Alternative fix to #42

DESCRIPTION

@@ -10,8 +10,8 @@ Authors@R: c(
   person("Floris", "Vanderhaeghe", role = c("ctb"), comment = c(ORCID = "0000-0002-6378-6229")))
 Maintainer: Emmanuel Blondel <[email protected]>
 Depends: R (>= 3.3.0), methods
-Imports: R6, httr, jsonlite, xml2, keyring, tools, parallel
-Suggests: testthat
+Imports: R6, httr, jsonlite, xml2, keyring, tools
+Suggests: testthat, parallel
 Description: Provides an Interface to 'Zenodo' (<https://zenodo.org>) REST API, 
   including management of depositions, attribution of DOIs by 'Zenodo' and 
   upload of files.

NAMESPACE

@@ -12,6 +12,5 @@ import(keyring)
 import(methods)
 import(xml2)
 importFrom(R6,R6Class)
-importFrom(parallel,mclapply)
 importFrom(tools,file_path_as_absolute)
 importFrom(tools,md5sum)

R/ZenodoRecord.R

@@ -1196,10 +1196,15 @@ ZenodoRecord <-  R6Class("ZenodoRecord",
           }
           if(!is.null(parallel_handler)){
             if(!is.null(cl)){
+              if (!requireNamespace("parallel", quietly = TRUE)) {
+                errMsg <- "Package \"parallel\" needed for cluster-based parallel handler. Please install it."
+                self$ERROR(errMsg)
+                stop(errMsg)
+              }
               if (!quiet) self$INFO("Using cluster-based parallel handler (cluster 'cl' argument specified)")
               if (!quiet) self$INFO(files_summary)
               invisible(parallel_handler(cl, self$files, download_file, ...))
-              try(stopCluster(cl))
+              try(parallel::stopCluster(cl))
             }else{
               if (!quiet) self$INFO("Using non cluster-based (no cluster 'cl' argument specified)")
               if (!quiet) self$INFO(files_summary)

R/zen4R.R

@@ -11,7 +11,6 @@
 #' @import keyring
 #' @importFrom tools file_path_as_absolute
 #' @importFrom tools md5sum
-#' @importFrom parallel mclapply
 #' 
 #' @title Interface to 'Zenodo' REST API
 #' @description Provides an Interface to 'Zenodo' (<https://zenodo.org>) REST API, 

R/zen4R_downloader.R

@@ -9,6 +9,7 @@
 #'  #simple download (sequential)   
 #'  download_zenodo("10.5281/zenodo.2547036")
 #'  
+#'  library(parallel)
 #'  #download files as parallel using a cluster approach (for both Unix/Win systems)
 #'  download_zenodo("10.5281/zenodo.2547036", 
 #'    parallel = TRUE, parallel_handler = parLapply, cl = makeCluster(2))