From 640add3c510cec835a6cbd7b7d1921147675a0ac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20=C5=BB=C3=B3=C5=82tak?= <zozlak@zozlak.org>
Date: Tue, 18 Dec 2018 12:08:54 +0100
Subject: [PATCH] S2_download() can now be interrupted.

---
 .travis.yml     |  1 +
 DESCRIPTION     |  2 +-
 NEWS.md         |  3 ++-
 R/S2_download.R | 51 ++++++++++++++++++++++++++++---------------------
 4 files changed, 33 insertions(+), 24 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index b7d837d..5aac4ba 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,6 +11,7 @@ addons:
   apt:
     packages:
       - libgdal-dev
+      - libudunits2-dev
 
 after_success:
   - Rscript -e 'covr::coveralls(function_exclusions = c("\\.onLoad"))'
diff --git a/DESCRIPTION b/DESCRIPTION
index c447a41..1982a72 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: sentinel2
 Title: Tools to access Sentinel-2 data pre-processed by IVFL, BOKU Vienna
-Version: 0.3.0
+Version: 0.3.1
 Authors@R: c(
     person("Sebastian", "Boeck",  email = "sebastian.boeck@boku.ac.at", role = c("aut", "cre")),
     person("Mateusz",   "Zoltak", email = "mateusz.zoltak@boku.ac.at",  role = c("ctb"))
diff --git a/NEWS.md b/NEWS.md
index 7067f7f..2b42f9b 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,6 @@
-# 0.3.0 (2018-12-18)
+# 0.3.1 (2018-12-18)
 
+* It is now possible to abort the `S2_download()` function.
 * A `spatial` parameter of the `S2_query_granule()` and `S2_query_image()` is now
   a string and allows to choose between the `sp` package and the `sf` package spatial
   object representation.
diff --git a/R/S2_download.R b/R/S2_download.R
index e6f540a..1c6ee8a 100644
--- a/R/S2_download.R
+++ b/R/S2_download.R
@@ -17,7 +17,7 @@
 #' @examples
 #' \dontrun{
 #'   # find, download and unzip a full granule
-#'   granules <- S2_query_granule(
+#'   granules = S2_query_granule(
 #'     utm = '33UXP',
 #'     dateMin = '2016-06-01',
 #'     dateMax = '2016-06-30'
@@ -25,7 +25,7 @@
 #'   S2_download(granules$url, granules$date)
 #'
 #'   # find and download a bunch of images
-#'   images <- S2_query_image(
+#'   images = S2_query_image(
 #'     utm = '33UXP',
 #'     dateMin = '2016-06-01',
 #'     dateMax = '2016-06-30',
@@ -43,7 +43,7 @@
 #'   )
 #' }
 
-S2_download <- function(url, destfile, zip = TRUE, skipExisting = TRUE, progressBar = TRUE, ...){
+S2_download = function(url, destfile, zip = TRUE, skipExisting = TRUE, progressBar = TRUE, ...){
   url = as.character(url)
   destfile = as.character(destfile)
   stopifnot(
@@ -54,26 +54,26 @@ S2_download <- function(url, destfile, zip = TRUE, skipExisting = TRUE, progress
     length(url) == length(destfile)
   )
   filter = !is.na(url)
-  url <- url[filter]
-  destfile <- destfile[filter]
+  url = url[filter]
+  destfile = destfile[filter]
   stopifnot(all(!is.na(destfile)))
 
   addParam = list(...)
   if (zip) {
-    addParam[['format']] <- "application/zip"
+    addParam[['format']] = "application/zip"
   }
   if (length(addParam) > 0) {
     stopifnot(
       all(names(addParam) != ''),
       length(unique(names(addParam))) == length(addParam)
     )
-    addParamNames <- sapply(names(addParam), utils::URLencode)
-    addParamValues <- sapply(as.character(addParam), utils::URLencode)
-    addParam <- paste0(addParamNames, '=', addParamValues, collapse = '&')
-    url <- paste0(url, '?', addParam)
+    addParamNames = sapply(names(addParam), utils::URLencode)
+    addParamValues = sapply(as.character(addParam), utils::URLencode)
+    addParam = paste0(addParamNames, '=', addParamValues, collapse = '&')
+    url = paste0(url, '?', addParam)
   }
 
-  success <- rep(FALSE, length(url))
+  success = rep(FALSE, length(url))
   if (progressBar) {
     pb = txtProgressBar(0, length(url), style = 3)
   }
@@ -86,19 +86,26 @@ S2_download <- function(url, destfile, zip = TRUE, skipExisting = TRUE, progress
       setTxtProgressBar(pb, i)
     }
 
-    try({
-      curl::curl_download(url = url[i], destfile = destfile[i], quiet = TRUE)
+    tryCatch(
+      {
+        curl::curl_download(url = url[i], destfile = destfile[i], quiet = TRUE)
 
-      signature = readBin(destfile[i], 'raw', 4)
-      if (all(signature == as.raw(c(80L, 75L, 3L, 4L))) & zip) {
-        destfile[i] = sub('[.]zip$', '', destfile[i])
-        zipfile = paste0(destfile[i], '.zip')
-        file.rename(destfile[i], zipfile)
-        utils::unzip(zipfile = zipfile, exdir = destfile[i])
-      }
+        signature = readBin(destfile[i], 'raw', 4)
+        if (all(signature == as.raw(c(80L, 75L, 3L, 4L))) & zip) {
+          destfile[i] = sub('[.]zip$', '', destfile[i])
+          zipfile = paste0(destfile[i], '.zip')
+          file.rename(destfile[i], zipfile)
+          utils::unzip(zipfile = zipfile, exdir = destfile[i])
+        }
 
-      success[i] = TRUE
-    })
+        success[i] = TRUE
+      },
+      warning = function(w) {
+        if (all(w$message == 'Operation was aborted by an application callback')) {
+          break
+        }
+      }
+    )
   }
 
   return(invisible(success))