add error message for class "difftime"

NEWS.md

@@ -1,4 +1,5 @@
 ## rlistings 0.2.9.9008
+ * Added an error message for listings with variables of `difftime` class.
 
 ## rlistings 0.2.9
  * Added `truetype` font support based on new `formatters` api, by @gmbecker.

R/rlistings_methods.R

@@ -15,6 +15,15 @@ dflt_courier <- font_spec("Courier", 9, 1)
 #' @export
 #' @name listing_methods
 print.listing_df <- function(x, widths = NULL, tf_wrap = FALSE, max_width = NULL, fontspec = NULL, col_gap = 3L,  ...) {
+
+  # check classes
+  column_classes <- lapply(x, function(col) sapply(col, class))
+
+  # Check if any of the columns contain an element of class "difftime"
+  if (any(sapply(column_classes, function(col) any(col == "difftime")))) {
+    stop("Error: Listing contains variables of class 'difftime'. Please convert to character or factor.")
+  }
+
   cat(
     toString(
       matrix_form(x, fontspec = fontspec, col_gap = col_gap),

tests/testthat/test-listings.R

@@ -350,3 +350,19 @@ testthat::test_that("split_into_pages_by_var works as expected", {
   )
   testthat::expect_identical(lsting, lsting_id)
 })
+
+testthat::test_that("appropriate error message returned for 'difftime' class", {
+  tmp_data <- ex_adae[1:100, ]
+  class(tmp_data$study_duration_secs) <- "difftime"
+
+  lsting <- as_listing(
+    tmp_data,
+    key_cols = c("USUBJID", "AGE"),
+    disp_cols = "study_duration_secs",
+    main_title = "title",
+    main_footer = "foot"
+  ) %>%
+    split_into_pages_by_var("SEX", page_prefix = "Patient Subset - Sex")
+
+  testthat::expect_error(print(lsting))
+})