How do you sum columns in same view

Question

I have a search component (drag and drop the viewCriteria) with a table.
In the table is a column for an amount (number). I need to sum the amount and put it in the footer.
I have done this many times with master/detail. Lots of info on that on the web as well. Really simple.
In the view:
So I create a transient attribute (sumAmount).
I set the value to Expression and use one of the following (and several others that are not here).
On the screen:
drag SumAmount from the DC onto the footer. (OutputText no label)
OK so far!?
Run and query - (wishful thinking)
Change the query and new totals appear (not that far yet).
I have tried several permutations.
adf.object.sum("Amount")
sum("Amount")
adf.object.ViewVO.getrowset.sum("Amount")
All show absolutely nothing - I have the output text defined in the footer and the footer is displaying fine.
The table also has some dates in the criteria - when I generate the rowImpl - the search panel is rendered useless due to the Date Domain vs Sql Date ( I know how to manage this)
This has to be simple - just need to get a bit of help on it.
I have tried to do this similar to the master/detail (but in this case - no detail). Still no value.
I should be able to create a "formula" column without the use of java rowImpl.

Answer 1

Finally - I have all the pieces - they are (were) as follows.
1) create the View Object.
2) add the summary column (transient) (be sure to get the data type correct (Number or BigDecimal)).
3) create the view object implementation. (the Java tab in the view object - first box)
4) create the view row implementation and expose the accessors. (the Java tab in the view object - second box).
5) use Steve Muench's help to do the summation - it is a bit tricky and it has a depreciated call in it - but it works. (it is easy to modify to fit - just get the right attribute name for the sum & data type - I used Big Decimal)
http://otn.oracle.com/products/jdev/tips/muench/recalctotalvo/RecalcTotalOfRowsInVO.zip (may have to look for the proper link - I found a lot of broken references)
6) add a footer to the table in the search page and drag and output text box into it (all one step with drag and drop) - leave it empty.
7) in the bindings page of the screen - add an attribute binding for the summary column from the Application Module.
8) once the binding is made, go back to the output text box and use the inspector to create an expression and bind the value to "adf bindings" - data - and select the view-backing definition from the binding you just created.
9) if you want to format this to right justified - surround with JSF HTML "panel grid - 1 column width=100% and style= text:align right - I usually do bold as well.
10) sit back, relax and run - it should work.