As I outlined in my Issue with the Cross-section Item post to the forums, the current implementation of the cross-section item carries the following limitation:

The Cross-section item uses the report's data context and cannot be evaluated against detail or group data. The processing engine produces a single instance per each Cross-section item in the report definition, therefore its style or visibility cannot be changed based on data fields.

For invoice (or sales order) style reports this places a severe limitation on the complexity of the report.

One of my current projects requires me to create a report layout that can be run for multiple invoices from multiple customers, where each customer has their own unique set of flags that control what information is included on their invoices for each line item of the invoice.

My current version of this report works great when it is run for a single invoice or invoices from a single customer (or from customers who use the exact same set of print flags) by binding the visibility and begin/end margin values of the lines that start in the groupHeader section, cross through the detailSection, before finally terminating in the groupFooter section.

This can be seen clearly in the 2 attached invoices, one with lots of columns of information (called: Invoice with lots of detail columns.png), and another where the customer has been configured with all the additional information toggled off (called: Invoice with minimal detail columns.png).

Unfortunately, because of the cross-section item's current limitation, when I run the report for both invoices the lines attributes/visibility are set based on the customer flags of the "first" invoice in the group, and do not get reset for subsequent invoices.  This can be seen in the attached file: Behavior when including both invoices.png.

I understand that if a cross-section item begins/ends in a page/report header/footer, then having it's attributes change based on group-specific data would be less than ideal.  But when the line beginning and end points are restricted to a group header and footer, as it always would be for a report layout used for multiple invoices or sales orders, then having that line's attributes change based on the data is the only way to use this functionality for these types of complex reports.

NOTE: While there is a workaround using the attributes/visibility of detail columns, vertical lines in the detail section, and their associated headers and totals textboxes in the groupHeader and groupFooter, it results in an unprofessionial looking report because of the difficulty in getting the variable border and detail vertical lines to line up precisely (and it is very time-consuming to try to implement).

SUMMARY:

Changing the Cross-section item implementation to allow it's data context to be evaluated against detail or group data when the line's terminators are restricted to groupHeader/Footers would allow for its use in more complicated report layouts.

BTW: interally, we refer to these reports as Mighty Morphing Invoice Reports™!!!