should fix https://code.usgs.gov/gfv2/gfv2.0/-/issues/15

workspace/get_data.Rmd

@@ -25,6 +25,18 @@ if(!dir.exists("bin")) {dir.create("bin")}
 data_dir <- "data"
 out_list <- list("data_dir" = data_dir)
 out_file <- file.path("cache", "data_paths.json")
+
+sevenz <- "7z"
+check_7z <- try(nhdplusTools:::check7z(), silent = TRUE)
+if(is(check_7z, "try-error")) {
+  message("trying to download 7z -- it's not on your path")
+  # Download command-line Z-zip
+  if(!file.exists("bin/7za.exe")){
+    download.file("https://www.7-zip.org/a/7za920.zip", destfile = "bin/7za920.zip")
+    unzip("bin/7za920.zip", exdir = "bin")
+  }
+  sevenz <- "bin/7za.exe"
+}
 ```
 
 ```{r HUC12 outlets}
@@ -88,13 +100,7 @@ if(!file.exists(TE_points_path)) {
   sbtools::item_file_download("5dbc53d4e4b06957974eddae", names = TEz, 
                               destinations = file.path(TE_points_path, TEz))
   
-  # Download command-line Z-zip
-  if(!file.exists("bin/7za.exe")){
-    download.file("https://www.7-zip.org/a/7za920.zip", destfile = "bin/7za920.zip")
-    unzip("bin/7za920.zip", exdir = "bin")
-  }
-  
-  system(paste0("bin/7za.exe e -o", TE_points_path, " ", file.path(TE_points_path, TEz)))
+  system(paste0(sevenz, " e -o", TE_points_path, " ", file.path(TE_points_path, TEz)))
   
   rm(TEz)
 }
@@ -234,20 +240,20 @@ if(!file.exists(nhdplus_dir)) {
   sbtools::item_file_download("5dbc53d4e4b06957974eddae", names = gLz, 
                               destinations = file.path(nhdplus_dir, gLz))
   
-  system(paste0("7z e -o", nhdplus_dir, " ", file.path(nhdplus_dir, gLz)))
+  system(paste0(sevenz, " e -o", nhdplus_dir, " ", file.path(nhdplus_dir, gLz)))
   
   xWalk <- "CrosswalkTable_NHDplus_HU12_CSV.7z"
   
   sbtools::item_file_download("5c86a747e4b09388244b3da1", names = xWalk, 
                               destinations = file.path(nhdplus_dir, xWalk))
   
-  system(paste0("7z e -o", nhdplus_dir, " ", file.path(nhdplus_dir, xWalk)))
+  system(paste0(sevenz, nhdplus_dir, " ", file.path(nhdplus_dir, xWalk)))
   
   x <- tryCatch(
     download_nhdplusv2(data_dir),
     # Quiet the download, overwrite existing files
     error =  function(e)
-    {system(paste0("7z x ", file.path(data_dir, "NHDPlusV21_NationalData_Seamless_Geodatabase_Lower48_07.7z")
+    {system(paste0(sevenz, " x ", file.path(data_dir, "NHDPlusV21_NationalData_Seamless_Geodatabase_Lower48_07.7z")
                      , " -o", data_dir), ignore.stdout = T)}
   )