Feature and Improvement Ideas for openxlsx

[adamborondy]

1. Depending on how easily it could be implemented, it would be useful to set the currency type for the worksheets in some way (e.g. through an option() setting). This way columns with "accounting" or "currency" class could be customised to Euro instead of Dollars for example.
2. (If included in the course) it would be useful to implement insertPlot() in a way that is takes plot objects as input and not the image from the device. Especially, because the current implementation does not work with our Rmd notebooks.
3. addStyle() can be used to customise the body of a spreadsheet (e.g. set borders). However, the cols and rows definition for this step looks quite complicated. Since the first row contains the table header we need to select the body like this:

   addStyle(wb, "sheet1", style = style1, 
            cols = 1:ncol(dataframe), rows = 2:(nrow(dataframe)+1), 
            gridExpand = TRUE)
   

   One could implement some selector functions to customise a specific column/row or the entire body.

Further notes:

4. I think the options("openxlsx.numFmt" = ___) setting mentioned in the vignette does not affect anything.
5. While the vignette applies class(df$Cash) <- "currency", some function documentations apply class(df$Cash) <- c(class(df$Cash), "currency"). This could be made more consistent.

[adamborondy]

In progress:

• new xml parser: [WIP] return file readable for Excel. closes #81 ycphs/openxlsx#134

[adamborondy]

6. Create new excel-native charts
7. xlsb support
8. Implement a way to extract the styling from excel files - and then modify and apply.
9. Is it possible to use loadWorkbook() and then modify a specific worksheet and overwrite it? - Would this be a useful feature?