Expressions and functions

The safe expression language: fields, arithmetic, conditions, sum, count, avg, page subtotals, running totals, date and string functions.

Fields, visibility rules, filters and text templates use a small, safe expression language: arithmetic, comparisons, && || ! ?? and ?:, member access (customer.name, items[0]) and the functions below. It has no access to globals and cannot assign. In text, write expressions in braces with an optional format after a colon: "{sum(amount):#,##0}원".

price * qty                         arithmetic
amount >= params.minAmount           comparison with a parameter
customer.name ?? '(미지정)'           member access and fallback
qty > 10 ? '대량' : '일반'             condition
sum(amount)                          aggregate over the band's scope
sum(amount, 'page')                  page subtotal
sum(amount) / sum(amount, 'report')  share of the grand total
format(date, 'yyyy년 M월 d일 (ddd)')  2026년 10월 15일 (목)
koreanAmount(1230000)                일금 일백이십삼만원정
bizNo('7928703276')                  792-87-03276
{page} / {pages}                     page x / y in a text template

Variables

Name	Type	Description
`page, pages`	`number`	Page number and page count (per group with resetPageNumber).
`rowNum`	`number`	Row number within the group (or report).
`rowIndex`	`number`	Row number within the report.
`groupKey, groupLevel`	`unknown, number`	Current group value and depth.
`now`	`Date`	Time the report was laid out.
`params`	`object`	Parameter values: params.from.
`row, rows, allRows, data`	`object, array`	Current row, rows in scope, all rows, the whole data object.

Aggregates and scopes

The scope is the second argument: 'group' (the current group), 'page' (rows on the current page — page subtotals) or 'report' (every row). Without it, aggregates use the band's natural scope: the group in group bands, the page in page bands, the whole report elsewhere.

Name	Type	Description
`sum(expr, scope?)`	`number`	Sum over the scope.
`avg / min / max(expr, scope?)`	`number`	Average, minimum, maximum.
`count(expr?, scope?)`	`number`	Rows (or non-empty values).
`distinct(expr, scope?)`	`number`	Number of different values.
`first / last(expr, scope?)`	`unknown`	Value of the first / last row.
`runningSum(expr, scope?)`	`number`	Sum up to and including the current row (default scope report).

Functions

Name	Type	Description
`format(v, f)`	`string`	Format a number or date: format(date, "yyyy-MM-dd").
`koreanAmount(n) / korean(n)`	`string`	1230000 → 일금 일백이십삼만원정.
`bizNo(v), phone(v)`	`string`	1234567890 → 123-45-67890; 0212345678 → 02-1234-5678.
`round / floor / ceil(v, digits?)`	`number`	Rounding to digits after the point.
`abs, number, string`	`—`	Conversions.
`upper, lower, trim, len, left, right, substr, replace, concat, padStart, join`	`string`	Text functions.
`iif(c, a, b), coalesce(...), isEmpty(v)`	`—`	Conditions and fallbacks (?: and ?? work too).
`date, today, now, year, month, day, addDays, dateDiff, ymd`	`—`	Dates.
`groupSum(rows, key, value), groupCount(rows, key)`	`array`	Totals per key, handy as a chart source.
`min2(a, b), max2(a, b)`	`number`	Smaller / larger of two values.