Subreport calculations for Master - Detail with visibilty of subreport set to false

rbuser

I have a Master-Detail setup in Dade, and I am using a subreport to do
calculations based upon the detail data. I then transfer over the
calculated statistics over to the main report through the setting of
global variables. I always had in mind to set the subreport visibility
to false once I worked out the calculations. However, now I find that
when I set the visibility to false, the calculations do not work. I
guess the OnCalc events for the variables in the detail subreport never
fire when visibility is false.

How can I achieve what I am trying to do? I basically want to show
some summary information on the main report which is based upon
processing through transaction records for every record in the main
report, but I do not want to show all the detail records.

--

rbuser

Some more information:

I also do not want to show the main detail band, yet I am trying to do
calculations in the summary band based upon the data in the detail
band. If I set the main detail band visibility to false, the number
being calculated in the summary band goes to zero. How do I do
calculations based upon data traversal without showing all the records?
Is there an event perhaps that I could be using instead of using a calc
variable to do the calculations?

--

rbuser

More Information:

What I am trying to do is calculate the number of customers who failed
to make a monthly payment for at least 60 days.

The main report processes the loan records, and the subreport processes
transactions, filtering to include only payment transactions.

On the main report is a calc variable called NrFailedPmts. The basic
code in this variable looks like this:

{Handle Loans That Never Made Any Payment}
if Transactions.FieldObjects['TransNo'].IsNull then
begin
if ((Trunc(CurrentDate) - Trunc(Loans['DateT'])) >= MaxDaysLate)
and not CustCounted then
begin
Value:=Value+1;
CustCounted:=true;
end;
end
else {The Subreport takes care of calculating gTimesVeryLate}
begin
if (gTimesVeryLate>0) and Not CustCounted then
begin
Value:=Value + 1;
CustCounted:=true;
end;
end;
gTimesVeryLate:=0; {Needs To Be Reset Before Each Record Is Processed}

If the main detail band is visible, it seems to work. However, if I
set the Main Detail band visibility to false, this calc field shows
zero. I suspect this probably happens because setting the main report
detail band visibility to false causes the subreport detail band not to
process, which is responsible for setting the global variable
gTimesVeryLate.

How can I hide the main detail band, yet still process the transactions
for each loan record so that I can do the calculations that I need and
show them in the summary band?

nicocizik

Hi David,

When setting the subreport's visibility to False, in addition to not
printing the subreport and firing events the dataset is also not
traversed. This makes it impossible to make running calculations on
non-visible (non-generating) reports.

I can think of two ways of working around this. First you could
pre-calculate the values needed manually in Delphi code before printing
the report(s). Second, you could run the report twice, first with the
subreport visible to make the proper caluclation, save these calculated
values, then run the report again with the subreport visible set to false.

rbuser

Nico Cizik (Digital Metaphors) wrote:

Do you think this could be done with a two pass report, where I turn do
something like:

if Report.SecondPass then Report.Detail.Visibility:=false;

What event do you suggest to do this so that I get the timing right?

--

rbuser

Hi Nico.

I have been able to suppress the subreport simply by setting the header
and detail band visible property to false on the subreport page. The
calculations seem to be going through just fine.

However, I still need to suppress the main report detail band. If I
set its visibility to false, then the subreport never processes. I
have tried making it a 2 pass report, and then setting
Report.Detail.Visible:=false in OnEndFirstPass and also
OnStartSecondPass events, but the detail records still are displayed.

Any ideas on how I can manage this in RAP? This is a special report
for one customer using an interface like the End User demo. Using
Delphi Code is not much of an option for this report. I want to do it
all in RAP.

David.

nicocizik

Perhaps instead of hiding the entire detail band, place each component
in the detail band inside a region and hide the region. Be sure
DetailBand.PrintHeight is phDynamic.

rbuser

Hi Nico.

Nice idea. This is getting me very close.

I put the following in the OnStartSecondPass event:

Report.Detail(Region1).Visible:=false;

The detail of the report flashes on the screen, then disappears.

However, I am experiencing some weird behavior now. The report runs the
first time, but if I try to run the report again, it does not run. I
get the search parameters where I can enter a date range, but when I
select ok, the search box disappears and nothing happens. If I exit my
application and restart it, the report will run the first time, but
trying to run the report again does not work.

If I go back and comment out this single line that I have placed in the
OnStartSecondPass event, exit the application, restart app, then run
report, it runs as expected as many times as I need.

Customer will not like running report only once. Any ideas on how to
fix this?

nicocizik

Hi David,

Sorry for the delay in this response. Before running the report again,
you need to be sure to set the Region.Visible back to True so the
calculations can be made again. This is my guess to what is causing the
problem. Perhaps in an early event such as OnInitializeParameters.