Dynamic number of columns

[2002 JI Open Discussion]

By: Oliver Toma - olivertoma

Dynamic number of columns

2003-07-22 03:41

Hi forum,

 

how can i manage a dynamic number of columns? on the client side you have the ability to show/hide columns. how can i design the report due to that problem? do i have do know in advance (means at designing time) which columns should be printed?

 

thanks,

oliver

 

 

 

 

By: Ryan Johnson - delscovich

RE: Dynamic number of columns

2003-07-22 09:43

Do you care whether there's empty space? It's possible to hide columns. If there are only going to be a couple of variations, you could use <printWhen> to control which ones show.

 

Could you be more specific about what you're trying to do?

 

Ryan

 

 

 

 

By: Oliver Toma - olivertoma

RE: Dynamic number of columns

2003-07-23 06:20

Hi Ryan,

 

sound good. I have an applet context with data supplied by a cobol host. in the applets there are tables, which can be influenced by the user. means that columns can be hided/shown (via right mouse-click).

there are only a few variations, so that your model might work, but will the empty space be reduced, or will there be a big gap between two "table-cells"?

 

thanks,

oliver

 

 

 

 

By: Teodor Danciu - teodord

RE: Dynamic number of columns

2003-07-23 06:29

 

Hi,

 

I think the best way is to have some default report

templates stored in XML form and to let the user

alter them at runtime by hidding and moving columns

around.

Changing the position of elements (columns) in a band

implies report design recompilation (revalidation).

 

But I think a better approach is to let users define and store their own report templates derived from

the default ones.

They will reuse those custom templates and will

not be forced to specify the columns every time

they want to run the report. Instead, they could

chose a previously defined template that is already

in a compiled form.

Performance will be much better if they don't have

to recompile the report designs with every execution.

 

I hope this helps.

Teodor

 

 

 

 

 

By: Ryan Johnson - delscovich

RE: Dynamic number of columns

2003-07-23 18:30

Teodor is right - it is cleanest to use different templates for each variation.

 

However, if you really want, you can use <printWhen> and parameters to show/hide columns in different places and of different sizes. Depending on how complicated you make things, you may or may not leave empty space between hidden columns.

 

It would also depend on whether you have control over your JRDatasource from the program or if it comes straight from a ResultSet.

 

I'd go with Teodor's way, myself

Ryan