Consider a scenario in which you want to group some data and display it in an AdvancedDataGrid. Now, you open some nodes. And you want to add summaries to the data. Adding summaries means to re-group the data by calling GroupingCollection.refresh(). But the state of open nodes will be lost as new Objects are created for the group nodes while re-grouping.
I’m posting a sample in which the open nodes are preserved.
Open the sample, click on Group data, open some nodes and then click on Add Summary. The nodes which are open will remain open.
Basically, here I’m giving the same UID for the group nodes as they were before (re-grouping). That’s why, the open state is maintained.
Note: This sample will work only if the grouping fields are same for both groupings. It’ll need some tweaking in case the grouping fields are changed.