How to Expand all/Collapse all summary tasks dynamically?

Gantt has some inbuilt .apis which enables you to collapses all and expand all summary tasks bars during run time. Below code will explain you how to use those .apis.

$(document).ready(function () {

var $gantt_container = $('#gantt_container');

$gantt_container.GanttControl({

DataSource: self.jsonData,

.................

................

});

var ganttControl = $gantt_container.data("GanttControl") || $gantt_container.data("radiantqGanttControl");

$("#collapseButton").click(function () {

ganttControl.CollapseAll();

});

$("#expandButton").click(function () {

ganttControl.ExpandAll();

});