Parent and child flags

Question

  <div id="customerServices">
        <input id="s9" type="checkbox" /> Parent element<br/>
            <input id="s15" class="parent-s9" type="checkbox" /> Child element<br/>
            <input id="s16" class="parent-s9" type="checkbox" /> Child element<br/>
        <br/><br/><br/>

         <input id="s10" type="checkbox" /> Parent element2<br/>
            <input id="s151" class="parent-s10" type="checkbox" /> Child element2<br/>
            <input id="s161" class="parent-s10" type="checkbox" /> Child element2<br/>
          <br/><br/><br/>

           <input id="s101" type="checkbox" /> Parent element3<br/>
           <input id="s102" type="checkbox" /> Parent element4<br/>
     </div>

There are checkboxes on the page. I need:

• Check all children if the parent checkbox is selected.
• Uncheck the box if all children are not checked.
• Check the parent if at least one child is checked.

This is some kind of code, but it does not work

  $('input[type=checkbox]').change(function() {
        var id = $(this).attr('id');
        var children = $('.parent-' + id);


        //Is this a child
        if (children.length)
        {
           //Is it checked
             if ($(this).is(':checked'))
             {
                 //Find the parent
                 var className = $(this).attr('class');
                 var pId = className.replace("parent-","");

                 //If the parent is not checked, then check this parent
                 if (!$(pId).is(':checked'))
                     $(pId).attr('checked','checked');
             }

            //Is it NOT checked
            else{
                //Do other childs are not checked too?
               //var className2 = $(this).attr('class');
                //$(className2)
            }
        }
        //If this is a parent, then check all childs
        esle{ 
            children.attr('checked', $(this).attr('checked'));

        }


     });

Answer 1

Here I wrote the code for you: http://jsfiddle.net/PUWZX/4/

Answer 2

I do not check all of your script, but tell me first if you put this code in

$(document).ready(function() {
....
});

and if jquery works on your page?

Answer 3

Try this, http://jsfiddle.net/erick/dd6Qr/

// 1. Check all  childs  if  parent is checked
$("#s9").change(function(){
    if($(this).is(':checked')) {
        var cls = '.parent-' + $(this).attr('id');
        $(cls).attr('checked', true);  
    }
});

$('input[class*="parent"]').change(function(){
    var cls = '.' + $(this).attr('class') + ':checked';
    var len = $(cls).length;
    var parent_id = '#' + $(this).attr('class').split('-')[1];

    // 3. Check parent if at least one child is checked
    if(len) {
        $(parent_id).attr('checked', true);
    } else {
        // 2. Uncheck parent if all childs are unchecked.
        $(parent_id).attr('checked', false);
    }
});