Add argument "crs" to read_asc_[gz_]file()

and remove argument "projection" from read_asc_file()

R/get_example_grid_germany.R

@@ -8,6 +8,15 @@
 #'  * [get_shapes_of_germany].
 get_example_grid_germany <- function()
 {
+  #kwb.utils::assignPackageObjects("kwb.dwd")
+
   path <- "evapo_p/grids_germany_monthly_evapo_p_202201.asc.gz"
-  read_asc_gz_file(url = ftp_path_grids_germany("monthly", path))
+  url <- ftp_path_grids_germany("monthly", path)
+
+  #epsg <- get_epsg_from_url(url)
+  epsg <- 31467L
+
+  crs <- sf::st_crs(epsg)
+
+  read_asc_gz_file(url = url, crs = crs)
 }

R/read_asc_gz_file.R

@@ -11,7 +11,11 @@
 #' @seealso
 #'  * [read_binary_radolan_file],
 #'  * [unzip_asc_gz_file].
-read_asc_gz_file <- function(file, url = NULL)
+read_asc_gz_file <- function(
+    file,
+    url = NULL,
+    crs = if (!is.null(url)) get_epsg_from_url(url)
+)
 {
   target_dir <- if (is.null(url)) {
     dirname(file)
@@ -26,39 +30,32 @@ read_asc_gz_file <- function(file, url = NULL)
   )
 
   #dir(target_dir)
+  #kwb.utils::hsOpenWindowsExplorer(dirname(grid_file))
 
   # Read the .asc file into a raster object (with appropriate projection)
-  read_asc_file(grid_file)
+  read_asc_file(file = grid_file, crs = crs)
 }
 
 # read_asc_file ----------------------------------------------------------------
 
 #' Read Raster Data from .ASC File
 #'
 #' @param file path to .asc file
-#' @param projection projection string used in Radolan data. Currently not used!
+#' @param crs coordinate reference system to be applied to the data. An object
+#'   of class "crs" (as returned by \code{\link[sf]{st_crs}} is expected here.
 #' @param dbg logical indicating whether to show debug messages
 #' @importFrom kwb.utils catAndRun
 #' @importFrom raster `crs<-` raster
-read_asc_file <- function(
-    file,
-    projection = get_radolan_projection_string(),
-    dbg = TRUE
-)
+read_asc_file <- function(file, crs = NULL, dbg = TRUE)
 {
   kwb.utils::catAndRun(
     sprintf("Reading %s using raster::raster()", basename(file)),
     dbg = dbg,
     expr = {
 
       # Provide a copy of the projection file in the same folder
-      provide_projection_file(file)
-      result <- raster::raster(file)
-
-      #result <- raster::raster(file, values = TRUE)
-      #raster::crs(result) <- projection
-
-      result
+      #prj_file <- provide_projection_file(file)
+      raster::raster(file, native = TRUE, crs = crs)
     }
   )
 }

tests/testthat/test-function-get_epsg_from_url.R

@@ -12,7 +12,7 @@ test_that("get_epsg_from_url() works", {
   url_2 <- paste0(start_url, "precipitation/01_Jan/grids_germany_monthly_precipitation_188101.asc.gz")
   url_3 <- kwb.dwd:::get_radolan_url("hourly", year_month = "202001")
 
-  expect_error(f(url_1))
+  capture.output(expect_error(f(url_1)))
   expect_identical(f(url_2), 31467L)
   expect_identical(f(url_3), 3034L)
 })

tests/testthat/test-function-read_asc_file.R

@@ -6,5 +6,4 @@ test_that("read_asc_file() works", {
 
   expect_error(f())
   expect_error(expect_warning(f("no-such-file", dbg = FALSE)))
-
 })

tests/testthat/test-function-read_asc_gz_file.R

@@ -1,17 +1,23 @@
-#
-# This test file has been generated by kwb.test::create_test_files()
-# launched by user hsonne on 2022-09-16 16:43:24.
-# Your are strongly encouraged to modify the dummy functions
-# so that real cases are tested. You should then delete this comment.
-#
+#library(testthat)
 
 test_that("read_asc_gz_file() works", {
 
   f <- kwb.dwd:::read_asc_gz_file
 
-  expect_error(
-    kwb.dwd:::read_asc_gz_file()
-    # argument "file" is missing, with no default
-  )
+  expect_error(f())
 
+  start_url <- "ftp://opendata.dwd.de/climate_environment/CDC/grids_germany/monthly/"
+
+  #head(grep("\\.asc.gz$", kwb.dwd::dwd_files$file, value = TRUE))
+
+  url_1 <- paste0(start_url, "evapo_p/grids_germany_monthly_evapo_p_202201.asc.gz")
+  url_2 <- paste0(start_url, "precipitation/01_Jan/grids_germany_monthly_precipitation_188101.asc.gz")
+
+  crs <- sf::st_crs(31467L)
+
+  expect_output(result_1 <- f(url = url_1, crs = crs))
+  expect_output(result_2 <- f(url = url_2, crs = crs))
+
+  expect_s4_class(result_1, "RasterLayer")
+  expect_s4_class(result_2, "RasterLayer")
 })