the collection against which the element in the original jQuery object is tested.
When the original jQuery object (on the left) also contains a collection, only the first one is tested for its index against the selector on the right. That's why the one with value="0" was working.
// v--- only the first is tested (and it has value="0")...
$(':checkbox').index("input[value='0']")
// ----------------------^ ...and it is at index 0 of this "collection"
alert($(':checkbox[value='1']').index());
alert($(':checkbox[value='0']').index());
You need to pass it a jQuery object: http://jsfiddle.net/ybKzJ/1/
alert($(':checkbox').index($("input[value='1']")));
alert($(':checkbox').index("input[value='0']"));
Edit:
No that doesn't seem right as the second one is working just fine.
...curious...
I'm not sure I understand why you have to use index() at all. Why not just put it all in the selector:
$('input:checkbox[value="2"]');
You can see it work in this fiddle: http://jsfiddle.net/jfriend00/Xa6hA/
If you did want to do it in multiple stages, it would be more logical to me to do it like this:
$('input:checkbox').filter('[value="3"]');
This gets all the checkboxes, then filters that list down to just the ones with value="3" which seems a lot more intuitive than the way index() appears to work.
I'm relatively new to Prototype JS (v1.7), and I'm stuck on something. I'm trying to detect when a change in the radio button selection occurs. Here's the code:
Radio buttons:
<input class="amounts" type="radio" name="amount" id="amount-1" value="1" />
<input class="amounts" type="radio" name="amount" id="amount-2" value="2" />
<input class="amounts" type="radio" name="amount" id="amount-3" value="3" />
Javascript:
Here's a stab I took at it, which doesn't work:
Event.observe($$('amounts'), 'change', function(event) {
alert('change detected');
});
When the form loads, no radio buttons are checked. I'd like the Javascript to detect these events:
A radio button is selected when none was previously selected
The radio button selection changes
Any help would be greatly appreciated.
It doesn't work because $$ returns an array of elements and Event needs a single element. Also $$('amounts') doesn't match any elements, there are no <amounts> tags.
A better way is to use a single ancestor element which is easy to identify.
<form id="amounts-form">
<input class="amounts" type="radio" name="amount" id="amount-1" value="1" />
<input class="amounts" type="radio" name="amount" id="amount-2" value="2" />
<input class="amounts" type="radio" name="amount" id="amount-3" value="3" />
</form>
Now there is a unique ID to work with we can use Event.on
$('amounts-form').on('change', '.amounts', function(event) {
alert('change detected');
});
Notice the events are being filtered by '.amounts', the period says to use the class name.
If you're using FireBug for FireFox or Chrome's developer tools then you can test parts of your script directly in the console. It really helps to find if a selector is matching the elements you think it is by typing $$('.amounts')
Alternegro's answer attempts to use an iterator to attach the event handler directly to the "amount" radio elements but doesn't work for a few reasons:
The "$" function doesn't take css selectors as parameters, only ids. Use "$$" instead.
The css "id" attribute selector should include square braces "[]". It's also spelled wrong. "amounts-" should be "amount-" to match the ids in the example. Or just use a class selector instead: ".amounts".
There is no "change" method that can be called on enumerables. Use invoke or some other enumerable method instead.
This one should work:
$$("[id^=amount-]").invoke(
'on',
'change',
function(){alert("hello " + this.id)}
)
(YMMV using "this" in the event handler. I only checked the code in Firefox)
Its more efficient to just give those checkboxes the same class but u can also try
$("id^=amounts-").change(function(){alert("blah blah")})
i want to select a checkbox when a button is clicked.
<form action="" method="post" id="form2">
<input type="checkbox" id="checkone" value="one" name="one" />
<input type="button" value="Click me" id="buttonone"/>
</form>
when i tried the following, the checkbox was not getting selected
$('#buttonone').click(function() {
$('#checkone').checked=true;
});
then i tried:
$('#buttonone').click(function() {
document.getElementById('checkone').checked=true;
});
this time the checkbox got selected. why isn't it getting selected with the jquery $ function?
Try
$('#checkone').attr('checked', true);
or
$('#checkone').get(0).checked = true;
or
$('#checkone')[0].checked = true; // identical to second example
The reason your first code didn't work is because you were trying to set the checked property on a jQuery object which will have no visible effect as it only works on the native DOM object.
By calling get(0) or accessing the first item [0], we retrieve the native DOM element and can use it normally as in your second example. Alternatively, set the checked attribute using jQuery's attr function which should work too.
You need to use .attr() for the jQuery object, like this:
$('#buttonone').click(function() {
$('#checkone').attr('checked', true);
});
But it's better to do it the DOM way, like this:
$('#buttonone').click(function() {
$('#checkone')[0].checked = true; //get the DOM element, .checked is on that
});
Or, completely without jQuery:
document.getElementById('buttonone').onclick = function() {
document.getElementById('checkone').checked = true;
};
None of these answers worked for me because I incorrectly had multiple radios with the same name attributes:
<div id="group-one">
<input type="radio" name="groups" value="1" checked="checked" />
<input type="radio" name="groups" value="2" />
</div>
<div id="group-two">
<input type="radio" name="groups" value="1" checked="checked" />
<input type="radio" name="groups" value="2" />
</div>
Javascript won't recognize the checked attribute (obviously). This was a result of using include to add a similar section of HTML multiple times. Obviously, clicking on a radio button will uncheck the radio toggles with the same name.
Here's a jsfiddle to show that two radio elements can have the attribute checked but only the last one is actually checked:
http://jsfiddle.net/bozdoz/5ecq8/
Again, pretty obvious, but possibly something to watch out for: remove id and name attributes from files that you intend to include into other files multiple times.
Try
$('#checkone').attr('checked', true);
You don't have direct access to DOM object properties because jQuery operates on collections ($(selector) is an array). That's why you have functions defined to manipulate the contents of the returned elements.
try
$('#checkone').attr('checked', true);
cleary googling for "jquery check a checkbox" was the way to go
Or you could simply do
$('#buttonone').click(function() {
$('#checkone')[0].checked=true;
});
It is because ".checked" is not part of jQuery and you are trying to use it on a jQuery object. If you index a jQuery object at [0] you get the raw Javascript object which ".checked" exists on.
More here: http://phrappe.com/javascript/convert-a-jquery-object-to-raw-dom-object/
try this
$('#buttonone').click(function() {
$('#checkone').prop('checked', true);
});