Add write_xlsx() function (closes #45)

DESCRIPTION

@@ -44,7 +44,8 @@ Imports:
     plyr,
     testthat,
     utils,
-    progress
+    progress,
+    writexl
 Suggests:
     httptest,
     spelling,
@@ -85,5 +86,6 @@ Collate:
     'tests.R'
     'utils-pipe.R'
     'utils.R'
+    'write_xlsx.R'
 VignetteBuilder: knitr
 biocViews: ThirdPartyClient, BiomedicalInformatics, GenomeWideAssociation, SNP

NAMESPACE

@@ -31,6 +31,7 @@ export(union)
 export(variant_to_association)
 export(variant_to_study)
 export(variant_to_trait)
+export(write_xlsx)
 exportClasses(associations)
 exportClasses(studies)
 exportClasses(traits)

R/write_xlsx.R

@@ -0,0 +1,28 @@
+#' Export a GWAS Catalog object to xlsx
+#'
+#' This function exports a GWAS Catalog object to Microsoft Excel xlsx file.
+#' Each table (slot) is saved in its own sheet.
+#'
+#' @param x A \linkS4class{studies}, \linkS4class{associations},
+#'   \linkS4class{variants} or \linkS4class{traits} object.
+#' @param file A file name to write to.
+#'
+#' @return Although this function is run for its side effect of writing an xlsx
+#'   file, the path to the exported file is returned.
+#'
+#' @examples
+#' # Initial setup
+#' .old_wd <- setwd(tempdir())
+#'
+#' # Save an `associations` object, e.g. `associations_ex01`, to xlsx.
+#' write_xlsx(associations_ex01, "associations.xlsx")
+#'
+#' # Cleanup
+#' unlink("associations.xlsx")
+#' setwd(.old_wd)
+#'
+#' @export
+write_xlsx <- function(x, file = stop('`file` must be specified')) {
+  lst <- s4_to_list(x)
+  writexl::write_xlsx(lst, path = file)
+}

inst/WORDLIST

@@ -129,3 +129,6 @@ Magno's
 ABHD
 pkgdown
 precompiled
+fns
+png
+xlsx