Hello,
I'm experiencing some weird behaviour (ie: behaviour I do not understand) when it comes to page-breaking reports.
I have a rather complex report that retrieves its data from a webservice.
The data always involves segments having a number of properties, one of which is the "length" that should be
summed for all items in a group. The report does three levels of grouping:
1) The first two on a column of the users choice (it is allowed to have only one level of grouping, in that case the first and second grouping level just group on the same column-value
2) The third level groups all visible columns so that no two rows are identical. To do so, I create an invisible field that contains all values of the visible columns and groups on that.
I realise the explanation may be a bit compact for a good understanding of why I'm trying to do, but a while ago I made a blog entry on how to realise the above with a short example. You can see that at
http://qmino.wordpress.com/2010/05/13/birt-dynamic-column-visibility-grouping-on-visible-columns . This will clarify the situation a lot.
All that works perfectly, however page breaking behaviour is odd to say the least. What I typically *want* to do is something standard such as: "Just fill the paper, and avoid, if possible, to simply add a grouptitle without data on a page." Now, if nothing is hidden and the two outer groupings are active, even letting everying on "auto" results in a nice output with a report containing 336 pages of data.
If I start to hide columns, however, and the inner grouping becomes more active (more rows will appear identical as differt columns will be hidden) the number of rows will decrease. However, the number of pages stays the same (336), as does the location (page) of the titles of the level-1 groups. So basically, I just end up with practically entirely empty pages (see attachments). Some of the pages between 1 and 15 (first new group) have 1 row, some 0. Clearly this is not what I want: it looks ridiculous. Disabling pagebreaks altogether is not an option since the dataset is too large...
How can I resolve this? If it helps I can upload the rptdesign file, but that report definitely will not work on your system as it depends on external datasources.
Suggestions or help are greatly appreciated.
Thank you very much,
Yves
