Dynamically shift columns in compiled report

[2004 IR Help]

By: Jeff - jfsbf

Dynamically shift columns in compiled report

2005-09-30 08:03

Is it possible to shift the position of column headers and columns in a compiled report? We have reports that are dynamically built at runtime based on columns user is allowed to see. We would like to use JasperReports for our HTML, CSV and PDF report generation.

 

For instance, one user may see the following:

 

Col1 Col2 Col3

------ ------ ------

xxxx yyyy zzzz

 

 

Another user may only need to see columns 1 and 3:

 

Col1 Col3

------ ------

xxxx zzzz

 

 

Notice how Col3 (and any columns that could be to the right of it shifted left to take up area where Col2 normally is).

 

The only way I can figure out how to do this is that I will have to generate all the JRXML at run-time, compile report and load data. But I would like to somehow take advantage of only using the compiled report if possible.

 

Thanks,

 

Jeff

 

 

 

 

By: Jeff - jfsbf

RE: Dynamically shift columns in compiled report

2005-10-05 07:24

Anybody got a comment on my original question? Teodor? This is a big issue with the project I am currently working on and anyone's ideas or solution will be greatly appreciated.

 

 

 

 

By: Teodor Danciu - teodord

RE: Dynamically shift columns in compiled rep

2005-10-05 07:59

 

Hi,

 

You can later the X coordinate of elements and move

columns around on your compiled report.

Check the "alterdesign" sample provided to see how to

get a hold of specific elements in the report template.

 

But usually this use case scenario where users get

a chance to design their reports at runtime would

best fit dynamically building report template at runtime

like shown in the "noxmldesign" sample provided.

 

If you put the jdf-compiler.jar in the classpath of your

application, there are no additional configurations to

make for runtime compilation and you only lose about

200 milliseconds for each report compilation.

 

But since users will probably won't like to be asked

with every execution how would they want their reports

to look like, you might end up implementing a way

for those users to store their report templates once

they design them the first time and be able to access

predefined reports on subsequent runs.

This is the perfect compromise solution since they

will still have runtime generated report templates based

on their options, but you'll still gain in performance

since you are not going to recreate those with every run

and load them from a temporary storage.

 

I hope this helps.

Teodor

[wiluspyder]

Teodor,

 

I have a question for you.

You mentioned that after creating the dynamic report users can save those as templates.

Can you elaborate on this? Do you have any examples?

 

I'm designing a report where users pick the column that they want to include in the report.

So far I've read that this can be done via:

 

1. Crosstabs: but I haven't figured out how to do it. Is there an example where I can see how crosstabs are used to create a report with diff # of columns depending on the user's selection

 

2. Velocity & JR: I'd like to skip that approach as there is a fair bit of incorporating that into our framework

 

3. Use java to generate the xml just like in the noxmldesgin example.

 

Let me know if there is another way to manage the issue of dynamic # of columns in a report.

Thanks,

 

JW

[Teodor Danciu]

Hi,

 

I was talking about number 3.

And the noxmldesign sample should show you how you can save to a file the report template you have built using the API.

 

Thank you,

Teodor

[lijf]

Hi,

I wonder if there is a number 4 ?

Check the "alterdesign" sample provided to see how to get a hold of specific elements in the report template.

could i just add one column depending on those specific elements so i don't need to write the design from scratch using raw java code!

Post edited by: lijf, at: 2006/11/21 07:59

[suryaprakash26]

hi,

 

Could any please provide me the complete url for accessing the noxmldesign examples (/demo/samples/noxmldesign).

 

thanks in advance,

Surya

[suryaprakash26]

hi,

 

I am unable to locate the examples mentioned (noexmldesign). I need to refer to these as I have to show certain columns in my report dynamically.

 

I was not able to find the above mentioned example in the reports samples, not sure if I am looking at the right location.

 

Anyone who has used/referred to these, pls. point the exact location where the examples would be available.

 

thanks in advance,

surya

[singhipst]

Hi,

 

Can any body please provide sample code to do that.

Means i also wants to change coloumns according to user selection.

How can i create a common template for my report so that using single template i can create diffterent type of report.

Regards:

Ritesh Kumar

[dkvidera]

We've had to deal with this too and have a few solutions.

 

1. If the number of columns is small and the same for all pages(data records) in the report, you can create the maximum number of column elements needed in the jrxml file and then set the unneeded ones to zero width and the needed ones to the correct width within the JasperReport object before sending it to the JasperFillManager.

 

2. If the number of columns is too cumbersome to create the maximum number of elements, you can create a subreport, load the jrxml, change the number of columns, compile the subreport, change the column element's width, and add it to the main report.

 

Code:

InputStream jasperIS = MyReport.class.getResourceAsStream("MySubreport.xml"«»); 
JasperDesign subDesign = JRXmlLoader.load(jasperIS); 
subDesign.setColumnCount(itemCount); 
int columnWidth = SUBREPORT_WIDTH / itemCount; 
subDesign.setColumnWidth(columnWidth); 
JasperReport subreport = JasperCompileManager.compileReport(subDesign); 
JRBand jb = subreport.getDetail(); 
JRElement je = jb.getElementByKey("theTextField"«»); 
je.setWidth(columnWidth); 
... 
parameters.put("subreport", subreport);

 

3. If the number of columns changes for each page(data record) in the report, you will need to use a scriptlet. See my other post on "Changing report element properties in a scriptlet" for infor on how to do this.

 

-doug