How to add custom sorting to AdvancedDataGrid to worked on grouped Data?

I have an advancedDataGrid that I need to add custom sorting to it which overrides the original sort! my sorting should work using a combobox to select ascending and desending from with a sort button! I know this is a bug in flex that its original sorting only works in hierarchical data and not for groupingCollection
the dataProvider of my grid is a flat data. however, in the UI, the user can add grouping to the AdvancedDataGrid. so I want the sort to work on grouped data!
let's say the columns are : country, province, city. population and there is grouping on country and province
so the sorting should do the following:
1) if the user does a descending sort on country: only unitedStates will go up and Canada will go down.
2)if the user does a descending sort on province: the order of the grouping of province will change to Quebec, Ontario, British Columbia
3) if the user does a soring on city: although this is not a grouped column, it should do the sorting on all the cities.

Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

zzynxSoftware engineerCommented:
honeybeepsAuthor Commented:
Thanks zzynx! But would you please tell me how this is related to what I'm looking for? If you explain a little bit maybe I can figure it out
zzynxSoftware engineerCommented:
>> would you please tell me how this is related to what I'm looking for?
You asked
     >> I want the sort to work on grouped data!
That example allows sorting even when grouping is on. (press the button "Group on xxx" buttons).
That's why I thought it could be useful to you.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
honeybeepsAuthor Commented:
I'm busy building another component so I'll close this case for now, and hopefully we will figure it out later :) thanks for the help
zzynxSoftware engineerCommented:
>> I'll close this case for now
OK...depending on what you mean by "closing"
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Adobe Flash

From novice to tech pro — start learning today.