From 73858d6f6d6747baa7ee1b08654fe4e21370685a Mon Sep 17 00:00:00 2001
From: Andrew Gene Brown <brown.andrewg@gmail.com>
Date: Sat, 18 Nov 2023 12:25:21 -0800
Subject: [PATCH] wbt_file_path: add support for terra objects that have a file
 source for raster and vector inputs  - for #119

---
 NEWS.md              |  2 +-
 R/wbt.R              | 20 +++++++++++++++++++-
 man/wbt_file_path.Rd |  2 +-
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index 555da8d4b..a6ccb2293 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,6 +1,6 @@
 # whitebox 2.3.4
 
- * Exported `wbt_file_path()`, a function previously used internally for creating safe, expanded, quoted, paths for building WhiteboxTools commands. 
+ * Exported `wbt_file_path()`, a function previously used internally for creating safe, expanded, quoted, paths for building WhiteboxTools commands. This function also supports the input of `terra` objects that are backed by file sources supported by WhiteboxTools.
 
 # whitebox 2.3.3
 
diff --git a/R/wbt.R b/R/wbt.R
index 6cf813744..75cac05f6 100644
--- a/R/wbt.R
+++ b/R/wbt.R
@@ -1127,7 +1127,8 @@ wbt_system_call <- function(argstring,
 #' 
 #' @details If an input vector contains `";"` or `","` this is considered, path expansion is performed on the substrings. If the input vector has length greater than `1`, the vector is concatenated with `","` or `";"` to create a single output string. 
 #' 
-#' @param x character. Vector of file paths or strings of file paths for passing as arguments to WhiteboxTools.
+#' @param x character or `terra` object. Vector of file paths or strings of file paths for passing as arguments to WhiteboxTools. If the object is of class `SpatRaster`, `SpatRasterCollection`, `SpatVector` or `SpatVectorProxy` the sources are extracted with `terra::sources()`
+#' 
 #' @param shell_quote logical. Shell quotes around result? Default: `TRUE`
 #' @param delimiter character. Either `","` (default) or `";"` allowed by WhiteboxTools.
 #' @param check_exists logical. Check if file(s) in x exist? Useful for input values. Default: `FALSE`
@@ -1152,6 +1153,23 @@ wbt_system_call <- function(argstring,
 #' wbt_file_path(c("~/abc.tif", "~/def.tif"))
 #' 
 wbt_file_path <- function(x, shell_quote = TRUE, delimiter = ",", check_exists = FALSE) {
+  if (inherits(x, c("RasterLayer", "RasterStack"))) {
+    if (requireNamespace("terra")) {
+      x <- terra::rast(x)
+    }
+  }
+  
+  if (inherits(x, c('SpatRaster','SpatRasterCollection', 
+                    'SpatVector', 'SpatVectorProxy'))) {
+    if (requireNamespace("terra")) {
+      x2 <- paste0(terra::sources(x), collapse = delimiter)
+      if (nchar(x2) == 0) {
+        stop("The supplied 'terra' object for `", as.character(substitute(x)),"` is not backed by a file. Try loading the object directly from the source file with `terra::rast()` or `terra::vect()`. Various raster formats and ESRI Shapefile are supported. See <https://www.whiteboxgeo.com/manual/wbt_book/supported_formats.html> for details.", call. = FALSE)
+      }
+      x <- x2
+    }
+  }
+  
   delimiter <- match.arg(trimws(delimiter), c(",", ";"))
   x <- path.expand(strsplit(
     paste0(as.character(x), collapse = ","), ";|,"
diff --git a/man/wbt_file_path.Rd b/man/wbt_file_path.Rd
index 484188f36..75697dd5e 100644
--- a/man/wbt_file_path.Rd
+++ b/man/wbt_file_path.Rd
@@ -7,7 +7,7 @@
 wbt_file_path(x, shell_quote = TRUE, delimiter = ",", check_exists = FALSE)
 }
 \arguments{
-\item{x}{character. Vector of file paths or strings of file paths for passing as arguments to WhiteboxTools.}
+\item{x}{character or \code{terra} object. Vector of file paths or strings of file paths for passing as arguments to WhiteboxTools. If the object is of class \code{SpatRaster}, \code{SpatRasterCollection}, \code{SpatVector} or \code{SpatVectorProxy} the sources are extracted with \code{terra::sources()}}
 
 \item{shell_quote}{logical. Shell quotes around result? Default: \code{TRUE}}