Code.gs

/**
 * @OnlyCurrentDoc
 *
 * The above comment directs Apps Script to limit the scope of file
 * access for this add-on. It specifies that this add-on will only
 * attempt to read or modify the files in which the add-on is used,
 * and not all of the user's files. The authorization request message
 * presented to users will reflect this limited scope.
 */

/**
 * A global constant String holding the title of the add-on. This is
 * used to identify the add-on in the notification emails.
 */
var ADDON_TITLE = 'Form Notifications';

/**
 * A global constant 'notice' text to include with each email
 * notification.
 */
var NOTICE = "Form Notifications was created as an sample add-on, and is meant for \
demonstration purposes only. It should not be used for complex or important \
workflows. The number of notifications this add-on produces are limited by the \
owner's available email quota; it will not send email notifications if the \
owner's daily email quota has been exceeded. Collaborators using this add-on on \
the same form will be able to adjust the notification settings, but will not be \
able to disable the notification triggers set by other collaborators.";


 /**
  * Adds a custom menu to the active form to show the add-on sidebar.
  *
  * @param {object} e The event parameter for a simple onOpen trigger. To
  *     determine which authorization mode (ScriptApp.AuthMode) the trigger is
  *     running in, inspect e.authMode.
  */
function onOpen(e) {
  FormApp.getUi()
      .createAddonMenu()
      .addItem('Configure notifications', 'showSidebar')
      .addItem('About', 'showAbout')
      .addToUi();
}

/**
 * Runs when the add-on is installed.
 *
 * @param {object} e The event parameter for a simple onInstall trigger. To
 *     determine which authorization mode (ScriptApp.AuthMode) the trigger is
 *     running in, inspect e.authMode. (In practice, onInstall triggers always
 *     run in AuthMode.FULL, but onOpen triggers may be AuthMode.LIMITED or
 *     AuthMode.NONE).
 */
function onInstall(e) {
  onOpen(e);
}

/**
 * Opens a sidebar in the form containing the add-on's user interface for
 * configuring the notifications this add-on will produce.
 */
function showSidebar() {
  var ui = HtmlService.createHtmlOutputFromFile('Sidebar')
      .setTitle('Form Notifications');
  FormApp.getUi().showSidebar(ui);
}

/**
 * Opens a purely-informational dialog in the form explaining details about
 * this add-on.
 */
function showAbout() {
  var ui = HtmlService.createHtmlOutputFromFile('About')
      .setWidth(420)
      .setHeight(270);
  FormApp.getUi().showModalDialog(ui, 'About Form Notifications');
}

/**
 * Save sidebar settings to this form's Properties, and update the onFormSubmit
 * trigger as needed.
 *
 * @param {Object} settings An Object containing key-value
 *      pairs to store.
 */
function saveSettings(settings) {
  PropertiesService.getDocumentProperties().setProperties(settings);
  adjustFormSubmitTrigger();
}

/**
 * Queries the User Properties and adds additional data required to populate
 * the sidebar UI elements.
 *
 * @return {Object} A collection of Property values and
 *     related data used to fill the configuration sidebar.
 */
function getSettings() {
  var settings = PropertiesService.getDocumentProperties().getProperties();

  // Use a default email if the creator email hasn't been provided yet.
  if (!settings.creatorEmail) {
    settings.creatorEmail = Session.getEffectiveUser().getEmail();
  }

  // Get text field items in the form and compile a list
  //   of their titles and IDs.
  var form = FormApp.getActiveForm();
  var textItems = form.getItems(FormApp.ItemType.TEXT);
  settings.textItems = [];
  for (var i = 0; i < textItems.length; i++) {
    settings.textItems.push({
      title: textItems[i].getTitle(),
      id: textItems[i].getId()
    });
  }
  return settings;
}

/**
 * Adjust the onFormSubmit trigger based on user's requests.
 */
function adjustFormSubmitTrigger() {
  var form = FormApp.getActiveForm();
  var triggers = ScriptApp.getUserTriggers(form);
  var settings = PropertiesService.getDocumentProperties();
  var triggerNeeded =
      settings.getProperty('creatorNotify') == 'true' ||
      settings.getProperty('respondentNotify') == 'true';

  // Create a new trigger if required; delete existing trigger
  //   if it is not needed.
  var existingTrigger = null;
  for (var i = 0; i < triggers.length; i++) {
    if (triggers[i].getEventType() == ScriptApp.EventType.ON_FORM_SUBMIT) {
      existingTrigger = triggers[i];
      break;
    }
  }
  if (triggerNeeded && !existingTrigger) {
    var trigger = ScriptApp.newTrigger('respondToFormSubmit')
        .forForm(form)
        .onFormSubmit()
        .create();
  } else if (!triggerNeeded && existingTrigger) {
    ScriptApp.deleteTrigger(existingTrigger);
  }
}

/**
 * Responds to a form submission event if a onFormSubmit trigger has been
 * enabled.
 *
 * @param {Object} e The event parameter created by a form
 *      submission; see
 *      https://developers.google.com/apps-script/understanding_events
 */
function respondToFormSubmit(e) {
  var settings = PropertiesService.getDocumentProperties();
  var authInfo = ScriptApp.getAuthorizationInfo(ScriptApp.AuthMode.FULL);

  // Check if the actions of the trigger require authorizations that have not
  // been supplied yet -- if so, warn the active user via email (if possible).
  // This check is required when using triggers with add-ons to maintain
  // functional triggers.
  if (authInfo.getAuthorizationStatus() ==
      ScriptApp.AuthorizationStatus.REQUIRED) {
    // Re-authorization is required. In this case, the user needs to be alerted
    // that they need to reauthorize; the normal trigger action is not
    // conducted, since it authorization needs to be provided first. Send at
    // most one 'Authorization Required' email a day, to avoid spamming users
    // of the add-on.
    sendReauthorizationRequest();
  } else {
    // All required authorizations has been granted, so continue to respond to
    // the trigger event.

    // Check if the form creator needs to be notified; if so, construct and
    // send the notification.
    if (settings.getProperty('creatorNotify') == 'true') {
      sendCreatorNotification();
    }

    // Check if the form respondent needs to be notified; if so, construct and
    // send the notification. Be sure to respect the remaining email quota.
    if (settings.getProperty('respondentNotify') == 'true' &&
        MailApp.getRemainingDailyQuota() > 0) {
      sendRespondentNotification(e.response);
    }
  }
}


/**
 * Called when the user needs to reauthorize. Sends the user of the
 * add-on an email explaining the need to reauthorize and provides
 * a link for the user to do so. Capped to send at most one email
 * a day to prevent spamming the users of the add-on.
 */
function sendReauthorizationRequest() {
  var settings = PropertiesService.getDocumentProperties();
  var authInfo = ScriptApp.getAuthorizationInfo(ScriptApp.AuthMode.FULL);
  var lastAuthEmailDate = settings.getProperty('lastAuthEmailDate');
  var today = new Date().toDateString();
  if (lastAuthEmailDate != today) {
    if (MailApp.getRemainingDailyQuota() > 0) {
      var template =
          HtmlService.createTemplateFromFile('AuthorizationEmail');
      template.url = authInfo.getAuthorizationUrl();
      template.notice = NOTICE;
      var message = template.evaluate();
      MailApp.sendEmail(Session.getEffectiveUser().getEmail(),
          'Authorization Required',
          message.getContent(), {
            name: ADDON_TITLE,
            htmlBody: message.getContent()
          });
    }
    settings.setProperty('lastAuthEmailDate', today);
  }
}

/**
 * Sends out creator notification email(s) if the current number
 * of form responses is an even multiple of the response step
 * setting.
 */
function sendCreatorNotification() {
  var form = FormApp.getActiveForm();
  var settings = PropertiesService.getDocumentProperties();
  var responseStep = settings.getProperty('responseStep');
  responseStep = responseStep ? parseInt(responseStep) : 10;

  // If the total number of form responses is an even multiple of the
  // response step setting, send a notification email(s) to the form
  // creator(s). For example, if the response step is 10, notifications
  // will be sent when there are 10, 20, 30, etc. total form responses
  // received.
  if (form.getResponses().length % responseStep == 0) {
    var addresses = settings.getProperty('creatorEmail').split(',');
    if (MailApp.getRemainingDailyQuota() > addresses.length) {
      var template =
          HtmlService.createTemplateFromFile('CreatorNotification');
      template.summary = form.getSummaryUrl();
      template.responses = form.getResponses().length;
      template.title = form.getTitle();
      template.responseStep = responseStep;
      template.formUrl = form.getEditUrl();
      template.notice = NOTICE;
      var message = template.evaluate();
      MailApp.sendEmail(settings.getProperty('creatorEmail'),
          form.getTitle() + ': Form submissions detected',
          message.getContent(), {
            name: ADDON_TITLE,
            htmlBody: message.getContent()
          });
    }
  }
}

/**
 * Sends out respondent notificiation emails.
 *
 * @param {FormResponse} response FormResponse object of the event
 *      that triggered this notification
 */
function sendRespondentNotification(response, aboutText) {
  var form = FormApp.getActiveForm();
  var settings = PropertiesService.getDocumentProperties();
  var emailId = settings.getProperty('respondentEmailItemId');
  var emailItem = form.getItemById(parseInt(emailId));
  var respondentEmail = response.getResponseForItem(emailItem)
      .getResponse();
  if (respondentEmail) {
    var template =
        HtmlService.createTemplateFromFile('RespondentNotification');
    template.paragraphs = settings.getProperty('responseText').split('\n');
    template.notice = NOTICE;
    var message = template.evaluate();
    MailApp.sendEmail(respondentEmail,
        'Thank you for filling out form ' + form.getTitle() + '!',
        message.getContent(), {
          name: form.getTitle(),
            htmlBody: message.getContent()
        });
  }
}