Running totals per page

Accounting reports often show “carried forward” at the bottom of each page and “brought forward” at the top of the next. page.regions makes that possible.

For every data region (by its id), page.regions.<regionId> has:

Property	Rows
rows	detail rows printed on this page
before	rows on earlier pages
through	rows up to and including this page

Put the brought-forward line in a region header with repeatHeaderOnEachPage and canShrink, and the carried-forward line in the page footer:

region header:  {{ sum(page.regions.lines.before, 'debit') }}   visible: page.number > 1
page footer:    {{ sum(page.regions.lines.through, 'debit') }}  visible: page.number < page.count

• In page headers and footers the values are complete for the page, because the page is laid out before they are filled in.
• In body bands, rows and through only include rows placed so far on the current page.
• page.count is the total number of pages, available in every band.

The examples/shared/journal-entry.template.json file in the repository is a full example with debit and credit columns.