add option to not delete past events (#317)

* add option to not delete past events #117

* Remove unnessacary variable passed to processEventCleanup

* Fix date comparison

* add check of start.date

* Make ln 644 easier to understand

Author: non-bin

Code.gs

@@ -2,7 +2,7 @@
 *=========================================
 *       INSTALLATION INSTRUCTIONS
 *=========================================
-* 
+*
 * 1) Make a copy:
 *      New Interface: Go to the project overview icon on the left (looks like this: ⓘ), then click the "copy" icon on the top right (looks like two files on top of each other)
 *      Old Interface: Click in the menu "File" > "Make a copy..." and make a copy to your Google Drive
@@ -23,31 +23,32 @@
 
 var sourceCalendars = [                // The ics/ical urls that you want to get events from along with their target calendars (list a new row for each mapping of ICS url to Google Calendar)
                                        // For instance: ["https://p24-calendars.icloud.com/holidays/us_en.ics", "US Holidays"]
-                                       // Or with colors following mapping https://developers.google.com/apps-script/reference/calendar/event-color, 
+                                       // Or with colors following mapping https://developers.google.com/apps-script/reference/calendar/event-color,
                                        // for instance: ["https://p24-calendars.icloud.com/holidays/us_en.ics", "US Holidays", "11"]
   ["icsUrl1", "targetCalendar1"],
   ["icsUrl2", "targetCalendar2"],
   ["icsUrl3", "targetCalendar1"]
-  
+
 ];
 
-var howFrequent = 15;                  // What interval (minutes) to run this script on to check for new events
-var onlyFutureEvents = false;          // If you turn this to "true", past events will not be synced (this will also removed past events from the target calendar if removeEventsFromCalendar is true)
-var addEventsToCalendar = true;        // If you turn this to "false", you can check the log (View > Logs) to make sure your events are being read correctly before turning this on
-var modifyExistingEvents = true;       // If you turn this to "false", any event in the feed that was modified after being added to the calendar will not update
-var removeEventsFromCalendar = true;   // If you turn this to "true", any event created by the script that is not found in the feed will be removed.
-var addAlerts = "yes";                 // Whether to add the ics/ical alerts as notifications on the Google Calendar events or revert to the calendar's default reminders ("yes", "no", "default").
-var addOrganizerToTitle = false;       // Whether to prefix the event name with the event organiser for further clarity
-var descriptionAsTitles = false;       // Whether to use the ics/ical descriptions as titles (true) or to use the normal titles as titles (false)
-var addCalToTitle = false;             // Whether to add the source calendar to title
-var addAttendees = false;              // Whether to add the attendee list. If true, duplicate events will be automatically added to the attendees' calendar.
-var defaultAllDayReminder = -1;        // Default reminder for all day events in minutes before the day of the event (-1 = no reminder, the value has to be between 0 and 40320)
-                                       // See https://github.com/derekantrican/GAS-ICS-Sync/issues/75 for why this is neccessary.
-var overrideVisibility = "";           // Changes the visibility of the event ("default", "public", "private", "confidential"). Anything else will revert to the class value of the ICAL event.
+var howFrequent = 15;                     // What interval (minutes) to run this script on to check for new events
+var onlyFutureEvents = false;             // If you turn this to "true", past events will not be synced (this will also removed past events from the target calendar if removeEventsFromCalendar is true)
+var addEventsToCalendar = true;           // If you turn this to "false", you can check the log (View > Logs) to make sure your events are being read correctly before turning this on
+var modifyExistingEvents = true;          // If you turn this to "false", any event in the feed that was modified after being added to the calendar will not update
+var removeEventsFromCalendar = true;      // If you turn this to "true", any event created by the script that is not found in the feed will be removed.
+var removePastEventsFromCalendar = true;  // If you turn this to "false", any event that is in the past will not be removed.
+var addAlerts = "yes";                    // Whether to add the ics/ical alerts as notifications on the Google Calendar events or revert to the calendar's default reminders ("yes", "no", "default").
+var addOrganizerToTitle = false;          // Whether to prefix the event name with the event organiser for further clarity
+var descriptionAsTitles = false;          // Whether to use the ics/ical descriptions as titles (true) or to use the normal titles as titles (false)
+var addCalToTitle = false;                // Whether to add the source calendar to title
+var addAttendees = false;                 // Whether to add the attendee list. If true, duplicate events will be automatically added to the attendees' calendar.
+var defaultAllDayReminder = -1;           // Default reminder for all day events in minutes before the day of the event (-1 = no reminder, the value has to be between 0 and 40320)
+                                          // See https://github.com/derekantrican/GAS-ICS-Sync/issues/75 for why this is neccessary.
+var overrideVisibility = "";              // Changes the visibility of the event ("default", "public", "private", "confidential"). Anything else will revert to the class value of the ICAL event.
 var addTasks = false;
 
-var emailSummary = false;              // Will email you when an event is added/modified/removed to your calendar
-var email = "";                        // OPTIONAL: If "emailSummary" is set to true or you want to receive update notifications, you will need to provide your email address
+var emailSummary = false;                 // Will email you when an event is added/modified/removed to your calendar
+var email = "";                           // OPTIONAL: If "emailSummary" is set to true or you want to receive update notifications, you will need to provide your email address
 
 /*
 *=========================================
@@ -103,7 +104,7 @@ function install(){
   //Schedule sync routine to explicitly repeat and schedule the initial sync
   ScriptApp.newTrigger("startSync").timeBased().everyMinutes(getValidTriggerFrequency(howFrequent)).create();
   ScriptApp.newTrigger("startSync").timeBased().after(1000).create();
-  
+
   //Schedule sync routine to look for update once per day
   ScriptApp.newTrigger("checkForUpdate").timeBased().everyDays(1).create();
 }
@@ -133,15 +134,15 @@ function startSync(){
     Logger.log("Another iteration is currently running! Exiting...");
     return;
   }
-  
+
   PropertiesService.getUserProperties().setProperty('LastRun', new Date().getTime());
-  
+
   if (onlyFutureEvents)
     startUpdateTime = new ICAL.Time.fromJSDate(new Date());
-  
-  //Disable email notification if no mail adress is provided 
+
+  //Disable email notification if no mail adress is provided
   emailSummary = emailSummary && email != "";
-  
+
   sourceCalendars = condenseCalendarMap(sourceCalendars);
   for (var calendar of sourceCalendars){
     //------------------------ Reset globals ------------------------
@@ -158,12 +159,12 @@ function startSync(){
     //------------------------ Fetch URL items ------------------------
     var responses = fetchSourceCalendars(sourceCalendarURLs);
     Logger.log("Syncing " + responses.length + " calendars to " + targetCalendarName);
-    
+
     //------------------------ Get target calendar information------------------------
     var targetCalendar = setupTargetCalendar(targetCalendarName);
     targetCalendarId = targetCalendar.id;
     Logger.log("Working on calendar: " + targetCalendarId);
-    
+
     //------------------------ Parse existing events --------------------------
     if(addEventsToCalendar || modifyExistingEvents || removeEventsFromCalendar){
       var eventList =
@@ -192,22 +193,22 @@ function startSync(){
       vevents = parseResponses(responses, icsEventsIds);
       Logger.log("Parsed " + vevents.length + " events from ical sources");
     }
-    
+
     //------------------------ Process ical events ------------------------
     if (addEventsToCalendar || modifyExistingEvents){
       Logger.log("Processing " + vevents.length + " events");
       var calendarTz =
         callWithBackoff(function(){
           return Calendar.Settings.get("timezone").value;
         }, defaultMaxRetries);
-      
+
       vevents.forEach(function(e){
         processEvent(e, calendarTz);
       });
 
       Logger.log("Done processing events");
     }
-    
+
     //------------------------ Remove old events from calendar ------------------------
     if(removeEventsFromCalendar){
       Logger.log("Checking " + calendarEvents.length + " events for removal");

Helpers.gs

@@ -651,7 +651,15 @@ function processEventCleanup(){
       var currentID = calendarEventsIds[i];
       var feedIndex = icsEventsIds.indexOf(currentID);
 
-      if(feedIndex  == -1 && calendarEvents[i].recurringEventId == null){
+      if(feedIndex  == -1                                             // Event is no longer in source
+        && calendarEvents[i].recurringEventId == null                 // And it's not a recurring event
+        && (                                                          // And one of:
+          removePastEventsFromCalendar                                // We want to remove past events
+          || new Date(calendarEvents[i].start.dateTime) > new Date()  // Or the event is in the future
+          || new Date(calendarEvents[i].start.date) > new Date()      // (2 different ways event start can be stored)
+        )
+      )
+      {
         Logger.log("Deleting old event " + currentID);
         callWithBackoff(function(){
           Calendar.Events.remove(targetCalendarId, calendarEvents[i].id);