Question

I want to filter some content using checkboxes.

I’ve managed to do that thanks to an earlier post which I’ve simplified a bit here DEMO.

My problem is that each content item can have more than one category attached.When I select category A and category B and then deselect category B, the content item that have both categories attached are removed.

The project I’m working on is going to contain more than two categories. A content item can have many categories attached

HTML:

<ul id="filters">
    <li>
        <input type="checkbox" value="categorya" id="filter-categorya" />
        <label for="filter-categorya">Category A</label>
    </li>
    <li>
        <input type="checkbox" value="categoryb" id="filter-categoryb" />
        <label for="filter-categoryb">Category B</label>
    </li>
</ul>

<div class="categorya categoryb">A, B</div>
<div class="categorya">A</div>
<div class="categorya">A</div>
<div class="categorya">A</div>
<div class="categoryb">B</div>
<div class="categoryb">B</div>
<div class="categoryb">B</div>

Javascript:

$('input').click(function() {
    var category = $(this).val();

    if (!$(this).attr('checked')) $('.' + category).hide();
    else $('.' + category).show();

});

Answer 1

I think the two most straightforward approaches would be on click of any of the filter checkboxes either:

1. Hide all <div> elements, then loop through the checkboxes and for each checked one .show() the <div> elements with the associated category.

2. Loop through all checkboxes to make a list of the classes to be shown, then loop through the <div> elements, checking each one to see if it has one of those classes and .hide() or .show() as appropriate.

Is there some general selector you can use to get all the <div> elements? Do they have a particular container element, like how all the checkboxes are descendents of “#filters”?

// Solution 1

$("#filters :checkbox").click(function() {
   $("div").hide();
   $("#filters :checkbox:checked").each(function() {
       $("." + $(this).val()).show();
   });
});

Demo: http://jsfiddle.net/6wYzw/41/

// Solution 2

$("#filters :checkbox").click(function() {

   var re = new RegExp($("#filters :checkbox:checked").map(function() {
                          return this.value;
                       }).get().join("|") );
   $("div").each(function() {
      var $this = $(this);
      $this[re.source!="" && re.test($this.attr("class")) ? "show" : "hide"]();
   });
});

Demo: http://jsfiddle.net/6wYzw/42/

I guess the first way is shorter, and easier to maintain…