Question

I am using the following method to read header names in a table and put in excel. Could anyone let me know how to modify this to support multiple tables with header info and data.
i.e. how to modify to pass table id. “headers” is the id for “th” tag in code.

function write_headers_to_excel() 
{
  str="";
  var myTableHead = document.getElementById('headers');
  var rowCount = myTableHead.rows.length;
  var colCount = myTableHead.getElementsByTagName("tr")[0].getElementsByTagName("th").length; 

  var ExcelApp = new ActiveXObject("Excel.Application");
  var ExcelSheet = new ActiveXObject("Excel.Sheet");
   ExcelSheet.Application.Visible = true;

  for(var i=0; i<rowCount; i++) 
  {   
   for(var j=0; j<colCount; j++) 
   {           
      str= myTableHead.getElementsByTagName("tr")[i].getElementsByTagName("th")   [j].innerHTML;
    ExcelSheet.ActiveSheet.Cells(i+1,j+1).Value = str;
}
 }

Answer 1

Your question is a bit vague, so I’m guessing at what you want. Assuming your current function works as is, you can just take out the hard-coding of the table’s ID and pass it in as a parameter:

function write_headers_to_excel(tableID)  {
   var myTableHead = document.getElementById(tableID);
   // rest of your function as is
}

Then call it once for each table, though that will create a new ExcelSheet for each table.

If the idea is for all of the tables to be added to the same ExcelSheet you can pass an array of table IDs to the function something like the following. I’ve kept the basic structure of your function but moved the variable declarations out of the loops (since that what JavaScript does behind the scenes anyway), deleted your ExcellApp variable since it wasn’t used, and moved the getElementsByTagName call out of the inner loop.

write_headers_to_excel(["headers1","headers3","headers7","etc"]);

function write_headers_to_excel(tableIDs)  {
   var myTableHead,
       rowCount,
       cols,
       t,
       i,
       j,
       rowOffset = 1,
       ExcelSheet = new ActiveXObject("Excel.Sheet");

   ExcelSheet.Application.Visible = true;

   for (t=0; t < tableIDs.length; t++) {
      myTableHead = document.getElementById(tableIDs[t]);
      rowCount = myTableHead.rows.length;

      for(i=0; i<rowCount; i++) {
         cols = myTableHead.rows[i].getElementsByTagName("th");
         for(j=0; j < cols.length; j++) {
            ExcelSheet.ActiveSheet.Cells(i+rowOffset,j+1).Value = cols[j].innerHTML;
         }
      }
      rowOffset += rowCount;
   }
}

(No, I haven’t tested it.)