Merge pull request #161 from ropensci/query

expose and store properly query time. Closes #160

NEWS.md

@@ -1,6 +1,7 @@
 # tidyhydat 0.5.3.9000
 - When add a local timezone column, use the most common timezone in the data rather than the first one. This just seems more likely to be useful to users
 - Add more documentation to `realtime_add_local_datetime` to make how timezones are dealt with clearer (#157)
+- Expose the query time for realtime functions as an attribute (#160)
 
 # tidyhydat 0.5.3
 - Allow pkg to loaded without internet and rather just issue an message when it is not. (#149)

R/realtime-classes.R

@@ -13,12 +13,16 @@
 ## Add "realtime" class
 as.realtime <- function(x) {
   class(x) <- c("realtime", setdiff(class(x), "realtime"))
+  t <- Sys.time()
+  attr(t, "tzone") <- "UTC"
+  attr(x, "query_time") <- t
+
   x
 }
 
 #' @export
 print.realtime <- function(x, ...){
-  cat(paste("  Queried on:", format(Sys.time(), tz = "UTC"), "(UTC)\n"))
+  cat(paste("  Queried on:", attributes(x)$query_time, "(UTC)\n"))
   if(c("Date") %in% names(x) && !all(is.na(x$Date))){
     date_range = paste0(range(as.Date(x$Date), na.rm = TRUE), collapse = " to ")
     cat(paste0("  Date range: ", date_range, " \n"))

R/realtime.R

@@ -20,7 +20,8 @@
 #'
 #' @inheritParams hy_stations
 #'
-#' @return A tibble of water flow and level values. 
+#' @return A tibble of water flow and level values. The date and time of the query (in UTC) is also 
+#' stored as an attribute.
 #' 
 #' @format A tibble with 8 variables:
 #' \describe{
@@ -41,8 +42,11 @@
 #' ## Download from multiple provinces
 #' realtime_dd(station_number=c("01CD005","08MF005"))
 #'
-#' # To download all stations in Prince Edward Island:
-#' realtime_dd(prov_terr_state_loc = "PE")
+#' ## To download all stations in Prince Edward Island:
+#' pei <- realtime_dd(prov_terr_state_loc = "PE")
+#' 
+#' ## Access the time of query
+#' attributes(pei)$query_time
 #' }
 #' 
 #' @family realtime functions

tests/testthat/test_download_realtime.R

@@ -9,14 +9,15 @@ context("Testing realtime functions")
   )
 })
 
-test_that("realtime_dd can download stations from a whole province using prov_terr_state_loc", {
+test_that("realtime_dd can download stations from a whole province using prov_terr_state_loc and stores query time", {
   #skip_on_travis()
   skip_on_cran()
   expected_columns <- c("STATION_NUMBER", "PROV_TERR_STATE_LOC", "Date", "Parameter", 
                         "Value", "Grade", "Symbol", "Code")
   rldf <- realtime_dd(prov_terr_state_loc = "PE")
 
   expect_true(identical(expected_columns,colnames(rldf)))
+  expect_is(attributes(rldf)$query_time, "POSIXct")
 })