tabyl uses labels (#575)

* Import `%||%` from rlang.

* Add support for displaying the label attribute for column name.

* Reduce space

* Style code (GHA)

* style

* Handle 2-3 ways tabyl as well.

* Clarify explanation comments

Co-authored-by: Sam Firke <[email protected]>

* Update NEWS.md

* Update NEWS.md

* reword breaking change

---------

Co-authored-by: olivroy <[email protected]>
Co-authored-by: Sam Firke <[email protected]>

NAMESPACE

@@ -69,6 +69,7 @@ importFrom(lubridate,second)
 importFrom(lubridate,ymd)
 importFrom(lubridate,ymd_hms)
 importFrom(magrittr,"%>%")
+importFrom(rlang,"%||%")
 importFrom(rlang,dots_n)
 importFrom(rlang,expr)
 importFrom(rlang,syms)

NEWS.md

@@ -6,6 +6,9 @@ These are all minor breaking changes resulting from enhancements and are not exp
 
 * When using `row_to_names()`, when all input values in `row_number` for a column are `NA`, `row_to_names()` creates a column name of `"NA"`, a character, rather than `NA`. If code previously used relied on a column name of `NA`, it will now error. To fix this, rely on a column name of `"NA"`.
 
+* When `tabyl()` is called on a data.frame containing labels, it now displays the label attribute as the name of the first column in the the resulting `tabyl` object (@olivroy, #394). This may break subsequent code that refers to the output of such a `tabyl` by column name. To maintain the previous behavior of ignoring variable labels, you can remove the labels with a function like `haven::zap_labels()` or `labelled::remove_labels()` before calling `tabyl()`.
+
+
 ## New features
 
 * A new function `paste_skip_na()` pastes without including NA values (#537).

R/get_dupes.R

@@ -22,7 +22,7 @@
 #' mtcars %>% get_dupes(-c(wt, qsec))
 #' mtcars %>% get_dupes(starts_with("cy"))
 #' @importFrom tidyselect eval_select
-#' @importFrom rlang expr dots_n syms
+#' @importFrom rlang expr dots_n syms %||%
 get_dupes <- function(dat, ...) {
   expr <- rlang::expr(c(...))
   pos <- tidyselect::eval_select(expr, data = dat)

R/print_tabyl.R

@@ -1,5 +1,4 @@
 #' @export
-
 print.tabyl <- function(x, ...) {
   print.data.frame(x, row.names = FALSE)
 }

R/tabyl.R

@@ -66,7 +66,6 @@ tabyl.default <- function(dat, show_na = TRUE, show_missing_levels = TRUE, ...)
     var_name <- names(dat)
   }
 
-
   # useful error message if input vector doesn't exist
   if (is.null(dat)) {
     stop(paste0("object ", var_name, " not found"))
@@ -76,6 +75,13 @@ tabyl.default <- function(dat, show_na = TRUE, show_missing_levels = TRUE, ...)
     var_name <- paste(var_name, collapse = "")
   }
 
+  # Try to retrieve label
+  if (is.data.frame(dat)) {
+    var_label <- attr(dat[, var_name], "label", exact = TRUE) %||% var_name
+  } else {
+    var_label <- attr(dat, "label", exact = TRUE) %||% var_name
+  }
+
   # if show_na is not length-1 logical, error helpfully (#377)
   if (length(show_na) > 1 || !inherits(show_na, "logical")) {
     stop("The value supplied to the \"show_na\" argument must be TRUE or FALSE.\n\nDid you try to call tabyl on two vectors, like tabyl(data$var1, data$var2) ? To create a two-way tabyl, the two vectors must be in the same data.frame, and the function should be called like this: \n
@@ -133,8 +139,8 @@ tabyl.default <- function(dat, show_na = TRUE, show_missing_levels = TRUE, ...)
       dplyr::mutate(percent = n / sum(n, na.rm = TRUE)) # recalculate % without NAs
   }
 
-  # reassign correct variable name
-  names(result)[1] <- var_name
+  # reassign correct variable name (or label if it exists)
+  names(result)[1] <- var_label
 
   # in case input var name was "n" or "percent", call helper function to set unique names
   result <- handle_if_special_names_used(result)
@@ -238,10 +244,11 @@ tabyl_2way <- function(dat, var1, var2, show_na = TRUE, show_missing_levels = TR
     result <- result[c(setdiff(names(result), "NA_"), "NA_")]
   }
 
-
-  result %>%
-    data.frame(., check.names = FALSE) %>%
-    as_tabyl(axes = 2, row_var_name = names(dat)[1], col_var_name = names(dat)[2])
+  row_var_name <- names(dat)[1]
+  col_var_name <- names(dat)[2]
+  names(result)[1] <- attr(dat[, 1], "label", exact = TRUE) %||% names(result)[1]
+  data.frame(result, check.names = FALSE) %>%
+    as_tabyl(axes = 2, row_var_name = row_var_name, col_var_name = col_var_name)
 }
 
 
@@ -250,6 +257,10 @@ tabyl_3way <- function(dat, var1, var2, var3, show_na = TRUE, show_missing_level
   dat <- dplyr::select(dat, !!var1, !!var2, !!var3)
   var3_numeric <- is.numeric(dat[[3]])
 
+  # Preserve labels, as attributes are sometimes dropped during transformations.
+  var1_label <- attr(dat[, 1], "label", exact = TRUE)
+  var2_label <- attr(dat[, 2], "label", exact = TRUE)
+
   # Keep factor levels for ordering the list at the end
   if (is.factor(dat[[3]])) {
     third_levels_for_sorting <- levels(dat[[3]])
@@ -277,7 +288,14 @@ tabyl_3way <- function(dat, var1, var2, var3, show_na = TRUE, show_missing_level
     dat[[2]] <- as.factor(dat[[2]])
   }
 
-  result <- split(dat, dat[[rlang::quo_name(var3)]]) %>%
+  result <- split(dat, dat[[rlang::quo_name(var3)]])
+  # split() drops attributes, so we manually add back the label attributes.
+  result <- lapply(result, function(x) {
+    attr(x[[1]], "label") <- var1_label
+    attr(x[[2]], "label") <- var2_label
+    x
+  })
+  result <- result %>%
     purrr::map(tabyl_2way, var1, var2, show_na = show_na, show_missing_levels = show_missing_levels) %>%
     purrr::map(reset_1st_col_status, col1_class, col1_levels) # reset class of var in 1st col to its input class, #168
 

tests/testthat/test-tabyl.R

@@ -395,6 +395,17 @@ test_that("3-way tabyl with 3rd var factor is listed in right order, #250", {
   expect_equal(names(tabyl(z, am, gear, cyl)), c("8", "6", "NA_"))
 })
 
+test_that("tabyl works with label attributes (#394)", {
+  mt_label <- mtcars
+  attr(mt_label$cyl, "label") <- "Number of cyl"
+  tab <- tabyl(mt_label, cyl)
+  expect_named(tab, c("Number of cyl", "n", "percent"))
+  tab2 <- tabyl(mt_label, cyl, am)
+  expect_named(tab2, c("Number of cyl", "0", "1"))
+  tab3 <- tabyl(mt_label, cyl, am, vs)
+  expect_equal(names(tab3[[1]])[1], "Number of cyl")
+})
+
 test_that("tabyl works with ordered 1st variable, #386", {
   mt_ordered <- mtcars
   mt_ordered$cyl <- ordered(mt_ordered$cyl, levels = c("4", "8", "6"))