major overhaul with new functions. docs are lacking

R/shiny_cast.R

@@ -34,3 +34,57 @@ shiny_cast <- function() {
   )
 }
 
+
+#' Helper to import files correctly
+#'
+#' @param filenames file names
+#'
+#' @return character vector
+#' @export
+#'
+#' @examples
+#' file_extension(list.files(here::here(""))[[2]])[[1]]
+#' file_extension(c("file.cd..ks","file"))
+file_extension <- function(filenames) {
+  sub(pattern = "^(.*\\.|[^.]+)(?=[^.]*)", replacement = "",
+      filenames,
+      perl = TRUE)
+}
+
+#' Flexible file import based on extension
+#'
+#' @param file file name
+#' @param consider.na character vector of strings to consider as NAs
+#'
+#' @return tibble
+#' @export
+#'
+#' @examples
+#' read_input("https://raw.githubusercontent.com/agdamsbo/cognitive.index.lookup/main/data/sample.csv")
+read_input <- function(file, consider.na = c("NA", '""', "")) {
+  ext <- file_extension(file)
+
+  tryCatch(
+    {
+      if (ext == "csv") {
+        df <- readr::read_csv(file = file, na = consider.na)
+      } else if (ext %in% c("xls", "xlsx")) {
+        df <- openxlsx2::read_xlsx(file = file, na.strings = consider.na)
+      } else if (ext == "dta") {
+        df <- haven::read_dta(file = file)
+      } else if (ext == "ods") {
+        df <- readODS::read_ods(file = file)
+      } else {
+        stop("Input file format has to be on of:
+             '.csv', '.xls', '.xlsx', '.dta' or '.ods'")
+      }
+    },
+    error = function(e) {
+      # return a safeError if a parsing error occurs
+      stop(shiny::safeError(e))
+    }
+  )
+
+  df
+}
+