Set datetime time zone if TZID propery present

R/ic_dataframe.R

@@ -19,6 +19,7 @@ ic_dataframe <- function(x) {
 
   if(methods::is(object = x, class2 = "data.frame")) {
     return(x)
+
   }
 
   stopifnot(methods::is(object = x, class2 = "character") | methods::is(object = x, class2 = "list"))
@@ -35,16 +36,27 @@ ic_dataframe <- function(x) {
   x_df <- ic_bind_list(x_list_named)
 
   date_cols <- grepl(pattern = "VALUE=DATE", x = names(x_df))
+  datetime_cols <- names(x_df) %in% grep("^DT[A-Z]+$|CREATED|LAST-MODIFIED", names(x_df), value = TRUE) # include any column starting with DT
+  tzid_cols <- names(x_df) %in% grep(".*TZID=.*", names(x_df), value = TRUE) # find cols with TZID in name
+  timezones <- unlist(regmatches(names(x_df), gregexpr("(?<=TZID=).*", names(x_df), perl = TRUE))) # pull all tzones from col names into vector to apply separately to each column
+                                                                                                   # in case different events have differing tzones although
+                                                                                                   # think most calendar software only uses single tzone
+
   if(any(date_cols)) {
-    x_df[date_cols] <- lapply(x_df[, date_cols], ic_date)
+    x_df[date_cols] <- lapply(x_df[date_cols], ic_date)
   }
-  datetime_cols <- names(x_df) %in% c("DTSTART", "DTEND")
+
   if(any(datetime_cols)) {
-    x_df[datetime_cols] <- lapply(x_df[, datetime_cols], ic_datetime)
+    if (any(tzid_cols)) {
+      x_df[tzid_cols] <-  Map(function(x, y) ic_datetime(x, tzone = y), x_df[tzid_cols], timezones) # apply timezones to tzid_cols
+      x_df[tzid_cols] <- lapply(x_df[tzid_cols], function(x) {attr(x, "tzone") <- ""; x})           # change tzid_cols to local time zone
+      x_df[datetime_cols & !tzid_cols] <- lapply(x_df[datetime_cols & !tzid_cols], ic_datetime)     # set time zone on datetime cols without TZID to local ic_datetime() does this by default
+    } else {
+      x_df[datetime_cols] <- lapply(x_df[datetime_cols], ic_datetime)
+    }
   }
-
-  # names(x_df) <- gsub(pattern = ".VALUE.DATE", replacement = "", names(x_df))
-
+  names(x_df) <- gsub(pattern = ";VALUE=DATE", replacement = "", names(x_df))
+  names(x_df) <- gsub(pattern = ";TZID.*", replacement = "", names(x_df))
   x_df
 }
 

R/ic_date.R

@@ -7,7 +7,7 @@
 #' @examples
 #' ic_datetime("20180809T160000Z")
 #' ic_date("20120103")
-ic_datetime <- function(x) {
+ic_datetime <- function(x, tzone = "") {  # allow pass through of time zone to as.POSIXct
 
   # TODO (LH): regex check x timestamp
   if(any(!is.na(x) & !(x == "NA") & !grepl("^\\d{8}T\\d{6}Z?$", x))) {
@@ -18,13 +18,13 @@ ic_datetime <- function(x) {
 
   plain <- gsub("[TZtz]", "", x)
 
-  # if time string has a trailing "Z" assign to zulu timezone  
+  # if time string has a trailing "Z" assign to zulu timezone
   if (any(grepl("Z$", x))) {
     datetime <- as.POSIXct(plain, tz = "Zulu", format = "%Y%m%d%H%M%S")
-    attr(datetime, "tzone") <- ""  # change tz to "" which defaults to local system timezone; this could be left out if not desired 
+    attr(datetime, "tzone") <- ""  # change tz to "" which defaults to local system timezone; this could be left out if not desired
                                    # but as.POSIXct() uses tz = "" as standard argument and this is what is used below if not zulu time
   } else {
-    datetime <- as.POSIXct(plain, format = "%Y%m%d%H%M%S")
+    datetime <- as.POSIXct(plain, tz = tzone, format = "%Y%m%d%H%M%S")
   }
   datetime
 }

inst/extdata/apple_calendar_test.ics

@@ -0,0 +1,36 @@
+BEGIN:VCALENDAR
+CALSCALE:GREGORIAN
+PRODID:-//Apple Inc.//macOS 13.4.1//EN
+VERSION:2.0
+X-WR-CALNAME:Test
+BEGIN:VTIMEZONE
+TZID:Europe/London
+BEGIN:DAYLIGHT
+DTSTART:19810329T010000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
+TZNAME:BST
+TZOFFSETFROM:+0000
+TZOFFSETTO:+0100
+END:DAYLIGHT
+BEGIN:STANDARD
+DTSTART:19961027T020000
+RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
+TZNAME:GMT
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0000
+END:STANDARD
+END:VTIMEZONE
+BEGIN:VEVENT
+CREATED:20230320T213321Z
+DESCRIPTION:Testing : 00:00\n
+DTEND;TZID=Pacific/Auckland:20230630T160000
+DTSTAMP:20230709T221931Z
+DTSTART;TZID=Pacific/Auckland:20230630T120000
+LAST-MODIFIED:20230320T213321Z
+LOCATION:London
+SEQUENCE:0
+SUMMARY:This is test data
+TRANSP:OPAQUE
+UID:5C15BDCE-C77A-4A67-BBD3-8D5AD233A034
+END:VEVENT
+END:VCALENDAR

tests/testthat/test-ic_datetime.R

@@ -13,3 +13,10 @@ test_that("ic_datetime works for 20180809T160000Z:", {
 test_that("ic_datetime is NA for empty:", {
   expect_output(ic_datetime(""), NA)
 })
+
+test_that("DTSTART & DTEND time zones equal local time zone ''", {
+  f <- system.file("extdata", "apple_calendar_test.ics", package = "calendar") # "Pacific/Auckland" chosen as original time zone as different to testers local time zone
+  ics_df = ic_read(f)
+  expect_equal(attributes(ics_df$DTSTART)$tzone, "")
+  expect_equal(attributes(ics_df$DTEND)$tzone, "")
+})