gistfile1.twig

{% block checkbox_hierarchy_widget %}
  <ul class="listless spaced-listless" id="mainList">
        {% for choiceOrOptionGroup,children in form.vars.choices %}
            {% if children is iterable %}
                <ul>
                    {% for child,choiceView in children %}
                        <li>
                            <label class="checkbox">
                                {{ form_widget(form.offsetGet(child)) }}
                                {{ form.offsetGet(child).vars.label }}
                            </label>
                        </li>
                    {% endfor %}
                </ul>
            {% else %}

                {# If not first loop, close previous <li> #}
                {% if not loop.first %}
                    </li>
                {% endif %}

                <li>
                <label class="checkbox">
                    {{ form_widget(form.offsetGet(choiceOrOptionGroup)) }}
                    {{ form.offsetGet(choiceOrOptionGroup).vars.label }}
                </label>
            {% endif %}

            {# Last of the loop, there will be an open <li>, close it. #}
            {% if loop.last %}
                </li>
            {% endif %}
        {% endfor %}
    </ul>

    <script type="text/javascript">
        $("#mainList").children('li').find('input:first').on('change',function(e,isPageLoad){

            var children = $(this).parents('li:first').find('ul').find('input');
            if($(this).is(':checked'))
            {
                children.prop('disabled',false);
                if(!isPageLoad)
                    children.prop('checked',true);
            }
            else
            {
                children.prop('disabled',true).prop('checked',false);
            }
        }).trigger('change',[true]);
    </script>
{% endblock %}