how do you select all checkboxes when user clicks a button

Question

i have a form with a "Select All" button and a bunch of checkboxes. i want to have it select all checkboxes when the user clicks the "Select All" button.

is there elegant way in jquery to do this?

EDIT #2: i have isolated the problem down to this code; style="display: none;". if i remove this code it works fine. any ideas?

EDIT: The answers below work in my test form but the button in this case is inside of a form that is inside of a div that only shows up as part of a simpledialog.show(). in this case, for some reason when i click on the button i dont see anything happen:

javascript:

<script type="text/javascript">
$(document).ready(function() {
    $('#sdHc3').simpleDialog({
        showCloseLabel: false,
        open: function() {
            $('#checkboxStatus').html('');
        },
        close: function() {
            var c = [];
            $('#checkboxForm :checkbox:checked').each(function() {
                c.push($(this).val());
            });
            $('#checkboxStatus').html('&nbsp;&nbsp;Checked <b>' + c.join(', ') + '</b>.').show();
        }
    });

});

<script type="text/javascript">
$(function() {
$('#selectAll').click(function() {
        var select_all = (this.value === 'Select All');
        $(':checkbox').attr('checked', select_all);
        this.value = (select_all) ? 'Deselect All' : 'Select All';
    });
});

body:

<div style="display: none;" class="scrollableDiv" id="simpleDialog3">
    <h3>DEMO3</h3>
    <form id="checkboxForm">
    <input type="button" id="selectAll" value="TT" />
    <input type="checkbox" class="chckbx" value="1" /><br />
    <input type="checkbox" class="chckbx" value="1" /><br />
    </form>
    <p>
        <a href="#" class="close">Close</a></p>
</div>

any idea why it wouldn't work in this case?

Answer 1

$(function(){
    $('#myButton').click(function(){
        var select_all = (this.value === 'Select All');
        $('input:checkbox').attr('checked', select_all);
        this.value = (select_all) ? 'Deselect All' : 'Select All';        
    });
});

Try placing this code before your dialog instantiation.

It seems like you may want to switch to jQuery UI Dialog.

Answer 2

Having your button call this when clicked will select all checkboxes on the page:

jQuery("input:checkbox").attr('checked','checked');

You can change the selector ("input:checkbox") to provide better context (and possibly speed up it's execution as well)

• Attr()
• :checkbox

Answer 3

just give all the checkboxes a class, and attach this jQuery to the button:

$(document).ready( function () {
  $('#myButton').click( function() {
    $('.checkbox').attr('checked','checked');
  });
}

Assuming your button has the id="myButton" and your checkboxes have the class="checkbox".

Answer 4

So if your select-all button has an id of select-all you say:

$('#select-all').click(function(){
   $('input:checkbox').attr('checked', 'checked');   
);

Answer 5

In the cases where I've wanted the same functionality, it usually is a table of rows with checkboxes down the side. In that case, you could include this code snippet and then any time there is a checkbox in a header cell, all the associated checkboxes in the column below it will be switched on/off depending on its value.

Assuming HTML like this:

<table>
    <thead>
        <tr>
            <th><input type="checkbox" /></th>
            <th>...</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td><input type="checkbox" name="row[0]" /></td>
            <td>...</td>
        </tr>
        ...
    </tbody>
</table>

Here's the jQuery:

$('th input:checkbox').click(function() {
    var $this = $(this),
        colNum = $this.closest('th').prevAll('th').length,
        checked = $this.attr('checked')
    ;
    $this
        .closest('table')
        .find('tbody > tr')
        .each(function() {
            $(this)
                .children("td")
                .eq(colNum)
                .find("input:checkbox")
                .attr('checked', checked)
            ;
        })
    ;
});

It doesn't require any extra ids or classes or anything and can work for multiple columns of checkboxes, which is nice. Here's a demo page: http://jsbin.com/eqeno