I'm passing in a view model that works with the CheckBoxListFor property and I would like to hide the checkbox section if when I repost to the page there are no check marks ticked. I can show and hide the check box section with no problem using:

$('div.KSearch').hide(); 

or

$('div.KSearch').show();

What I've been trying to do is check the view model which has a List which hold the information for the keyword model. Is there anyway to check if this list has element being passed in within jquery so that I can show or hide the section with something like:

if (('@Model.SelectedKeywords').length) {
    $('div.KSearch').show();
} else {
    $('div.KSearch').hide();
}

but this always shows the section. Any ideas?

I'm passing in a view model that works with the CheckBoxListFor property and I would like to hide the checkbox section if when I repost to the page there are no check marks ticked. I can show and hide the check box section with no problem using:

$('div.KSearch').hide(); 

or

$('div.KSearch').show();

What I've been trying to do is check the view model which has a List which hold the information for the keyword model. Is there anyway to check if this list has element being passed in within jquery so that I can show or hide the section with something like:

if (('@Model.SelectedKeywords').length) {
    $('div.KSearch').show();
} else {
    $('div.KSearch').hide();
}

but this always shows the section. Any ideas?

• javascript
• jquery
• asp-mvc

• bit confused..post your related HTML codes too.. – bipen Commented Sep 3, 2013 at 16:21
• 1 It looks like you're mixing C# with Javascript. .length is the method to check the length of an array in Javascript. If you have a C# List then you would call .Count. – Justin Helgerson Commented Sep 3, 2013 at 16:22
• I tried the .Count before I tried the .length and that throws a null exception on Post if no check boxes were ticked which means I would have to check if the model exists first which gets me back to my original problem – jbolt Commented Sep 3, 2013 at 16:44

2 Answers 2

Something like this?

var len = @Model.SelectedKeywords.Count;

if (len > 0) {
    $('div.KSearch').show();
} else {
    $('div.KSearch').hide();
}

('@Model.SelectedKeywords').length is treated as a string length in javascript, and it's always positive (and true) ;)

Check MVC Model is null or not in jquery

<script type="text/javascript">

    var checkBoxCount = @(Model.SelectedKeywords != null ? Model.SelectedKeywords.Count : 0);
    if (checkBoxCount != 0) {
        $('div.KSearch').show();
    } else {
        $('div.KSearch').hide();
    }

</script>

I hope this will help.