Files
uscogdata/R/categories.R
jaredandClaude Opus 5 12a9be110f feat: advertise 'All Categories' from cog_categories()
A reserved value nobody can discover is a trap, and this is the view
the API's /categories endpoint is built from. Emitted for the two flow
vocabularies only -- cog_balances() returns a stock and has no concept
to sum within.

Also fix test-categories.R to exclude pseudo-category rows from
crosswalk-specific assertions (one row per (category, subtype) pair,
non-empty item_codes, valid subtypes).

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-05 11:43:02 -04:00

94 lines
4.0 KiB
R

# R/categories.R
#' List available spending / revenue categories
#'
#' Returns the category taxonomy exposed by the corpus's
#' `summary_categories` view, grouped to one row per
#' `(category, subtype)` pair. Use this to discover valid `category`
#' values for [cog_spending()] / [cog_revenue()] / [cog_balances()] /
#' [cog_geographic_rollup()] and to audit which Census item codes feed
#' each category.
#'
#' `subtype` COALESCEs the crosswalk's three subtype columns, so it carries
#' `spend_subtype` on expenditure rows, `revenue_subtype` on revenue rows and
#' `balance_subtype` on balance rows. Note that [cog_balances()] itself takes
#' no `subtype` argument — for holdings, `category` is a strict coarsening of
#' `balance_subtype` — but the value is surfaced here because it is the
#' discovery surface downstream consumers build their vocabulary from.
#'
#' @param type Either `NULL` (default, every row: expenditure, revenue and
#' balance), `"spending"`, `"revenue"`, or `"balance"`.
#' @param pattern Optional regex matched case-insensitively against the
#' `category` column (e.g. `"Police"` or `"Tax"`).
#' @return Tibble with columns `category`, `category_type`, `subtype`,
#' `n_codes`, `item_codes` (comma-separated, alphabetical). Sorted by
#' `category_type`, `category`, `subtype`. Includes one row per flow for the
#' reserved pseudo-category `"All Categories"`, which carries `NA` for
#' `subtype`, `n_codes` and `item_codes` because it is a query mode rather
#' than a crosswalk entry — see [cog_spending()]'s `category` argument.
#' @export
cog_categories <- function(type = NULL, pattern = NULL) {
if (!is.null(type)) {
if (!is.character(type) || length(type) != 1L ||
!type %in% c("spending", "revenue", "balance")) {
cli::cli_abort('`type` must be NULL, "spending", "revenue", or "balance".')
}
}
if (!is.null(pattern) &&
(!is.character(pattern) || length(pattern) != 1L)) {
cli::cli_abort("`pattern` must be a length-1 character string or NULL.")
}
con <- .ensure_session()
preds <- character(0)
if (!is.null(type)) {
# Translate user-facing "spending" to the corpus's native "expenditure"
# value so callers don't have to learn Census vocabulary. "revenue" is
# the same in both.
db_type <- if (type == "spending") "expenditure" else type
preds <- c(preds, sprintf("category_type = %s", .sql_lit_chr(db_type)))
}
if (!is.null(pattern)) {
preds <- c(preds,
sprintf("regexp_matches(category, %s, 'i')",
.sql_lit_chr(pattern)))
}
where <- if (length(preds) == 0L) "" else paste("WHERE", paste(preds, collapse = " AND "))
sql <- paste(
"SELECT category, category_type,
COALESCE(spend_subtype, revenue_subtype, balance_subtype) AS subtype,
COUNT(DISTINCT item_code) AS n_codes,
string_agg(DISTINCT item_code, ',' ORDER BY item_code) AS item_codes
FROM summary_categories",
where,
"GROUP BY category, category_type, subtype
ORDER BY category_type, category, subtype"
)
out <- tibble::as_tibble(DBI::dbGetQuery(con, sql))
# The reserved pseudo-category is a query mode, not a crosswalk row, so it
# has no item codes to report -- hence NA rather than 0 for n_codes. It is
# emitted for the two FLOW vocabularies only: cog_balances() returns a stock
# and has no concept argument to sum within.
pseudo <- tibble::tibble(
category = .ALL_CATEGORIES,
category_type = c("expenditure", "revenue"),
subtype = NA_character_,
n_codes = NA_integer_,
item_codes = NA_character_
)
if (!is.null(type)) {
db_type <- if (type == "spending") "expenditure" else type
pseudo <- pseudo[pseudo$category_type == db_type, , drop = FALSE]
}
if (!is.null(pattern) && nrow(pseudo) > 0L) {
keep <- grepl(pattern, pseudo$category, ignore.case = TRUE)
pseudo <- pseudo[keep, , drop = FALSE]
}
if (nrow(pseudo) == 0L) return(out)
out <- rbind(out, pseudo)
out[order(out$category_type, out$category, out$subtype), , drop = FALSE]
}