Empty sheets after using writeFile

Hi,

I’m using the XLSX module to open a XLSX file with empty sheets and fill them.

This is an extract of our code :

var myXlsx  = XLSX.readFile( filePath );

myXlsx.Sheets[ 'existingSheet' ][ 'F3' ] = {"v":"TEST","t":"s","r":"<t>TEST</t>","h":"TEST"};

XLSX.writeFile(
    myXlsx,
    filePath
);

If i execute the same code with an existing XLSX with non empty sheets it works. But when i try to modify an empty cell it does not work!

Thanks in advance for your time

[reviewher]

@andrewdsilva you can actually change the !ref field to include the full range! see https://github.com/SheetJS/js-xlsx/issues/82 for a similar issue.

@sheetjsdev It would be nice to have a helper function that takes a range and a cell and produces a new range that includes the cell.

[SheetJSDev]

We’re thinking of adding something like this to the utilities:

function range_add_cell(range, cell) {
	var rng = XLSX.utils.decode_range(range);
	var c = typeof cell == 'string' ? XLSX.utils.decode_cell(cell) : cell;
	console.log(rng, c);
	if(rng.s.r > c.r) rng.s.r = c.r;
	if(rng.s.c > c.c) rng.s.c = c.c;

	if(rng.e.r < c.r) rng.e.r = c.r;
	if(rng.e.c < c.c) rng.e.c = c.c;
	return XLSX.utils.encode_range(rng);
}

function add_to_sheet(sheet, cell) {
	sheet['!ref'] = range_add_cell(sheet['!ref'], range);
}

For now it is in the wiki: https://github.com/SheetJS/js-xlsx/wiki/General-Utility-Functions#adding-a-cell-to-a-range