write another excel export function

[GregorDeCillia]

It would be nice to get a new excel export function that can directly create xlsx files such as

st <- styledTable(JohnsonJohnson)
new_write_excel(st, "file.xlsx")

The current function write_excel writes into a sheet object by reference, which is more flexible, but also harder to use.

Namespace implications

We should consider renaming write_excel. My suggestion:

write_excel(st, "file.xlsx")         # <- new function
write_excel_sheet(st, sheet_obj)     # <- formerly write_excel

If we don't want to introduce breaking changes, we could also use

write_xlsx(st, "file.xlsx")          # <- new function
write_excel(st, sheet_obj)           # <- leave unchanged

The reason why I prefer the first option is, that this way write_excel is consistent with write_pdf, write_png and so on in the sense that a file is produced.

[GregorDeCillia]

The body of the new function can be as simple as these lines from the getting started vignette

styledTables/vignettes/styledTables.Rmd

Lines 120 to 130 in 5d38b6b

	library(xlsx)
	# open new xlsx workbook and create a worksheet
	wb <- createWorkbook()
	sheet <- createSheet(wb, "iris_table")
	# insert the styled table in the worksheet
	write_excel(sheet, st2)
	# save the workbook
	saveWorkbook(wb, "test.xlsx")

altough I would suggest to support most or all parameters from xlsx::write.xlsx to get consistency with this wiedly known function.

[GregorDeCillia]

Updates after talking to @a-maldet

• we should also consider the parameters in openxlsx::write.xlsx when deciding about the parameter names of the new function
• the new function will be called write_xlsx for consistency
• braking changes are OK, if they increase the usability
• The current version of write_excel will be removed from the namespace altogether since there are too many "under the hood" things happening