CODEWITHSUNDEEP
c#javascriptasp.net-mvc-3
Masriyah
Masriyah

Reputation: 2525

Hiding dropdown list when list is empty

I currently have a dropdown list that is populated on page load and sometimes the dropdown list doesn't contain anything and is empty. I would like the hide the dropdown list whenever there aren't any items in the list. I thought i could do this via javascript but i am not sure what i could be doing wrong because after adding the javascript it stills appear on the page.

dropdown select: 

<select data-bind="options: endReason() ? endReason().SubReasons : [], value: subReasonId, optionsText: 'Text', optionsValue: 'Value', visible: isChecked"
                            name="subReasons">
                        </select>

This is my Javascript:

<script type="text/javascript"> 
function OnClientDropDownOpening(sender, eventArgs) 
{   var combo = $find("<%= subReasons %>"); 
    items = combo.get_items(); 
    if(items.get_count()==0) 
    { 
         eventArgs.set_cancel(true); 
    } 
} 
</script>

Upvotes: 0

Views: 1484

Answers (3)

Louis B.
Louis B.

Reputation: 2368

This should do the job in pure JavaScript:

var select = document.getElementById("select");
var options = select.getElementsByTagName("option");
document.write('Select has ' + options.length + ' options');​

jsFiddle

Upvotes: 0

d3v1lman1337
d3v1lman1337

Reputation: 229

The following requires that you include the jQuery library.

<script type="text/javascript">
$().ready(function () {
    if ($('select[name=subReasons]').length == 0)
        $('select[name=subReasons]').remove();
});
</script>

Upvotes: 0

Darin Dimitrov
Darin Dimitrov

Reputation: 1039588

Why javascript? Seems a complete waste of bandwidth when you could use a condition on the server side and not even render the ddl if there aren't any elements to render:

@if (Model.Items.Count() > 0)
{
    @Html.DropDownListFor(x => x.SelectedItemId, Model.Items)
}

Upvotes: 6

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