Auto close modal dialog - After server code is done, close dialog in Google Spreadsheet

Question

I have a Google Sheet that runs some Apps Script server code to connect to an SQL server. I want to show the message \"loading...\" in the modal dialog while data is being

Answer 1

//show dialog

var output = HtmlService.createHtmlOutput('Please wait...');
  SpreadsheetApp.getUi().showModalDialog(output, 'Saving...');

some code

//close dialog

  var output = HtmlService.createHtmlOutput('');
  SpreadsheetApp.getUi().showModalDialog(output, 'Loading...');

*optional

  ui.alert("Saved Successfully!")