Can the Insufficient permission message in Google sites be changed or customized?

Question

I am using Google Sites, and if a user does not have the right to view a page they get a message that says "You need permission" or "Insufficient permission".

Can this message be edited or customized?

Or even can this unauthorized user be redirected to another page automatically?

Is there a script that might help?

Answer 1

I got this for the second part of the question but still couldn't find an answer for the first part even in Google documentation.
This is a very simple answer but it helped. We just need to get the user ID and compare it to the list of authorized users, if user is in the list then a link is created, if not, a label is created telling the user they need permission.

function doGet() {
  var app = UiApp.createApplication();

  var arr = new Array(4);
  arr[0] = "user_001@company.com";
  arr[1] = "user_002@company.com";
  arr[2] = "user_003@company.com";
  arr[3] = "user_004@company.com";

  for (var i = 0; i < arr.length; i++) {
    if (Session.getActiveUser().getUserLoginId() == arr[i]){
      var label = app.createLabel('User: ' + Session.getActiveUser().getUserLoginId() + ', You have permission :)');//false
      var link = app.createAnchor('Here is your link', 'http://www.umich.edu').setId("link").setVisible(true);//false
      var flag = 1;
      break;
      //#####################
    } else {
      var label = app.createLabel('You need permission :(');//false
      var flag = 0;
    }
  }
      app.add(label);
  if (flag == 1){app.add(link);}

  return app;
}