Question

Consider the following example: (live demo here)

HTML:

<div class="wrapper">
    <div city_id="1" class="odd">Street Name #1 in city 1</div>
    <div city_id="3" class="even">Street Name #2 in city 3</div>
    <div city_id="2" class="odd">Street Name #3 in city 2</div>
    <div city_id="1" class="even">Street Name #4 in city 1</div>
    <div city_id="1" class="odd">Street Name #5 in city 1</div>
    <div city_id="3" class="even">Street Name #6 in city 3</div>
    <div city_id="2" class="odd">Street Name #7 in city 2</div>
    <div city_id="3" class="even">Street Name #8 in city 3</div>
    <div city_id="1" class="odd">Street Name #9 in city 1</div>
</div>
<select>
    <option value="">Please select...</option>
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
</select>

CSS:

.odd {
    background-color: #777;
}
.even {
    background-color: #aaa;
}

JS:

$(function() {
    $("select").change(function() {
        var city_id = $("option:selected", this).val();
        $("div[city_id]").each(function() {
            $(this).toggle($(this).attr("city_id") == city_id);
        });
    });
});

I would like to keep the alternating coloring even when some rows are hidden.

Is that possible to achieve this with pure CSS ?

If no, how would you do this using Javascript/jQuery ?

Answer 1

Here’s a simple solution . Dynamically change the row’s class while the selected index changes

http://jsfiddle.net/4Bjbc/5/

$(function() {
    $("select").change(function() {
        var city_id = $("option:selected", this).val();
        $("div[city_id]").each(function() {

            $(this).toggle($(this).attr("city_id") == city_id);

        }).filter(":visible")  ///filter the visible ones

          .attr("class",function(index,$class){                

            ///if you don't want to miss out the other classes
            return index%2 == 0 ? $class.replace("odd","even") : $class.replace("even","odd"); 
        });
    });
});