Code:
<script type="text/javascript" charset="utf-8">
// A function to handle "child" checkboxes
function dependantCheckboxes(qID, primaryCodes, secondaryCodes, tertiaryCodes) {
// Identify the elements annd assign classes/attributes
var thisQuestion = $('#question'+qID);
thisQuestion.addClass('with-dependants');
$.each(primaryCodes, function(i, val) {
var thisItem = $('li[id$="X'+qID+val+'"]');
$(thisItem).addClass('level-1 parent-item').attr('data-code', val).attr('data-level', '1');
});
$.each(secondaryCodes, function(i, val) {
var thisItem = $('li[id$="X'+qID+val+'"]');
var thisParent1 = $(thisItem).prevAll('li[data-level="1"]:eq(0)');
$(thisItem).addClass('level-2 parent-item child-item').attr('data-code', val).attr('data-level', '2').attr('data-parent-1', $(thisParent1).attr('data-code'));
});
$.each(tertiaryCodes, function(i, val) {
var thisItem = $('li[id$="X'+qID+val+'"]');
var thisParent1 = $(thisItem).prevAll('li[data-level="1"]:eq(0)');
var thisParent2 = $(thisItem).prevAll('li[data-level="2"]:eq(0)');
$(thisItem).addClass('level-3 child-item').attr('data-code', val).attr('data-level', '3').attr('data-parent-1', $(thisParent1).attr('data-code')).attr('data-parent-2', $(thisParent2).attr('data-code'));
});
// A function to handle the states of child items
function handleChildren(el) {
var thisitem = $(el).closest('li');
var thisCode = $(thisitem).attr('data-code');
var thisLevel = $(thisitem).attr('data-level');
var thisChildren = $('li[data-level="'+(Number(thisLevel)+1)+'"][data-parent-'+thisLevel+'="'+thisCode+'"]', thisQuestion);
// Hide/show the secondary answers accordingly
if (!$(el).is(':checked')) {
$(thisChildren).fadeOut(300, function(e) {
$('input:checkbox', thisChildren).prop('checked', false).trigger('change');
});
}
else {
$(thisChildren).fadeIn(300);
}
}
// Initial states of the secondary answers
$('.parent-item input:checkbox', thisQuestion).each(function(i) {
handleChildren($(this));
});
// A listener on the primary answer to show or hide secondary answers
$('.parent-item input:checkbox', thisQuestion).on('change', function(e) {
handleChildren($(this));
});
}
$(document).on('ready pjax:scriptcomplete',function(){
dependantCheckboxes(
{QID},
['SQ1', 'SQ2', 'SQ3'], // First-level sub-question codes
['SQ11', 'SQ12', 'SQ21', 'SQ22'], // Second-level sub-question codes
['SQ111', 'SQ112', 'SQ113', 'SQ121', 'SQ211', 'SQ212', 'SQ221', 'SQ222', 'SQ223'] // Third-level sub-question codes
);
});
</script>
