Is there a faster way to refresh all of my custom formulas?

Question

I need to refresh all of my custom formulas via a script in Google Sheets but this seems to take forever (like, 30 seconds for 100 cells). There will potentially be thousands of cells with my custom formula so I must come up with a better way. I have:

function refresher(){
  var sheet = SpreadsheetApp.getActiveSheet();
  var selection = sheet.getDataRange();
  var columns = selection.getNumColumns();
  var rows = selection.getNumRows();
  for (var column=1; column <= columns; column++){
    for (var row=1; row <= rows; row++){
      var cell=selection.getCell(row,column);
      var formula = cell.getFormula();
      if (formula.startsWith("=myfunc(")){
        cell.setFormula(formula.replace("=myfunc(", "?myfunc("));
      }
    }
  }
  SpreadsheetApp.flush();
  for (var column=1; column <= columns; column++){
    for (var row=1; row <= rows; row++){
      var cell=selection.getCell(row,column);
      var formula = cell.getFormula();
      if (formula.startsWith("=?myfunc(")){
        cell.setFormula(formula.replace("=?myfunc(", "=myfunc("));
      }
    }
  }
}

Answer 1

In order to achieve your goal, how about using TextFinder? In this case, I think that the process cost might be able to be reduced. From your script, when TextFinder is used for your situation, it becomes as follows.

Sample script:

function refresher() {
  const sheet = SpreadsheetApp.getActiveSheet();
  const formula = "=myfunc";
  const tempFormula = "=sampleFormula";
  sheet.createTextFinder("^\\" + formula).matchFormulaText(true).useRegularExpression(true).replaceAllWith(tempFormula);
  sheet.createTextFinder("^\\" + tempFormula).matchFormulaText(true).useRegularExpression(true).replaceAllWith(formula);
}

Reference:

• Class TextFinder