Updating Google Calendars from a Google Spreadsheet

I got a request today along the lines of:

We’re in the process of creating a master calendar of events spreadsheet relevant to [various things]. These [various things] will all then have their own Google calendar so they can be looked at individually, embedded etc and everyone could of course have access to all and view them all via their personal Google calendar, turn different calendars on or off, sync with Outlook etc. etc.

X said “wouldn’t it be great if we made the master spreadsheet with Google docs and it could somehow automate and complete the calendars”.

Sigh…;-) So – is it possible?

I’ve only had a quick play so far with Google Apps script, but yes, it seems to be possible…

Take one spreadsheet, liberally sprinkled with event name, description, start and end times, an optional location, and maybe a even a tag or too (not shown):

The time related columns I specified as a date type using the “Data Validation…” form from the Tools menu:

Now take one Google apps script:

function caltest1() {
  var sheet = SpreadsheetApp.getActiveSheet();
  var startRow = 2;  // First row of data to process
  var numRows = 2;   // Number of rows to process
  var dataRange = sheet.getRange(startRow, 1, numRows, 5);
  var data = dataRange.getValues();
  var cal = CalendarApp.getDefaultCalendar();
  for (i in data) {
    var row = data[i];
    var title = row[0];  // First column
    var desc = row[1];       // Second column
    var tstart = row[2];
    var tstop = row[3];
    var loc = row[4];
    //cal.createEvent(title, new Date("March 3, 2010 08:00:00"), new Date("March 3, 2010 09:00:00"), {description:desc,location:loc});
    cal.createEvent(title, tstart, tstop, {description:desc,location:loc});

(This was largely a copy and paste from Sending emails from a Spreadsheet Tutorial, which I’d half skimmed a week or two ago and seemed to remember contained a howto for bulk mailing from a spreadsheet, and the Apps script Calendar class documentation.)

And here’s the result of running the function:

The email tutorial adds a bit of gloss that allows a further column to contain state information about whether an email has already been set; we could do something similar to specify whether or not an event has been automatically added to the calendar, and if not, add it when the function is run.

Because it can be a pain having to go into the script editor to run the function, it’s easier to just create a menu option for it:

Here’s how:

function onOpen() {
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var menuEntries = [ {name: "Shove stuff in calendar", functionName: "caltest2"} ];
  ss.addMenu("OUseful", menuEntries);

I had a little play to see if I could trivially get an RSS feed into the spreadsheet using an =importFeed() formula, and use the details from that to populate the calendar, but for some reason the feed importer function didn’t appear to be working?:-( When I tried using CSV data from a Yahoo RSS2CSV proxy pipe via a =importData() formula, the test function I’d written didn’t appear to recognise the date format…

PS Arghh… the test formula assumes a Date type is being passed to it… Doh!

Hack round importFeed still not working by grabbing a CSV version of the feed into the spreadsheet:

Tweak the calendar event creation formula:

cal.createEvent(title, new Date(tstart), new Date(tstop), {description:desc});

Run the function:

Heh heh :-)

PS it’s also possible to move content from a Google Calendar to a Google spreadsheet, as Grabbing Google Calendar Event Details into a Spreadsheet shows…

PPS it strikes me that the spreadsheets2calendar route provides one way of generating an iCal feed from a list of event times held in a spreadsheet, by popping the events into a Calendar and then making the most of its output formats? A bit like using Yahoo pipes as a quick’n’easy KML generator?

[UPDATE: related, via @mhawksey – Using Google Apps Script for a event booking system (Spreadsheet to Calendar & Site | Form to Spreadsheet, Email and possible Contacts)]

Re: not creating duplicate entries, check out this thread

Grabbing Google Calendar Event Details into a Spreadsheet

A comment to Updating Google Calendars from a Google Spreadsheet, where I showed how to get events described in a Google spreadsheet into a Google Calendar wondered if the other way around is possible? … It would be great for logging hours for projects or declaring working hours ;-)

Yes:-) Twenty seconds ago, this spreadsheet was empty:

A quick run of a script and I populated it from my default calendar using Google Apps script. Once again, all I did was peek through the docs and pull out the fragments I needed: Here’s the script:

function caltest3(){
  // 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 sheet = SpreadsheetApp.getActiveSheet();
  var events = cal.getEvents(new Date("March 8, 2010"), new Date("March 14, 2010"));
  for (var i=0;i<events.length;i++) {
    var details=[[events[i].getTitle(), events[i].getDescription(), events[i].getStartTime(), events[i].getEndTime()]];
    var row=i+1;
    var range=sheet.getRange(row,1,1,4);

So now not only can we use a spreadsheet as a database we can also use a calendar in a similar way, and if necessary, link them all together?

Maintaining a Google Calendar from a Google Spreadsheet, Reprise

In the post Updating Google Calendars from a Google Spreadsheet, I described a recipe for adding events to a Google Calendar from a Google Spreadsheet using Google Apps Script. After a quick chat with the person who was compiling a spreadsheet they wanted to use to populate a set of calendars, I revisited the script to make a few tweaks and hopefully increase its usability.

So here’s a glimpse of the spreadsheet they’re using to list dates for various campaigns and channels where related activity might occur. Firstly, we have some columns relating to the event or activity, and the dates on which they occur. The first column (added to calendar) is a control switch that identifies that the calendar details have been updated for that event:

Within the spreadsheet, I set the two date columns to have the Date type (from the Tools menu, set the Data Validation option to Date). I’m not sure how the spreadsheet is (correctly) identifying the US date format (MM-DD-YY) – maybe from a US timezone as a global setting for the spreadsheet?

As well as various other admin columns, there are columns relating to whether or not a channel will be used to support a particular event:

From what I could ascertain, the way the spreadsheet is supposed to work goes along the lines of: someone adds details of an event and the associated channels for the event to the spreadsheet. “Add” in a channel column says that event is to be added to that channel calendar. When the updating script is run, for each event it checks the control column A to see that an event hasn’t been added to the various channel calendars, and if it hasn’t checks the channel columns; if a channel column is set to “Add” the event details are added to that event calendar.

So – how do I need to modify the original script? Firstly, the original script use the default calendar. In this case, we need a separate calendar for each channel, so in Google Apps I created one calender per channel:

We can grab a calendar by name from a spreadsheet apps script using a call of the form:

 var cal_broadcast=CalendarApp.openByName("broadcastDemo");

When the script runs, we need to grab the appropriate range of cells from the spreadsheet to see which calendars to update. For testing purposes, I only grabbed a few rows…

var startRow = 2;  // First row of data to process
var numRows = 4   // Number of rows to process
var dataRange = sheet.getRange(startRow, 1, numRows, 26);
var data = dataRange.getValues();

for (i in data) {
  var row = data[i];
  var title = row[1];
  var desc=row[15];
  var added = row[col_added];  //Check to see if details for this event have been added to the calendar(s)
  var tstart = row[2]; //start time - I have defined the column in the spreadsheet as a Date type
  var tstop = row[3]; //start time - I have defined the column in the spreadsheet as a Date type
  var broadcast=row[col_broadcast]; // is this event one to "Add" to the broadcast calendar?
  var itunes=row[col_itunes]; // is this event one to "Add" to the itunes calendar? etc
  var youtube=row[col_youtube];
  if (added!="Added") { //the calendar(s) have not been updated for this event
    if (broadcast=="Add") {
      cal_broadcast.createEvent(title, tstart,tstop, {description:desc}); //add the event to the "broadcast" calendar
    if (itunes=="Add"){
      cal_itunes.createEvent(title, tstart,tstop, {description:desc});
    // etc for each channel
    var v = parseInt(i)+2; // +2 is an offset to do with the numbering of rows and the "blank" header row 0;
    sheet.getRange(v, 1, 1, 1).setValue("Added"); //set the fact that we have updated the calendars for this event

In order to identify which columns to use to identify the broadcast, itunes, etc channels, I went defensive (the following bit of code comes before the previous snippet; what is does is to look at each column heading, and then set the column number for each channel appropriately based on its name; I should probably use a similar technique to identify the start/stop dates. What this approach does is accommodate changes to the spreadsheet in terms of the insertion of additional columns or the reordering of columns, for example, at a later date):

var ss=SpreadsheetApp.getActiveSpreadsheet();
var sheet=SpreadsheetApp.setActiveSheet(ss.getSheets()[0]); //need a routine to set active sheet by name?
//go defensive
var col_broadcast,col_itunes, col_youtube=1;
var maxcols=sheet.getMaxColumns();
for (var j=1;j<=maxcols;j++){
  var header= sheet.getRange(1, j, 1, 1).getValue();
   case "Added to Google (Y/N/Hold)":col_added=j-1;
   case "Broadcast":col_broadcast=j-1; break;
   case "iTunes":col_itunes=j-1; break;
   case "YouTube": col_youtube=j-1; break;

Running the combined function thus searches the spreadsheet for the appropriate channel columns and control column, checks the control column for each event entry to ensure that the event hasn’t been added to the selected calendars, and then adds the event to the appropriate channel calendars if required.

Playing with the script, it seemed a little bit clunky, so I tweaked it to update the channel cells with the word “Added” if it had been set to Add, and the calendar had been updated:

if (broadcast=="Add") {
  cal_broadcast.createEvent(title, tstart,tstop, {description:desc});
  dataRange.getCell(parseInt(i)+1,col_broadcast+1).setValue('Added'); // Replace "Add" with "Added"; +1 is offset for sheet numbering

It also struck me that if the settings of a channel was updated to “Add” after that event was updated, that channel’s calendar would never get updated. So I created a variant of the updating function that would just run on a per column basis and update a calendar entry for an event if it was set to “Add”, rather than checking the control column:

function caltestAddtoCal_broadcast(){ caltestAddtoCal("broadcast"); }
function caltestAddtoCal(addCal){
  if (addCal!="") {
    if ((addCal=="broadcast")&&(broadcast=="Add")) {
      cal_broadcast.createEvent(title, tstart,tstop, {description:desc});
      dataRange.getCell(parseInt(i)+1,col_broadcast+1).setValue('Added'); //+1 is offset for sheet numbering
  // ...

What this means is is that a channel controller can update entries in their calendar by running the script just for that channel and adding “Add” to any event they want adding to the calendar, the list of “Added” entries showing which events have already been added to that calendar:

Having doodled a script that sort of works, it’s now time to hack it around it so it looks a little more elegant. Which means refactoring.. sigh… and another reprise in a day or two, I guess…?!

Google Spreadsheets API: Listing Individual Spreadsheet Sheets in R

In Using Google Spreadsheets as a Database Source for R, I described a simple Google function for pulling data into R from a Google Visualization/Chart tools API query language query applied to a Google spreadsheet, given the spreadsheet key and worksheet ID. But how do you get a list of sheets in spreadsheet, without opening up the spreadsheet and finding the sheet names or IDs directly? [Update: I’m not sure the query language API call lets you reference a sheet by name…]

The Google Spreadsheets API, that’s how… (see also GData Samples. The documentation appears to be all over the place…)

To look up the sheets associated with a spreadsheet identified by its key value KEY, construct a URL of the form:


This should give you an XML output. To get the output as a JSON feed, append ?alt=json to the end of the URL.

Having constructed the URL for sheets listing for a spreadsheet with a given key identifier, we can pull in and parse either the XML version, or the JSON version, into R and identify all the different sheets contained within the spreadsheet document as a whole.

First, the JSON version. I use the RJSONIO library to handle the feed:

ssURL=paste( sep="", 'http://spreadsheets.google.com/feeds/worksheets/', sskey, '/public/basic?alt=json' )
for (el in spreadsheet$feed$entry) sheets=c(sheets,el$title['$t'])

Using a variant of the function described in the previous post, we can look up the data contained in a sheet by the sheet ID (I’m not sure you can look it up by name….?) – I’m not convinced that the row number is a reliable indicator of sheet ID, especially if you’ve deleted or reordered sheets. It may be that you do actually need to go to the spreadsheet to look up the sheet number for the gid, which actually defeats a large part of the purpose behind this hack?:-(

gsqAPI = function( key, query,gid=0){ return( read.csv( paste( sep="", 'http://spreadsheets.google.com/tq?', 'tqx=out:csv', '&tq=', curlEscape(query), '&key=', key, '&gid=', curlEscape(gid) ) ) ) }
gsqAPI(sskey,"select * limit 10", 9)

getting a list of sheet names from a goog spreadsheet into R

The second approach is to pull on the XML version of the sheet data feed. (This PDF tutorial got me a certain way along the road: Extracting Data from XML, but then I got confused about what to do next (I still don’t have a good feel for identifying or wrangling with R data structures, though at least I now know how to use the class() function to find out what R things the type of any given item is;-) and had to call on the lazy web to work out how to do this in the end!)

ssURL=paste( sep="", 'http://spreadsheets.google.com/feeds/worksheets/', ssKey, '/public/basic' )
ssd=xmlTreeParse( ssURL, useInternal=TRUE )
nodes=getNodeSet( ssd, "//x:entry", "x" )
titles=sapply( nodes, function(x) xmlSApply( x, xmlValue ) )
data.frame( sheetName = titles['content',], sheetId = str_sub(titles['id',], -3, -1 ) )

data frame in r

In this example, we also pull out the sheet ID that is used by the Google spreadsheets API to access individual sheets, just in case. (Note that these IDs are not the same as the numeric gid values used in the chart API query language…)

PS Note: my version of R seemed to choke if I gave it https: headed URLs, but it was fine with http: