Summing values in Sencha List via Grouping and displaying in Group Header list item

Could somebody give me a little info on how I might go about adding a s开发者_如何学Pythonummarized value to the header of a grouped list. For example. I have the model

{firstname, lastname}

and say 10 records.

I want to group by lastname, but while I group I'd like to keep track of the number of records in the current grouping and display that in the "Header" or "Group Header". Like this..

Thompson -- 3 Results

David

Susan

Audrey

Smith -- 1 Result

Cassy

I have to do this client-side and can not group or summarize on the server.

Thanks in advance.

I think the only way to do this is to dynamically grouping the list. I have googled for some answers and figured out something similar to it from sencha forum. Its not the solution to your problem, but you can resolve it from the idea discussed there. Here is the link

http://www.sencha.com/forum/showthread.php?104400-Dynamically-adding-removing-grouped-amp-indexBar-to-from-a-List

Hope it will help...