Maintain Treeview expanded and selected node state on postbackstate

[murali]

Hello,

I am binding a treeview to a sitemap and I am trying to maintain the expanded and selected node state on a treeview. I have read the knowledgebase article regarding using a cookie to save the state of expanded nodes.How can I save the state of the currently selected node and re select the node on postback? Also, using the cookie approach I have noticed a decrease in performance when refreshing the screen.

[Georgi Krustev]

Hello mm,

You will need to use the same approach chosen for the expanded  nodes. Just wire OnSelect event and in the event handler persist which item is selected, something like this:

function selectNode(e) {
   $.cookie('SelectedNodes', $(e.item).text());
}

Then retrieve the selected item in the Action method, just like the expanded items. Last you will need to select item while rendering the treeview component:

item.Selected = ((string[])ViewData["SelectedNode"]).Contains(item.Text);

Kind regards,
Georgi Krustev
the Telerik team

[murali]

Georgi,

Thanks for the quick response, saving the selected node is working now. I have another question though; The treeview that is bound to the sitemap is located in the site.master. The ViewData items used to refresh the treeview are loaded with the cookie data in the HOME controller.   So, does this mean that I will have to put the code to reload the viewdata items in
every controller that is used in the sitemap in order to refresh the treeview?

Thanks!

[Georgi Krustev]

Hello Murali,

 Unfortunately the way you suggested is the appropriate one in this case. Nevertheless you can try to use Global FIlters, thus you can update ViewData in the Filter, and using global filter you will not need to apply this filter to all Action methods.

Regards,
Georgi Krustev
the Telerik team