How to refresh a sheet's cell value in Google Apps Script

Question

I\'m experimenting with Blockspring which provides a Google Sheets add-on which can, for example, run a function which returns data from a webservice e.g.

=B         


        

Answer 1

Posting a useful snippet, in case you need to force all formulas to recalculate. This is considerably more performant than other examples posted here.

function forceRefreshSheetFormulas(sheetName) {
  var activeSpreadsheet = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = activeSpreadsheet.getSheetByName(sheetName);
  var range = sheet.getDataRange();
  var numCols = range.getNumColumns();
  var numRows = range.getNumRows();
  var rowOffset = range.getRow();
  var colOffset = range.getColumn();

  // Change formulas then change them back to refresh it
  var originalFormulas = range.getFormulas();

  //Loop through each column and each row in the sheet
  //`row` and `col` are relative to the range, not the sheet
  for (row = 0; row < numRows ; row++){
    for(col = 0; col < numCols; col++){
      if (originalFormulas[row][col] != "") {
        range.getCell(row+rowOffset, col+colOffset).setFormula("");
      }
    };
  };
  SpreadsheetApp.flush();
  for (row = 0; row < numRows ; row++){
    for(col = 0; col < numCols; col++){
      if (originalFormulas[row][col] != "") {
        range.getCell(row+rowOffset, col+colOffset).setFormula(originalFormulas[row][col]);
      }
    };
  };
  SpreadsheetApp.flush();
};

There are a few tricks at work: - Setting a cell's formula to "" clears it, so we avoid that. - We need to change the formula, flush, and change it back and flush again.