How to perform 'Expand All' and 'Collapse All' in Kendo Tree View on click of Expand button and Collapse button

[Kannan]

Dear Team,

I am new to Kendo control, please help me with this, I already have Tree View as shown in the attachment, Now I have two(Expand  and Collapse) buttons, I need to perform the  'Expand All'  on click of Expand button and 'Collapse All'  on click of  Collapse button.

How to perform 'Expand All' and 'Collapse All' in Kendo Tree View on click of Expand button and Collapse button.

Please help me on this.

 

[Vessy]

Hi Kannan,

You can expand/collapse all nodes of a TreeView by passing the ".k-item" class to the expand() and collapse() methods of the widget. You can see a sample here:
https://dojo.telerik.com/UVoHemup

Regards,
Vessy
Progress Telerik

[Ron Hary]

Looking at your sample - the expand() is expanding a single level on every click and not all the levels at once...

[Vessy]

Hi Ron,

The nested nodes of the TreeView are not bound in the moment when the expand() method is called, this is why only the first level nodes are expanded. A possible approach you can implement is to check whether there are ".k-item .k-i-expand" items (nodes with expand icon) and call the expand() method recursively if there are such. For example: https://dojo.telerik.com/UVoHemup/2

Another approach is to expand the nodes asynchronously without using recursion like demonstrated here: 
https://docs.telerik.com/kendo-ui/controls/navigation/treeview/how-to/nodes/node-async-expand

Regards,
Vessy
Progress Telerik