Merge pull request #38 from JulienBlasco/fix-20-mergecol-exist-not

Fix 20 : merge cols don't exist

NEWS.md

@@ -1,11 +1,13 @@
 # tablexlsx (WIP)
 
 * (fix) `toxlsx()` no longer fails when the `object` argument is the result of a computation #18
+* provide meaningful error message if merge cols don't exist #20
 
 # tablexlsx 1.0.0
 
 This release includes :
 
+
 * `add_table()` and `toxlsx()` now accept a `bygroup` argument that splits the table into groups before writing to the sheet #23
 * most arguments to `add_table()` and `toxlsx()` can now be passed as atomic vectors. If the first argument is a single `data.frame`, the behavior is the same as for a lenght-one list. If the first argument is a list of `data.frame`s, those arguments are recycled in order to match the length of the list. This change applies to the arguments `tosheet`, `title`, `footnoteX`, `mergecol`, `bygroup`, `groupname` #19
 * when a list is passed to `toxlsx()`, the `mergecol` argument can now be specified for each data.frame of the list #21

R/add_table.R

@@ -33,7 +33,7 @@ add_table <- function(
     TableFootnote1 = "",
     TableFootnote2 = "",
     TableFootnote3 = "",
-    MergeCol = NULL,
+    MergeCol = character(0),
     ByGroup = character(0),
     GroupName = FALSE,
     asTable = FALSE) {
@@ -55,6 +55,10 @@ add_table <- function(
     stop("asTable cannot be TRUE if ByGroup is defined")
   }
 
+  if (!all(MergeCol %in% colnames(Table))) {
+    stop("All elements of MergeCol must be existing column names of Table")
+  }
+
   # If the sheet does not exist in the Excel file, we create it; otherwise, we invoke it
   if (!(SheetTitle %in% names(WbTitle))) {
     mysheet <- openxlsx::addWorksheet(WbTitle, SheetTitle)
@@ -173,7 +177,7 @@ add_table <- function(
   )
 
   # If mergecol is filled in
-  if(!is.null(MergeCol)) {
+  if(length(MergeCol)>0) {
 
     # loop on each column of mergecol
     for (mycol in MergeCol) {