children_detailed.tpl

{* design/admin/templates/children_detailed.tpl *}
{* ... *}
<script type="text/javascript">
YUI(YUI3_config).use('updatepanels', function (Y) {
{/literal}

// lots of code JS here...

{literal}
    // here Y.eZ.updatePanelsHeight is available!
    // it can be passed as a paramater to sortableSubitem.init so that it's called
    // when necessary

YUILoader.require(['datatable', 'button', 'container', 'cookie', 'element']);
YUILoader.onSuccess = function() {
    sortableSubitems.init(confObj, labelsObj, createGroups, createOptions);
};
var options = [];
YUILoader.insert(options, 'js');

});
{/literal}
{undef $section $visible_columns $locales}
</script>
{* ... *}

updatepanels.js

YUI(YUI3_config).add('updatepanels', function(Y) {
    Y.namespace('eZ');
    Y.eZ.updatePanelsHeight = function () {
         // the code
    }
}, '1.0.0', {'requires': ['node']});