Easy way to quick select a whole optgroup in select box

Question

I have a select box in which i can select multiple options. In the select box are multiple optgroups. Is there an easy way to select a whole optgroup at once in javascript?

Solution 1

I suggest using jQuery (or another framework) to quickly handle DOM selections. Give each optgroup a class to make it easier to grab it.

$("optgroup.className").children().attr('selected','selected');

If you want to select the entire group based on the user selecting the group, do the following:

$("optgroup.className").select(function(e) {
  $(this).children().attr('selected','selected');
});

**Both examples are untested pseudo-code, but they should work with minimal changes, if necessary.

If you cannot use a framework, you'll have to traverse the DOM yourself to find the optgroup and children. You could attach a listener to the select element to grab the element being selected then traverse to the children that way, too.

Solution 2

I'm normally against using jQuery for simple jobs like this but I can see its value here. Still, if you prefer a non-jQuery solution that will have the benefits of using no library, introducing no spurious ids or classes and running faster, here is one:

<script type="text/javascript">

function selectOptGroupOptions(optGroup, selected) {
    var options = optGroup.getElementsByTagName("option");
    for (var i = 0, len = options.length; i < len; i++) {
        options[i].selected = selected;
    }
}

function selectOptGroup(selectId, label, selected) {
    var selectElement = document.getElementById(selectId);
    var optGroups = selectElement.getElementsByTagName("optgroup");
    var i, len, optGroup;
    for (i = 0, len = optGroups.length; i < len; i++) {
        optGroup = optGroups[i];
        if (optGroup.label === label) {
            selectOptGroupOptions(optGroup, selected);
            return;
        }
    }
}

</select>

<select id="veg" multiple>
    <optgroup label="roots">
        <option>Swede</option>
        <option>Carrot</option>
        <option>Turnip</option>
    </optgroup>
    <optgroup label="leaves">
        <option>Spinach</option>
        <option>Kale</option>
    </optgroup>
</select>

<input type="button" onclick="selectOptGroup('veg', 'roots', true)" value="Select roots">

If your <optgroup> has an id you could do away with the selectOptGroup function and just pass the optgroup straight into selectOptGroupOptions.

Solution 3

jquery:

$('#myoptgroup option').attr('selected', true);

Solution 4

I was trying to do something similar just now.

I wanted to select an <optgroup>'s <option>s upon clicking the group's label. The first attempt went like this:

$('select > optgroup').click(function () {
    $(this).children().attr('selected', true);
});

This solution half worked...

Upon clicking the <optgroup>'s label all of its children became selected.

BUT when simply clicking an <option> it was still selecting all the other <option>s in the group! The problem was event bubbling, because the <option> is inside the <optgroup> technically you're clicking it too.

Therefore the final piece of the puzzle was to suppress the event bubbling upwards in the event that an <option> was actually clicked instead. The final solution then became:

$('select > optgroup').click(function () {
    $(this).children().attr('selected', true);
});

$('select > optgroup > option').click(function (e) {
    if (!e) var e = window.event;
    e.cancelBubble = true;
    if (e.stopPropagation) e.stopPropagation();
});

Job done!

EDIT

Infuriatingly this doesn't work work in IE8 (and doubtful < IE8 - maybe IE9?)...

It decides to totally ignore click events on both and elements. The only alternative that I can think of is to position elements above the optgroup labels to capture the click, but its probably not worth the effort...

View more solutions

Comments

[blub]

Hmm i was trying to find a solution without jQuery. But looking at the simple way to do it; and the other side: traversing through the dom.... Jquery it is.

[Ben Blank]

@blub — I think a lot of people get into jQuery that way. ;-)

[Brandon Belvin]

Traversing the DOM yourself isn't terribly difficult, but a framework just makes it easier. document.getElementById('selectElementID') would give you the select element itself. Then it's just a matter of traversing its children or you could add an event listener to capture the select event and parse if it's your desired optgroup. If so, then you would traverse the optgroup children and select them as well.

[TalesM]

As tip, in more recent jQuery versions you should use .prop() instead .attr() in this case.