Is it possible to fire an event on active sheet change?

Question

Is there an event that fires when the active sheet changes in Google Sheets? Every time the result of getActiveSheet() changes, I would like to call a function

Answer 1

To execute a code when switching between different sheets you can use onSelectionChange(e). For example, the following is a general code template to execute a code when switching to Sheet1:

  function onSelectionChange(e) {
      
    const as = e.source.getActiveSheet();
      if (as.getName() == 'Sheet1'){ 
        // put your code here
      }
    }

In this way, every time you select a different sheet, the onSelectionChange(e) fires and the active sheet changes. Then you can use the active sheet within an if condition to execute a code block of your choice.