Ok, so I have a setup where things get tested and the data is sent to a website in a HTML table in a local network. Now I want to export the table data to an already existing Excel file and create a new sheet every run with the use of a button on the site. Ideally in JavaScript or another HTML script language. I have already found many "solutions" where the data is just downloaded but that's not what I want. The only thing I found that goes in the same direction is this thread: how to export html table and append as a sheet in existing excel using javascript or jquery but the lib is no longer maintained and the website is offline thus providing no documentation. Any help would be highly appreciated.
I have used the SheetJS Community Edition library to create a working codepen on your problem.
The code :
Below snippet, please test on codepen because the XLS file download does not work in the snippet frame.
(async() => {
// GET DATA TO APPEND FROM HTML TABLE
var data_to_append = XLSX.utils.table_to_book(document.getElementById("test_table"));
// GET SHEET "Sheet1" FROM DATA TO APPEND
const newSheet = data_to_append.Sheets["Sheet1"];
// GET ORIGINAL XLS FILE
const url = "https://www.lucasroquilly.com/stack_overflow_samples/workbook.xls";
const data = await (await fetch(url)).arrayBuffer();
/* CREATE WORKBOOK FROM ORIGINAL XLS FILE DATA */
const workbook = XLSX.read(data);
// APPEND SHEET TO WORKBOOK UNDER NAME "Appended Sheet"
XLSX.utils.book_append_sheet(workbook, newSheet, "Appended Sheet", true);
//ATTEMPT TO LAUNCH DOWNLOAD OF FILE
XLSX.writeFile(workbook, 'workbook.xls');
})();.tftable {font-size:12px;color:#333333;width:100%;border-width: 1px;border-color: #729ea5;border-collapse: collapse;}
.tftable th {font-size:12px;background-color:#acc8cc;border-width: 1px;padding: 8px;border-style: solid;border-color: #729ea5;text-align:left;}
.tftable tr {background-color:#d4e3e5;}
.tftable td {font-size:12px;border-width: 1px;padding: 8px;border-style: solid;border-color: #729ea5;}
.tftable tr:hover {background-color:#ffffff;}<script src="https://cdn.sheetjs.com/xlsx-0.18.8/package/dist/xlsx.full.min.js"></script>
<table id="test_table" class="tftable" border="1">
<tr><th>Header 1</th><th>Header 2</th><th>Header 3</th><th>Header 4</th><th>Header 5</th></tr>
<tr><td>NEW Row:1 Cell:1</td><td>NEW Row:1 Cell:2</td><td>NEW Row:1 Cell:3</td><td>NEW Row:1 Cell:4</td><td>Row:1 Cell:5</td></tr>
<tr><td>NEW Row:2 Cell:1</td><td>NEW Row:2 Cell:2</td><td>NEW Row:2 Cell:3</td><td>NEW Row:2 Cell:4</td><td>NEW Row:2 Cell:5</td></tr>
</table>