Crystal Reports:
Display array
values better with
"Join" and "Split" functions
Consider this formula:
Join
({?Country}, ", ") // array, delimiter
If the {?Country} parameter contains the values
["Australia", "New Zealand", "Hong Kong"]
the result of this function will be "Australia, New Zealand, Hong
Kong".
The split function can be used to perform the
opposite result: taking "Australia, New Zealand, Hong Kong"
and returning an array. This would be used to pass a multi value parameter
to a subreport.
1) Create a formula to join the list together (as
described earlier)
2) Link that formula to a single value string
parameter in the subreport
3) Modify the record selection formula in the
subreport (with the split function) to:
{Customer.Country} = split({?Pm-@Country List},
", ")
Can you think of a few uses for this?
A somewhat related topic is "Keep Together." One of formatting options on objects and sections in your report is “Keep Together”. Normally this is ticked to say that you
do not want the object split over a page break. For database fields, formulas and even charts and maps that is probably
the way you want your report to behave, so leave the default tick as given.
However, there are two objects that you might need to have behave differently. A crosstab or a subreport can grow dramatically in size during the processing of a
Crystal Report. There may be times when you want the entire object on its own
page, but otherwise, you might want to see as much as you can on the current page, and then show the rest on
subsequent pages.
Untick “Keep Object Together” if you want to see some of the object fit on the current page. You will also need to untick
“Keep Together” for that section in the section formatting.
But, also consider how large objects might
mess all this up. There are three objects that can change size dramatically inside a
report. They are:
-
Memo field
-
Crosstab object
-
Subreport.
If you
place these on your report and they become very large, the “Keep Together”
property can result in the entire object being relocated to the next page.
Sometimes in these situations, you are
happy to see some of the object on the current page and want it to continue
over subsequent pages.
Remember to untick “Keep Together” on the
formatting for the section the object is in. On subreports and memo fields you
will also need to untick “Keep Together” on the object format.
This leads us, obviously, to the related
subject of page breaks between groups. You can do this from the
Format | Section menu. Crystal
Reports: A Beginner’s Guide provides a step-by-step procedure.
Here's a short tutorial on that:
One of the reasons for
creating a group in Crystal Reports is to have each group start on a new page.
There are
several situations which can be easy to control if you understand how the
section expert works with "New Page Before" or New Page
After." You can use either of these properties to set page breaks,
but we find it is simpler to focus on using just one of these.
If you’ve just got one level of group in your
report, set your "New Page Before" on Group Header 1. To get rid
of the blank first page this creates, you also need to suppress the
"Report Header" section.
If you have multiple groups in your report, and you
want a page break for a lower level group (e.g. Group 3), suppress the
higher level group headers, and set "New Page Before" on your
selected group (in this case Group 3). Depending on how often you want to
see the higher level group names, you can put the Group 1 Name and Group 2
Name objects in either the Page Header or the Group 3 Header sections.
You can also make page breaks conditional. This is ideal for fixed
layout reports like invoices and cheques. Use a variable to behave as a line counter and keep track of
the lines as you print them.
In the Page Header: WhilePrintingRecords; Numbervar linecounter:=0;
In Each Printing Section (including details): WhilePrintingRecords;
Numbervar linecounter:=linecounter + 1;
Conditional "New Page Before" in the
details section: WhilePrintingRecords;
Numbervar linecounter;
linecounter>60 //or replace
the 60 with the number of lines you can print
This technique will also work across multiple
subreports. If you are using subreports, you will need to declare the
variables as shared. The prize goes to Trevor Nunes of UpTime
for working this one through with us.
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