Jquery to hightlight elements in a list

Question

I have a ol list:

<ol>
<li class="group1">item 1</li>
<li class="group1">item 2</li>
<li class="group2"> item 3</li>
<li class="group3">item 4</li>
<li class="group1">item 5</li>
<li class="group3"> item 6</li>
<ol>

and a set of checkboxes which correspond to the class names

<input type="checkbox" value="group1" />group 1
<input type="checkbox" value="group2" />group 2
<input type="checkbox" value="group3" />group 3

What I want to happen is that when a user clicks on a checkbox to 'tick' it, any li rows which are not checked are fadedOut (change opacity) and then any rows which have the class which matches the value of the checkbox are highlighter (background colour changed to yellow).

So for example if group 3 was clicked, item 4 and item 6 would be highlighted. Then if group 2 was clicked item 3 would be highlighted (item 4 and 6 would remain highlighted). If group 2 was un-ticked, item 3 would become faded out although item 4 and 6 would remain highlighted.

The code I have at the moment is:

$('input').click(function(){
    input = $(this);
    classVal = "." + input.val();
    elements = $(classVal );

    if (input.is(':checked')) {
        elements.css("background-color", "#FFFF00");
    } else {
        elements.css("background-color", "");
    }
});

This handles the highlighting but does not do the fading of the unchecked elements. I know I can change the opacity using css("opacity", 0.33) or fadeTo("slow", 0.33) but not sure how to handle this in the code and where to put it.

If any of my other code can be tidied up also please let me know

Thanks

Answer 1

The jQuery code:

$('input:checkbox').bind('click', function(){
    var checkedClasses = $("input:checked").map(function() {
        return $(this).val();
    });
    var uncheckedOpacity = (checkedClasses.length == 0) ? 1.0 : 0.5;
    $('ol li').css({opacity: uncheckedOpacity, backgroundColor: 'transparent'});
    $.each(checkedClasses, function(index, value){
        $('.' + value).css({backgroundColor: '#ff0', opacity: 1.0});
    });
});

This HTML:

<ol>
    <li class="group1">item 1</li>
    <li class="group1">item 2</li>
    <li class="group2">item 3</li>
    <li class="group3">item 4</li>
    <li class="group1">item 5</li>
    <li class="group3">item 6</li>
<ol>

<form>
    <label><input type="checkbox" value="group1" />group 1</label>
    <label><input type="checkbox" value="group2" />group 2</label>
    <label><input type="checkbox" value="group3" />group 3</label>
</form>

Answer 2

$('input').click(function(){
 input = $(this);
 classVal = "." + input.val();
 elements = $(classVal );

 if (input.is(':checked')) {
     elements.css("background-color", "#FFFF00");
     elements.css("opacity", 1);
 } else {
     elements.css("background-color", "");
     elements.css("opacity", 0.33);
 }
});

What about that? Just add another css attr to elements.

Answer 3

Maybe I'm missing something, but why not just put it right after the line that changes the background color?

$('input').click(function(){
    input = $(this);
    classVal = "." + input.val();
    elements = $(classVal );

    if (input.is(':checked')) {
        elements.css("background-color", "#FFFF00");
        elements.fadeTo("slow", 1.0);
    } else {
        elements.css("background-color", "");
        elements.fadeTo("slow", 0.33);
    }
});

Answer 4

Initially also you want the unselected li elements to be faded. For this purpose you need to use each() function. Please try the following. I have checked this code and it is working fine.

$('input').click(function() {

            $('input').each(function(index) {

                input = $(this);
                classVal = "." + input.val();
                elements = $(classVal);

                if (input.is(':checked')) {
                    elements.css("background-color", "#FFFF00");
                    elements.fadeTo("slow", 1.0);

                } else {
                    elements.css("background-color", "");
                    elements.fadeTo("slow", 0.33);
                }
            });
        });