How to add multiple comments to excel workbook using openxlsx?

Question

The createComment openxlsx function description states that the comment can be a "Character vector" and hence applied to multiple cells.

However, adding a comment seems to be limited to one cell.

Is there a way to add multiple comments to a range of cells using a character vector?

Have I missed something or is this an enhancement request?

This MWE fails with the following message: "Error in comment_list[[i]]$style[[j]]: subscript out of bounds"

library(openxlsx)

x <- as.data.frame(matrix(1:12, nrow = 3))
names(x) <- letters[1:4]

comment_vector <- paste("Comment", 1:4)

wb <- createWorkbook()
addWorksheet(wb, 1)

header_comments <- createComment(comment = comment_vector)
writeComment(wb, 1, col = 1:4, row = 1, comment = header_comments)

writeData(wb, sheet = 1, startRow = 1, x)

saveWorkbook(wb, "muliple_comments.xlsx", overwrite = TRUE)

This works, but there must be a better way...

header1_comment <- createComment(comment = comment_vector[1])
writeComment(wb, 1, col = 1, row = 1, comment = header1_comment)

header2_comment <- createComment(comment = comment_vector[2])
writeComment(wb, 1, col = 2, row = 1, comment = header2_comment)

header3_comment <- createComment(comment = comment_vector[3])
writeComment(wb, 1, col = 3, row = 1, comment = header3_comment)

header4_comment <- createComment(comment = comment_vector[4])
writeComment(wb, 1, col = 4, row = 1, comment = header4_comment)

writeData(wb, sheet = 1, startRow = 1, x)

saveWorkbook(wb, "05_muliple_comments.xlsx", overwrite = TRUE)

To produce:

Answer 1

I don't think createComment allows comments in multiple cells, the character vector component is there to apply multiple styles as per the example in ?createComment .

Probably the easiest way to get around this is to use lapply or for loop.

lapply(1:4, FUN = function(x) writeComment(wb, 1, col = x, row = 1, comment = createComment(comment = comment_vector[x])))

So in your example provided it will be something like:

library(openxlsx)

x <- as.data.frame(matrix(1:12, nrow = 3))
names(x) <- letters[1:4]
comment_vector <- paste("Comment", 1:4)

wb <- createWorkbook()
addWorksheet(wb, 1)

# Add multiple comments
lapply(1:4, FUN = function(x) writeComment(wb, 1, col = x, row = 1, comment = createComment(comment = comment_vector[x])))

writeData(wb, sheet = 1, startRow = 1, x)
saveWorkbook(wb, "muliple_comments.xlsx", overwrite = TRUE)