GroupBreakValue?

rbuser

How can I get the current value of the GroupBreak object in a group footer?
The database query row has moved on so I cant read that. It will be the
last value in the detail band but my detail band is invisible.
I'm just wondering if there is a property of the group somewhere that I can
read?

Regards
Paul

rbuser

Replying to myself

Found tppGroup.BreakValue which is missing from the help.

rbuser

Hmmm - looks like I replied to myself too soon.

BreakValue appears to return the last value pointed to by the query which is
not the current value the break was based on.
So values 1,1,1,1,2,2,2 will a return a BreakValue of 2 when the break from
1 to 2 is detected. When it comes to the end it returns 2 again because the
query is at eof.

Is the current value of the break held anywhere? If not I suggest that the
current BreakValue property is a bug which needs fixing.

Any other way to get the value I want?

Regards
Paul

nicocizik

Hi Paul,

I'm a bit unclear about what you are trying to do. If you need the current
group break value, you can use the TppGroup.OnGetBreakValue event to
retrieve it. If you need to display this value in the group footer, you can
store this value until it changes, then update a component inside the group
footer with the proper break value.

--
Regards,

Nico Cizik
Digital Metaphors
http://www.digital-metaphors.com

rbuser

Hi Nico

I have a totals only report which uses the same query as the full report.
It does this by making the detail band invisible in the totals version so
just the footer totals show. There are two groups and two group footers
with totals. The inner group has a group value which I need to use to
change a label caption in the footer.

If the detail band was visible and printing I could just maintain a local
variable of the breakvalue every time it printed then use this value in the
footer.

I've been using OnGetBreakValue to move the query buffer pointer to the
previous row (able to do this in IBO without interfering with the query row
position) and read the value. On the very last record I dont go to the
prior row, just read the value - unfortunately this bit doesnt work properly
yet.

It still doesnt seem right to me that the BreakValue contains the value for
the next group to be printed instead of the value relevant to the group
footer. This is also inconsistent when it comes to eof. I could see from
the source that it is getting the value from the query which isnt very
helpful since that it wrong and could easily be done in the app code anyway.
I would have liked the BreakValue to have the value just before the break, I
think this would be more logical, useful and consistent - although a little
harder to code;-)

Regards
Paul

nicocizik

Hi Paul,

Grouping in ReportBuilder was originally designed so that the group footer
does not generate until the BreakValue changes. This is basically how the
report engine knows it is time to print the group footer. My suggestion was
to perhaps keep track of this change on your own using a global variable or
a class field in Delphi. You can store the current break value as the
report traverses, then if it changes, you can set the current value to the
component inside the Group footer band and move on to the next group.

--
Regards,

Nico Cizik
Digital Metaphors
http://www.digital-metaphors.com

rbuser

Hi Nico

Fixed it.

I couldnt get your suggestion to work reliably - which may well be my fault.

Also there is the problem that if a group Header is looking at BreakValue it
would be logical to see CurrentValue whereas if it is a group Footer looking
at BreakValue it would be logical to see PriorValue.

Having discovered that tppGroup.PriorValue is public I have used that in my
get text procedure for a label in the group footer with perfect results
:-)))

Regards
Paul