I think one solution is to create a spreadsheet with the column headers: Event ID, Event Name, Description, Start Time, End Time, Location,Guest List, and then add this script to the spreadsheet. calendarImport() will import all of your calendar events and write them to the sheet. Then, you can modify the event in the spreadsheet line (change location to the Moon), and run calendarCreateEvent to create a new event based on the changes you made. It will automatically send out notifications to all old attendees to accept the new event, as it is a new invitation.
I am pretty close to that solution, but I have a hangup, now, on accessing the calendar to create a new event. I think it's because I'm calling it from an onEdit event function. It's getting late, but if you rewrite the third part of the script to get the events data range, then a for/if loop to check the added versus modified date, then you should be able to create a new event, and delete the old event. This would push a notification of the change in event details to everyone who had accepted the old event already.
I think, given the code example you put up in the beginning, you probably already know how to do that, but if you don't, I could probably throw something together tomorrow night to search for old events that have been recreated and delete them.
Here's my spreadsheet and code in action.
function calendarImport(){
//http://www.google.com/google-d-s/scripts/class_calendar.html#getEvents
// The code below will retrieve events between 2 dates for the user's default calendar and
// display the events the current spreadsheet
var cal = CalendarApp.getDefaultCalendar();
var calId = cal.getId();
var sheet = SpreadsheetApp.getActiveSheet();
var sheetName = SpreadsheetApp.getActiveSheet().setName(calId +" Calendar Data");
var events = cal.getEvents(new Date("March 9, 2014"), new Date("March 14, 2014"));
for (var i=0;i<events.length;i++) {
//http://www.google.com/google-d-s/scripts/class_calendarevent.html
Logger.log(events);
var details=[[events[i].getId(),events[i].getTitle(), events[i].getDescription(), events[i].getStartTime(), events[i].getEndTime(),events[i].getLocation()]];
var guestList = events[i].getGuestList();
var guestArray = [];
for (var n in guestList){
var guestEmail = (guestList[n].getEmail());
guestArray.push(guestEmail);
Logger.log(guestArray);
}
var row=i+1;
var range=sheet.getRange(row+1,1,1,6);
range.setValues(details);
var guestRange = sheet.getRange(row+1,7,1,1);
guestRange.setValues([guestArray]);
var dateAdded = Utilities.formatDate(new Date(), "GMT-6","MM/dd/yy HH:mm:ss");
var dateAddedRange = sheet.getRange(row+1,8,1,1);
dateAddedRange.setValue(dateAdded);
}
}
function onEdit(event){
var ss = SpreadsheetApp.getActiveSpreadsheet();
var calId = CalendarApp.getDefaultCalendar().getId();
var sh = ss.getSheetByName(sheetName);
var actSht = event.source.getActiveSheet();
var actRng = event.source.getActiveRange();
var index = actRng.getRowIndex();
Logger.log(index);
var dateCol = actSht.getLastColumn();
var calId
var lastCell = actSht.getRange(index,dateCol);
var date = Utilities.formatDate(new Date(), "GMT-6", "MM/dd/yyyy HH:mm:ss");
lastCell.setValue(date);
var modifiedRow = sh.getRange(index,1,1,ss.getLastColumn()).getValues();
Logger.log(modifiedRow[0][7])
if (modifiedRow[0][7] < modifiedRow[0][8]){
var firstAdded = modifiedRow[0][7];
var dateModified = modifiedRow[0][8];
calendarCreateEvent(index,firstAdded,dateModified,calId);
}
}
function calendarCreateEvent(index,firstAdded,dateModified,calId){
var sheet = SpreadsheetApp.getActiveSheet();
var added = firstAdded;
var modified = dateModified;
var startRow = index; // First row of data to process
var calId = calId;
Logger.log(calId);
Logger.log(startRow);
Logger.log(added);
Logger.log(modified);
if (modified - added > "0"){
var numRows = 1; // Number of rows to process
var dataRange = sheet.getRange(startRow, 1, numRows, 9);
var data = dataRange.getValues();
var cal = CalendarApp.getCalendarById(calId);
for (i in data) {
var row = data[i];
var eventId = row[0]
var title = row[1]; // First column
var desc = row[2]; // Second column
var tstart = row[3];
var tstop = row[4];
var loc = row[5];
var guests = row[6];
//cal.createEvent(title, new Date("March 3, 2010 08:00:00"), new Date("March 3, 2010 09:00:00"), {description:desc,location:loc});
var newEvent = cal.createEvent(title, tstart, tstop, {description:desc,location:loc, guests:guests});//.addGuest(guests);
var newEventId = newEvent.getId();
Logger.log(newEventId);
}
}
}
