This is a Google Apps Script (https://script.google.com) that replicates the "Snippets" messaging process as used by Google internally. See the notes at the bottom of this page for more info.

weeklyupdate.js

/* **************************************

Weekly Update Scripts
by Dan Brown, March 2013

For automatic collection of weekly
update messages from employees.

* sends reminder messages
* posts to public sites pages
* alerts managers, coworkers and
  other stakeholders

Known Issues:
* html tags should be stripped from subscription messages (ready to test)
* lines beginning with ">" are not being dropped as expected from both announcements
  and subscription messages (might be fixed by previous issue's fix)
* fix link creation in sites list page

Suggestions for improvements:
* include most recent update in reminder (ready to test)
* link to instructions and example
* avoid sending reminder to people who
  already sent an update this round

************************************** */

var domainName = 'your-domain-here.com';
var siteName = 'your-site-name-here';
var site = SitesApp.getSite(domainName, siteName);

var debug = 2; // set to zero to disable logging
var dryRun = 1; // set to 1 to disable writing/sending. for testing


function getTextFromHtml(html) {
  // getTextFromHtml("hello <div>foo</div>&amp; world <br /><div>bar</div>!");
  // will return
  // "hello foo& world bar!"
  // from http://stackoverflow.com/questions/13288928/trouble-with-html-encoding-in-google-apps-script
  // TODO: check to see if <br> tags and others like </li> get converted to newlines
  //       \n: br p li tr, others? (divs are difficult)
  //       space: td
  return getTextFromNode(Xml.parse(html, true).getElement());
}

function getTextFromNode(x) {
  switch(x.toString()) {
    case 'XmlText': return x.toXmlString() + '\n';
    case 'XmlElement': return x.getNodes().map(getTextFromNode).join('');
    default: return '';
  }
}

function cleanString(input) {
  if (typeof(input) === "undefined") { return ""; }
  if (input === null) { return ""; }
  return input.trim().toLowerCase();
}

function parseEmailAddress(input) {
  // we expect it to return a simple [a-z0-9\.]*@[a-z0-9\.]* text string.
  // returns an empty string in case of invalid input
  if (typeof(input) === "undefined") { return ""; }
  if (input === null) { return ""; }
  var email = cleanString(input);
  // remove stuff outside angle braces that gmail adds to addresses
  var iOpenAngle = email.lastIndexOf("<");
  var iCloseAngle = -1; // default
  if (iOpenAngle != -1) {
    iCloseAngle = email.indexOf(">", iOpenAngle);
    if (iCloseAngle != -1) {
      var trimmedEmail = email.substr(iOpenAngle + 1, iCloseAngle - iOpenAngle -1);
      if (debug > 2) {
        Logger.log("Trimming email address: " + email + " --becomes--> " + trimmedEmail);
      }
      email = trimmedEmail;
    }
  }
  iAt = email.indexOf("@");
  iDot = email.indexOf(".", iAt);
  if ((email.length > 0) && (iAt != -1) && (iAt > 0) && (iDot != -1) && (iAt < iDot) && (iDot < (email.length - 1))) {
    return email;
  } else {
    return "";
  };
}

function removeOldThreadContent(input) {
  // attempts to remove lines from a message body that come from older messages in a thread
  // these start with ">" or have the pattern "On ... wrote:"
  var output = [];
  var inputArray = input.split("\n");
  while (inputArray.length) {
    var line = inputArray.shift();
    var linelength = line.length;
    if ((line.substr(0,1) == ">") || (line.substr(0,2) == " >") || (line.substr(0,4) == "&gt;") || (line.substr(0,5) == " &gt;")) {
      // don't include this line
    } else if ((line.substr(0,3) == "On ") && ((line.substr(linelength - 6,6) == "wrote:") || (line.substr(linelength - 12,6) == "wrote:"))) {
      // don't include this line
    } else {
      output.push(line);
    }
  }
  return output.join("\n");
}

var INVALID_DATE = new Date(0); // Jan 1, 1970
var TODAY = new Date();
var THREEDAYSAGO = new Date(TODAY.valueOf() - 259200000);
var TENYEARSAGO = new Date(TODAY.valueOf() - 315569259747);
function parseDateString(input) {
  // converts from ISO format (eg. "2013-01-20T23:45:56.000Z")
  //if (isNaN(input) || (input == "")) { return INVALID_DATE; }
  if (input == "") { return INVALID_DATE; }
  try {
    var date = new Date(input);
  } catch(err) {
    return INVALID_DATE;
  }
  if (date.valueOf() < TENYEARSAGO.valueOf()) {
    return INVALID_DATE;
  }
  return date;
}

function formatDateString(input) {
  // converts to ISO format (eg. "2013-01-20T23:45:56.000Z")
  return input.toISOString();
}

function maxDate(x, y) {
  if ((x == INVALID_DATE) && (y == INVALID_DATE)) { return x; }
  if (x == INVALID_DATE) { return y; }
  if (y == INVALID_DATE) { return x; }
  if (x > y) { return x; }
  return y;
}


function getTextBetween(fullstring, start_marker, end_marker) {
  var startIndex = fullstring.indexOf(start_marker) + start_marker.length;
  if (startIndex == -1) { return ""; }
  var endIndex = fullstring.indexOf(end_marker, startIndex);
  if (endIndex == -1) { return ""; }
  return fullstring.substring(startIndex,endIndex);
}

function createLink(ref, anchor) {
  // URLs are stored as strings in Google Sites,
  // eg. <a xmlns="http://www.w3.org/1999/xhtml" href="/a/your-domain-here.com/your-site-here/who/someone">here</a>
  
  var trimThis = "https://sites.google.com";
  if (ref.slice(0,trimThis.length) === trimThis) {
    ref = ref.slice(trimThis.length);
  }
//  return '<a xmlns="http://www.w3.org/1999/xhtml" href="' + ref + '">' + anchor + '</a>';
  return '<a href="' + ref + '">' + anchor + '</a>';
}

function parseUrl(inputstring) {
  // URLs are stored as strings in Google Sites,
  // eg. <a xmlns="http://www.w3.org/1999/xhtml" href="/a/your-domain-here.com/your-site-here/who/someone">here</a>
  var refStart = 'href="';
  var refEnd = '"';
  var anchorStart = '>';
  var anchorEnd = '<';
  return [getTextBetween(inputstring, refStart, refEnd), getTextBetween(inputstring, anchorStart, anchorEnd)];
}

function getUrlRef(inputstring) {
  return parseUrl(inputstring)[0];
}

function getUrlAnchor(inputstring) {
  return parseUrl(inputstring)[1];
}


var DIRECTORY_PAGE_NAME = "who";
var UPDATES_PAGE_NAME = "updates";

var PAR_FIRSTNAME = "First name";
var PAR_LASTNAME = "Last name";
var PAR_EMAIL = "email";
var PAR_DEPARTMENT = "Department";
var PAR_EMAIL = "email";
var PAR_OBJECTIVES = "Objectives";
var PAR_UPDATES = "Updates";

function getParticipants() {
  if (debug > 0) { Logger.log("starting getParticipants() function"); }
  var directoryPage = site.getChildByName(DIRECTORY_PAGE_NAME);
  var participants = directoryPage.getListItems();
  var participantSeenFirstAtRow = {}; // to ignore duplicates
  var participantsArray = [];
  var participantCount = participants.length;
  for (var i=0; i < participantCount; i++) { // don't need to skip header row, because it won't be a valid email address
    var p = participants[i];
    var rawEmail = p.getValueByName(PAR_EMAIL);
    var recipientEmail = parseEmailAddress(rawEmail);
    // test to see if the row should be skipped
    if (recipientEmail.length === 0) {
      if (debug > 0) {
        Logger.log("Skipping invalid email address " + rawEmail + " found at row " + i);
      }
      continue;
    }
    if (participantSeenFirstAtRow.hasOwnProperty(recipientEmail)) {
      if (debug > 0) {
        Logger.log("Skipping duplicate email address " + recipientEmail + " found at row " + i + ", first seen at row " + participantSeenFirstAtRow[recipientEmail]);
      }
      continue;
    }
    // clean original email if necessary
    if (rawEmail != recipientEmail) {
      p.setValueByName(PAR_EMAIL, recipientEmail);
      if (debug > 0) {
        Logger.log("Replaced original email value (" + rawEmail + ") at row " + i + " with cleaned version (" + recipientEmail + ")");
      }
    }

    if (p.getValueByName(PAR_DEPARTMENT) != "Product Management") {
      continue; // skip this person who is not in PM dept. for testing phase
    }

    // new participant
    participantSeenFirstAtRow[recipientEmail] = i;
    var username = recipientEmail.split("@")[0];
    var pageURLObjectives = cleanString(p.getValueByName(PAR_OBJECTIVES)); // may be blank
    if (pageURLObjectives.length === 0) {
      try {
        var pageObjectives = directoryPage.getChildByName(username);
      } catch (exception) {
        var pageObjectives = site.createWebPage(p.getValueByName(PAR_FIRSTNAME) + " " + p.getValueByName(PAR_LASTNAME), username, "");
      }
      // URLs are strings, eg. "<a xmlns="http://www.w3.org/1999/xhtml" href="/a/getyourguide.com/poca/who/villars">here</a>"
      //p.setValueByName(PAR_OBJECTIVES, pageObjectives.getUrl());
//      p.setValueByName(PAR_OBJECTIVES, createLink(pageObjectives.getUrl(), "here")); // TODO: re-enable once URLs are working (bug?)
//      p.setValueByName(PAR_OBJECTIVES, '<a href="http://who">whourl</a>&nbsp;');
    } else {
      var pageObjectives = directoryPage.getChildByName(username);
    }
    var pageURLToAppend = cleanString(p.getValueByName(PAR_UPDATES)); // may be blank
    if (pageURLToAppend.length === 0) {
      try {
        var pageToAppend = pageObjectives.getChildByName(UPDATES_PAGE_NAME);
      } catch (exception) {
        var pageToAppend = pageObjectives.createAnnouncementsPage("Weekly updates from " + username, UPDATES_PAGE_NAME, "");
      }
      //p.setValueByName(PAR_UPDATES, pageToAppend.getUrl());
//      p.setValueByName(PAR_UPDATES, createLink(pageToAppend.getUrl(), "here")); // TODO: re-enable once URLs are working (bug?)
    } else {
      var pageToAppend = pageObjectives.getChildByName(UPDATES_PAGE_NAME);
    }
    participantsArray.push(p);
  }
  return participantsArray;
}

function getSenderEmail() {
  // we attempt to send from the official email alias for the service
  // that we created and associated with Dan Brown's gmail account (brown@)
  // if that fails, return an empty string
  var senderEmail = "[email protected]";
  if (GmailApp.getAliases().indexOf(senderEmail) != -1) {
    return senderEmail;
  }
  return "";
}

function getPreviousUpdateContent(updatesURL) {
  var previousUpdateContent = ""; // default is an empty string
  try {
    var pageUpdates = SitesApp.getPageByUrl(updatesURL);
    var previousUpdates = pageUpdates.getAnnouncements();
    previousUpdateContent = getTextFromHtml(previousUpdates[previousUpdates.length - 1].getHtmlContent());
    previousUpdateContent = "\n> Your most recent update:\n> " + previousUpdateContent.replace(/\n/g,"\n> ");
  } catch (exception) {
    // no operation
    if (debug > 0) { Logger.log("no previous update found at page " + updatesURL); }
  }
  return previousUpdateContent;
}

function emailReminderMessages() {
  if (debug > 0) { Logger.log("starting emailReminderMessages() function"); }

  // assemble the contents of the message to be sent
  var subject = "Weekly Update reminder";
  var salutation = "> Hello ";
  var body = "\n> Please respond with your weekly update before 15:00 CET today.";
  body += "\n> ";
  body += "\n> Include 3-5 bullet points describing your accomplishments for the past week";
  body += "\n> and 3-5 more describing your plan for next week.";
  body += "\n> It should take less than 5 minutes to write.";
  body += "\n> ";
  body += "\n> Your response will be publicly visible as part of your profile page on our intranet.";
  body += "\n> ";
  var closing = "\n> Lines beginning with \">\" will be ignored.\n";

  // TODO: add reference to instructions and examples
  var extraParams = { name: "Weekly Update" };
  // we prefer to send from the official email alias for the service
  var senderEmail = getSenderEmail();
  if (senderEmail.length > 0) {
    extraParams.from = senderEmail;
    extraParams.replyTo = senderEmail; // TODO: get this to work properly! Or maybe it's because brown@ is also wupdate@, and others will be OK?
  }

  // send a message to each participant that wants to receive a reminder
  var participants = getParticipants();
  while (participants.length) {
    p = participants.shift();
    var email = p.getValueByName(PAR_EMAIL);
    var firstname = p.getValueByName(PAR_FIRSTNAME);
    var updatesURL = "https://sites.google.com" + getUrlRef(p.getValueByName(PAR_UPDATES));
    var previousUpdateContent = getPreviousUpdateContent(updatesURL);
    // TODO: check to see if the person has already sent an update recently, and don't send a reminder if so
//    if (p[LAST] > THREEDAYSAGO) {
//      // TODO: do a Gmail search instead of this P[LAST] check!
//      if (debug > 0) { Logger.log("INFO: no message sent to " + email + " (recent update received on " + p[LAST].toISOString() + ")"); }      
//    } else {
    if (dryRun === 0) {
      GmailApp.sendEmail(email, subject, salutation + firstname + body + updatesURL + closing + previousUpdateContent, extraParams);
    }
    if (debug > 0) { Logger.log("sent message to " + email); }
    if (debug > 1) { Logger.log("content :\n" + salutation + firstname + body + updatesURL + closing + previousUpdateContent); }
//    }
  }
}

// we use escape key names to avoid collisions with existing properties of objects, when used as a dictionary
function escape(input) {
  return "_" + input;
}
function unescape(input) {
  return input.substr(1, input.length-1);
}
function isEscaped(input) {
  return (input.charAt(0) === "_");
}

function addDefaultDomain(rawstring, domain) {
  // add the defaultDomain if the raw Email doesn't end in it
  var atInd = rawstring.indexOf('@');
  if (atInd === -1) {
    return rawstring + '@' + domain;
  } else {
    return rawstring;
  }  
}

var SUBSCRIPTIONS_PAGE_NAME = "--subscriptions";
// schema of "Subscriptions" array
var SUB_ROW = 0;
var SUB_EMAIL = 1;
var SUB_TERM = 2;
var SUB_EMAILFIELD = "Subscriber email (@your-domain-name.com)";
var SUB_TERMFIELD = "receive updates that contain this term";
function getSubscriptions() {
  // Create list of subscriptions to receive copies of relevant update messages
  // each subscription is a list where the first element is the search term,
  // and the second element is the address of a single subscriber
  if (debug > 0) { Logger.log("starting getSubscriptions() function"); }

  var directoryPage = site.getChildByName(DIRECTORY_PAGE_NAME);
  var subscriptionsPage = directoryPage.getChildByName(SUBSCRIPTIONS_PAGE_NAME);
  var subscriptions = subscriptionsPage.getListItems();
  var subscriptionsArray = [];

  var alreadySeenSubscriptions = {};
  var i=-1;
  while (subscriptions.length) {
    i++;
    subscription = subscriptions.shift();
    var rawEmail = addDefaultDomain(subscription.getValueByName(SUB_EMAILFIELD), "your-domain-name.com");
    
    var recipientEmail = parseEmailAddress(rawEmail);
    // test to see if the row should be skipped
    if (recipientEmail.length === 0) {
      if (debug > 0) {
        Logger.log("Skipping invalid email address " + rawEmail + " found at row " + i);
      }
      continue;
    }
    // clean original email if necessary
    if (rawEmail != recipientEmail) {
      subscription.setValueByName(SUB_EMAILFIELD, recipientEmail);
      if (debug > 0) {
        Logger.log("Replaced original email value (" + rawEmail + ") at row " + i + " with cleaned version (" + recipientEmail + ")");
      }
    }

    var searchTerm = subscription.getValueByName(SUB_TERMFIELD);
    var subFingerprint = recipientEmail + "__@@__@@__" + searchTerm;
    if (alreadySeenSubscriptions.hasOwnProperty(subFingerprint)) {
      if (debug > 0) {
        Logger.log("Skipping duplicate subscription on row " + i + " (" + recipientEmail + " : " + searchTerm + ")");
      }
    } else {
      subscriptionsArray.push(subscription);
      alreadySeenSubscriptions[subFingerprint] = true;
    }
  }
  return subscriptionsArray;
}

function groupSubscriptionsBySearchTerm(input) {
  // input should be an array of list items, with no duplicate subscription information
  // returns an array of arrays:
  // each subscription is a list where the first element is the search term,
  // and the second element is the address of a single subscriber
  // and all following elements are email addresses of subscribers
  var subscriptions = {};
  while (input.length) {
    s = input.shift();
 
    var recipientEmail = escape(addDefaultDomain(s.getValueByName(SUB_EMAILFIELD), "getyourguide.com"));
    var escapedSearchTerm = escape(s.getValueByName(SUB_TERMFIELD));
    if (!(subscriptions.hasOwnProperty(escapedSearchTerm))) {
      subscriptions[escapedSearchTerm] = [];
    }
    subscriptions[escapedSearchTerm].push(recipientEmail);
  }
  // filter and flatten object data structure into an array of arrays
  var unescapedSubscriptions = [];
  for (escapedSearchTerm in subscriptions) {
    if (isEscaped(escapedSearchTerm)) {
      var pushThis = subscriptions[escapedSearchTerm];
      pushThis.unshift(unescape(escapedSearchTerm));
      unescapedSubscriptions.push(pushThis);
    }
  }
  return unescapedSubscriptions;
}

function checkForResponseMessages() {
  if (debug > 0) { Logger.log("starting checkForResponseMessages() function"); }
  // remember start time and exclude messages received after that time
  var functionStartTime = new Date();

  // Look for the time of the last run in the subscriptions page description. It is expected
  // to be in a specific text string.
  var functionLastRunTime = parseDateString(""); // default to invalid date
  var directoryPage = site.getChildByName(DIRECTORY_PAGE_NAME);
  var subscriptionsPage = directoryPage.getChildByName(SUBSCRIPTIONS_PAGE_NAME);
  var subscriptionPageText = subscriptionsPage.getHtmlContent();
  var last_updated_marker_start = "[Last publish to subscribers was on ";
  var last_updated_marker_end = "]";
  var last_updated_start_index = subscriptionPageText.indexOf(last_updated_marker_start);
  var last_updated_end_index = -1; //default
  if (last_updated_start_index != -1) {
    last_updated_start_index += last_updated_marker_start.length;
    last_updated_end_index = subscriptionPageText.indexOf(last_updated_marker_end, last_updated_start_index);
    if (last_updated_end_index != -1) {
      var functionLastRunTimeString = subscriptionPageText.substring(last_updated_start_index, last_updated_end_index);
      var functionLastRunTime = parseDateString(functionLastRunTimeString);
    }
  }

  var directoryPage = site.getChildByName(DIRECTORY_PAGE_NAME);

  // Create set of subscriptions to receive copies of relevant update messages
  var groupedSubscriptions = groupSubscriptionsBySearchTerm(getSubscriptions());

  // Get instructions for where to record information for each participant
  var participants = getParticipants();

  // assemble the contents of the message to be sent
  var subject = "Weekly Update subscription";
  var extraParams = { name: "Weekly Update" };
  // we prefer to send from the official email alias for the service
  var senderEmail = getSenderEmail();
  if (senderEmail.length > 0) {
    extraParams.from = senderEmail;
    extraParams.replyTo = senderEmail; // TODO: get this to work properly!
  }

  var messagesFor = {}; // store the messages relevant to each subscriber
  // data structure schema:
  // messagesFor[escapedSubscriberEmail][escapedMessageID] = [array of searchTerms]
  
  while (participants.length) {
    p = participants.shift();
    // Look for new messages from this participant
    var query = "from:" + p.getValueByName(PAR_EMAIL);
    if (senderEmail.length > 0) {
      query += " to:" + senderEmail;
    }
    //var lastHeardFrom = parseDateString(""); // Date object (aka epoch milliseconds) // TODO: implement last-heard-from cutoff, maybe using the list page's created/updated times?
    var lastHeardFrom = functionLastRunTime;
    if (lastHeardFrom != INVALID_DATE) {
      var dateString = lastHeardFrom.toISOString().split("T")[0];
      query += " after:" + dateString;
    }
    var latestDate = INVALID_DATE;
    if (debug > 0) { Logger.log("\n*** searching for messages with query: " + query); }
    var threads = GmailApp.search(query);
    if (debug > 1) { Logger.log("found " + threads.length + " threads to examine"); }
    while (threads.length) {
      t = threads.shift();
      messages = t.getMessages();
      if (debug > 1) { Logger.log("  found " + messages.length + " in this thread"); }
      while (messages.length) {
        m = messages.shift();
        var mdate = m.getDate();
        var mfrom = parseEmailAddress(m.getFrom());
        // check for skip conditions
        if (m.isInTrash()) {
          if (debug > 1) { Logger.log("    skipping trashed message"); }
          continue;
        }
        if (mfrom != p.getValueByName(PAR_EMAIL)) {
          if (debug > 1) { Logger.log("    skipping message from " + mfrom + " because it doesnt match " + p.getValueByName(PAR_EMAIL)); }
          continue;
        }
        if ((lastHeardFrom != INVALID_DATE) && (mdate < lastHeardFrom)) {
          if (debug > 1) { Logger.log("    skipping message sent on " + mdate.toISOString() + " which is earlier than " + lastHeardFrom.toISOString()); }
          continue;
        }
        if (mdate > functionStartTime) {
          if (debug > 1) { Logger.log("    skipping message sent on " + mdate.toISOString() + " which is after this script started at " + functionStartTime.toISOString()); }
          continue;
        }
        var newContent = removeOldThreadContent(getTextFromHtml(m.getBody())); // TODO: check to see if newlines are handled appropriately when input formatted with html tags
        if (newContent.length === 0) {
          if (debug > 1) { Logger.log("    skipping message sent on " + mdate.toISOString() + " which has no new content"); }
          continue;
        }

        // this message passed all the tests, so we accept it
        latestDate = maxDate(latestDate, mdate);
        if (debug > 0) { Logger.log("    found new message from " + mfrom + " sent on " + mdate.toISOString()); }
        if (debug > 2) { Logger.log("    latestDate is now " + latestDate.toISOString()); }

        // append this content to the person's google site page // TODO: make sure this page exists, and create it if necessary
        var username = mfrom.split("@")[0];
        var appendToPage = directoryPage.getChildByName(username).getChildByName(UPDATES_PAGE_NAME);

        if (debug > 0) {
          Logger.log("Creating new announcement on " + appendToPage.getUrl());
        }
        if (dryRun === 0) {
          appendToPage.createAnnouncement(mdate.toISOString(), newContent);
        }
        
        // check to see if any subscribers should be notified of this message
        for (var i=0; i<groupedSubscriptions.length; i++) {
          var s = groupedSubscriptions[i];
          var searchTerm = s[0];
          var searchRegEx = /\bsearchTerm\b/i; // to require word boundaries at start and end of search term
//          if ((mfrom == searchTerm) || (newContent.indexOf(searchTerm) != -1)) {
          if ((mfrom == searchTerm) || (searchRegEx.test(newContent))) {
            for (var j=1; j<s.length; j++) { // start at second term in array
              var escapedSubscriber = s[j]; // it's already escaped
              if (!(messagesFor.hasOwnProperty(escapedSubscriber))) {
                messagesFor[escapedSubscriber] = {};
              }
              var messagesForSubscriber = messagesFor[escapedSubscriber];
              var escapedMessageId = escape(m.getId());
              if (!(messagesForSubscriber.hasOwnProperty(escapedMessageId))) {
                messagesForSubscriber[escapedMessageId] = [];
              }
              messagesForSubscriber[escapedMessageId].push(searchTerm);
            }
          }
        }
      }
    }
    // maybe todo: store the time stamp of the most recent message received from this participant

  }
  
  // send messages to subscribers
  // batch all notifications into as few messages as possible (limit 20kB)
  
  for (var escapedSubscriber in messagesFor) {
    if (isEscaped(escapedSubscriber)) {
      var subscriber = unescape(escapedSubscriber);
      if (debug > 1) { Logger.log("preparing notification messages for " + subscriber); }
      var content = "";
      for (var escapedMessageId in messagesFor[escapedSubscriber]) {
        if (isEscaped(escapedMessageId)) {
          var messageId = unescape(escapedMessageId);
          var message = GmailApp.getMessageById(messageId);
          var searchTerms = messagesFor[escapedSubscriber][escapedMessageId];
          content += "\n----- found search term(s): " + searchTerms.join(" , ");
          content += "\n----- in message from " + message.getFrom() + " sent " + message.getDate().toISOString();
          content += "\n" + removeOldThreadContent(getTextFromHtml(message.getBody())); // TODO: check newlines from html handled properly
          content += "\n----------------------------\n";
          if (debug > 1) { Logger.log("found message (ID = " + messageId + ") regarding search term(s) " + searchTerms.join(" , ")); }
          if (content.length > 15000) { // send this now if the message is approaching the 20kb limit
            if (debug > 0) { Logger.log("sending message to " + subscriber + " triggered by large message accumulator size"); }
            if (dryRun === 0) {
              GmailApp.sendEmail(subscriber, subject, content, extraParams);
            }
            content = "";
          }
        }
      }
      if (content.length !== 0) {
        if (debug > 0) { Logger.log("sending message to " + subscriber); }
        if (dryRun === 0) {
          GmailApp.sendEmail(subscriber, subject, content, extraParams);
        }
      }
    }
  }

  if (functionStartTime != INVALID_DATE) {
    // Store the time of this run in the subscriptions page description for future reference.
    if ((last_updated_start_index === -1) || (last_updated_end_index === -1)) {
      var newSubscriptionPageText = subscriptionPageText + "\n" + last_updated_marker_start +
        formatDateString(functionStartTime) + last_updated_marker_end;
    } else {
      var newSubscriptionPageText = subscriptionPageText.substring(0,last_updated_start_index) +
        formatDateString(functionStartTime) + subscriptionPageText.substring(last_updated_end_index);
    }
    if (debug > 0) { Logger.log("updating last run time on subscriptions page to " + formatDateString(functionStartTime)); }
    if (dryRun === 0) {
      subscriptionsPage.setHtmlContent(newSubscriptionPageText);
    }
  }
  
}

function onOpen() {
  // create some convenient manual trigger menu options
  var subMenus = [
    {name:"Send Reminder Email Messages Now", functionName: "emailReminderMessages"},
    {name:"Check For Response Messages Now", functionName: "checkForResponseMessages"}
  ];
  SpreadsheetApp.getActiveSpreadsheet().addMenu("Weekly Update Automated Functions", subMenus);
}

This script does 3 things:

• reminds people to send in a weekly update of tasks done this week and planned for next week.
• collects responses and stores them in a permanent place
• notifies subscribers of relevant responses by keyword or author

Notes: The script interacts with Google Sites and Gmail. It expects a list page with a company directory to be stored at /who with certain fields present. It has some testing settings (dryrun=1 disables writing and email sending operations). It expects there to be an alias "wupdate@" used to send a received messages.