Schedule meetings from Google Chat

Coding level: Intermediate
Duration: 25 minutes
Project type: Google Chat app

Objectives

  • Understand what the solution does.
  • Understand what the Apps Script services do within the solution.
  • Set up your environment.
  • Set up the script.
  • Run the script.

About this solution

Schedule a meeting in Google Calendar from within a direct message (DM) or a space in Google Chat. You can set specific details for the meeting, such as subject, start time, or duration, or use the default settings for instant meeting scheduling.

Dialog interface of the Meeting Scheduler Chat app

How it works

The Chat app script uses slash commands and dialogs to get meeting details from users and schedule a Calendar event. The script includes default meeting settings that can be customized to fit your needs.

Apps Script services

This solution uses the following services:

  • Calendar service–Creates the calendar event from the provided meeting info.
  • Base service–Uses the Session class to get the script's time zone. Calendar uses this time zone when scheduling the event.
  • Utilities service–Formats the date for the calendar event and encodes the event ID to help get the event URL.

Prerequisites

To use this sample, you need the following prerequisites:

  • A Google Account (Google Workspace accounts might require administrator approval).
  • A web browser with access to the internet.
  • A Google Cloud project.

Set up your environment

Open your Cloud project in the Google Cloud console

If it's not open already, open the Cloud project that you intend to use for this sample:

  1. In the Google Cloud console, go to the Select a project page.

    Select a Cloud project

  2. Select the Google Cloud project you want to use. Or, click Create project and follow the on-screen instructions. If you create a Google Cloud project, you might need to turn on billing for the project.

Turn on the API

Before using Google APIs, you need to turn them on in a Google Cloud project. You can turn on one or more APIs in a single Google Cloud project.

All Chat apps require a consent screen configuration. Configuring your app's OAuth consent screen defines what Google displays to users and registers your app so you can publish it later.

  1. In the Google Cloud console, go to Menu > APIs & Services > OAuth consent screen.

    Go to OAuth consent screen

  2. For User type select Internal, then click Create.
  3. Complete the app registration form, then click Save and Continue.
  4. For now, you can skip adding scopes and click Save and Continue. In the future, when you create an app for use outside of your Google Workspace organization, you must change the User type to External, and then, add the authorization scopes that your app requires.

  5. Review your app registration summary. To make changes, click Edit. If the app registration looks OK, click Back to Dashboard.

Set up the script

Create the Apps Script project

  1. Click the following button to open the Schedule meetings from Google Chat Apps Script project.
    Open the project
  2. Click Overview .
  3. On the overview page, click Make a copy The icon for making a copy.

Copy the Cloud project number

  1. In the Google Cloud console, go to Menu > IAM & Admin > Settings.

    Go to IAM & Admin Settings

  2. In the Project number field, copy the value.

Set the Apps Script project's Cloud project

  1. In your copied Apps Script project, click Project Settings The icon for project settings.
  2. Under Google Cloud Platform (GCP) Project, click Change project.
  3. In GCP project number, paste the Google Cloud project number.
  4. Click Set project.

Create a test deployment

  1. In your copied Apps Script project, click Deploy > Test deployments.
  2. Copy the Head deployment ID for use in a later step and click Done.

Configure the Chat API

  1. In the Google Cloud console, go to the Chat API page.
    Go to Chat API
  2. Click Configuration.
  3. Configure the Chat API with the following information:
    • Name: Meeting Scheduler
    • Avatar URL: Add a URL that points to an image with a minimum size of 256x256 pixels.
    • Description: Quickly create meetings.
    • Functionality: Check both boxes to let users message the app directly and add it to spaces.
    • Connection settings: Click Apps Script and enter the head deployment ID.
    • Slash commands: Add slash commands for /help and /schedule_Meeting by taking the following steps:
      1. Click Add slash command and configure it with the following information:
        • Name: /help
        • Command ID: 1
        • Description: Learn what this app does.
      2. Click Add slash command again and configure it with the following information:
        • Name: /schedule_Meeting
        • Command ID: 2
        • Description: Schedule a meeting.
        • Check the Opens a dialog box.
    • Permissions: Select Specific people and groups in your domain and enter your email address.
  4. Click Save and refresh the page.
  5. On the configuration page, under App status, set the status to Live - available to users.
  6. Click Save.

Run the script

  1. Open Google Chat.
  2. Click Start a chat .
  3. Search for the app's name, Meeting Scheduler.
  4. Send an initial message, such as hello, to prompt authorization.
  5. When the app replies, click Configure and authorize the app. If the OAuth consent screen displays the warning, This app isn't verified, continue by selecting Advanced > Go to {Project Name} (unsafe).

  6. Send /schedule_Meeting to the app.

  7. In the dialog, add at least one invitee email address. You can update the other fields or use the default entries.

  8. Click Submit.

  9. To view the meeting, click Open Calendar event.

Review the code

To review the Apps Script code for this solution, click View source code below:

View source code

Code.gs

solutions/schedule-meetings/Code.js
// To learn how to use this script, refer to the documentation:
// https://developers.google.com/apps-script/samples/chat-apps/schedule-meetings

/*
Copyright 2022 Google LLC

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    https://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

// Application constants
const APPNAME = 'Chat Meeting Scheduler';
const SLASHCOMMAND = {
  HELP: 1, // /help
  DIALOG: 2, // /schedule_Meeting
};

/**
 * Responds to an ADDED_TO_SPACE event in Google Chat.
 * Called when the Chat app is added to a space. The Chat app can either be directly added to the space
 * or added by a @mention. If the Chat app is added by a @mention, the event object includes a message property. 
 * Returns a Message object, which is usually a welcome message informing users about the Chat app.
 *
 * @param {Object} event The event object from Google Chat
 */
function onAddToSpace(event) {
  let message = '';

  // Personalizes the message depending on how the Chat app is called.
  if (event.space.singleUserBotDm) {
    message = `Hi ${event.user.displayName}!`;
  } else {
    const spaceName = event.space.displayName ? event.space.displayName : "this chat";
    message = `Hi! Thank you for adding me to ${spaceName}`;
  }

  // Lets users know what they can do and how they can get help.
  message = message + '/nI can quickly schedule a meeting for you with just a few clicks.' +
    'Try me out by typing */schedule_Meeting*. ' +
    '/nTo learn what else I can do, type */help*.'

  return { "text": message };
}

/**
 * Responds to a MESSAGE event triggered in Chat.
 * Called when the Chat app is already in the space and the user invokes it via @mention or / command.
 * Returns a message object containing the Chat app's response. For this Chat app, the response is either the
 * help text or the dialog to schedule a meeting.
 * 
 * @param {object} event The event object from Google Chat
 * @return {object} JSON-formatted response as text or Card message
 */
function onMessage(event) {

  // Handles regular onMessage logic.
  // Evaluates if and handles for all slash commands.
  if (event.message.slashCommand) {
    switch (event.message.slashCommand.commandId) {

      case SLASHCOMMAND.DIALOG: // Displays meeting dialog for /schedule_Meeting.

        // TODO update this with your own logic to set meeting recipients, subjects, etc (e.g. a group email).
        return getInputFormAsDialog_({
          invitee: '',
          startTime: getTopOfHourDateString_(),
          duration: 30,
          subject: 'Status Stand-up',
          body: 'Scheduling a quick status stand-up meeting.'
        });

      case SLASHCOMMAND.HELP: // Responds with help text for /help.
        return getHelpTextResponse_();

      /* TODO Add other use cases here. E.g:
      case SLASHCOMMAND.NEW_FEATURE:  // Your Feature Here
        getDialogForAddContact(message);
      */

    }
  }
  else {
    // Returns text if users didn't invoke a slash command.
    return { text: 'No action taken - use Slash Commands.' }
  }
}

/**
 * Responds to a CARD_CLICKED event triggered in Chat.
 * @param {object} event the event object from Chat
 * @return {object} JSON-formatted response
 * @see https://developers.google.com/chat/api/guides/message-formats/events
 */
function onCardClick(event) {
  if (event.action.actionMethodName === 'handleFormSubmit') {
    const recipients = getFieldValue_(event.common.formInputs, 'email');
    const subject = getFieldValue_(event.common.formInputs, 'subject');
    const body = getFieldValue_(event.common.formInputs, 'body');

    // Assumes dialog card inputs for date and times are in the correct format. mm/dd/yyy HH:MM
    const dateTimeInput = getFieldValue_(event.common.formInputs, 'date');
    const startTime = getStartTimeAsDateObject_(dateTimeInput);
    const duration = Number(getFieldValue_(event.common.formInputs, 'duration'));

    // Handles instances of missing or invalid input parameters.
    const errors = [];

    if (!recipients) {
      errors.push('Missing or invalid recipient email address.');
    }
    if (!subject) {
      errors.push('Missing subject line.');
    }
    if (!body) {
      errors.push('Missing event description.');
    }
    if (!startTime) {
      errors.push('Missing or invalid start time.');
    }
    if (!duration || isNaN(duration)) {
      errors.push('Missing or invalid duration');
    }
    if (errors.length) {
      // Redisplays the form if missing or invalid inputs exist.
      return getInputFormAsDialog_({
        errors,
        invitee: recipients,
        startTime: dateTimeInput,
        duration,
        subject,
        body
      });
    }

    //  Calculates the end time via duration.
    const endTime = new Date(startTime.valueOf());
    endTime.setMinutes(endTime.getMinutes() + duration);

    // Creates calendar event with notification.
    const calendar = CalendarApp.getDefaultCalendar()
    const scheduledEvent = calendar.createEvent(subject,
      startTime,
      endTime,
      {
        guests: recipients,
        sendInvites: true,
        description: body + '\nThis meeting scheduled by a Google Chat App!'
      });

    // Gets a link to the Calendar event.
    const url = getCalendarEventURL_(scheduledEvent, calendar)

    return getConfirmationDialog_(url);

  } else if (event.action.actionMethodName === 'closeDialog') {

    // Returns this dialog as success.
    return {
      actionResponse: {
        type: 'DIALOG',
        dialog_action: {
          actionStatus: 'OK'
        }
      }
    }
  }
}

/**
 * Responds with help text about this Chat app.
 * @return {string} The help text as seen below
 */
function getHelpTextResponse_() {
  const help = `*${APPNAME}* lets you quickly create meetings from Google Chat. Here\'s a list of all its commands:
  \`/schedule_Meeting\`  Opens a dialog with editable, preset parameters to create a meeting event
  \`/help\`  Displays this help message

  Learn more about creating Google Chat apps at https://developers.google.com/chat.`

  return { 'text': help }
}

Dialog.gs

solutions/schedule-meetings/Dialog.js
/**
 * Copyright 2022 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
* Form input dialog as JSON.
* @return {object} JSON-formatted cards for the dialog.
*/
function getInputFormAsDialog_(options) {
  const form = getForm_(options);
  return {
    'actionResponse': {
      'type': 'DIALOG',
      'dialogAction': {
        'dialog': {
          'body': form
        }
      }
    }
  };
}

/**
* Form JSON to collect inputs regarding the meeting.
* @return {object} JSON-formatted cards.
*/
function getForm_(options) {
  const sections = [];

  // If errors present, display additional section with validation messages.
  if (options.errors && options.errors.length) {
    let errors = options.errors.reduce((str, err) => `${str}• ${err}<br>`, '');
    errors = `<b>Errors:</b><br><font color="#ba0000">${errors}</font>`;
    const errorSection = {
      'widgets': [
        {
          textParagraph: {
            text: errors
          }
        }
      ]
    }
    sections.push(errorSection);
  }
  let formSection = {
    'header': 'Schedule meeting and send email to invited participants',
    'widgets': [
      {
        'textInput': {
          'label': 'Event Title',
          'type': 'SINGLE_LINE',
          'name': 'subject',
          'value': options.subject
        }
      },
      {
        'textInput': {
          'label': 'Invitee Email Address',
          'type': 'SINGLE_LINE',
          'name': 'email',
          'value': options.invitee,
          'hintText': 'Add team group email'
        }
      },
      {
        'textInput': {
          'label': 'Description',
          'type': 'MULTIPLE_LINE',
          'name': 'body',
          'value': options.body
        }
      },
      {
        'textInput': {
          'label': 'Meeting start date & time',
          'type': 'SINGLE_LINE',
          'name': 'date',
          'value': options.startTime,
          'hintText': 'mm/dd/yyyy H:MM'
        }
      },
      {
        'selectionInput': {
          'type': 'DROPDOWN',
          'label': 'Meeting Duration',
          'name': 'duration',
          'items': [
            {
              'text': '15 minutes',
              'value': '15',
              'selected': options.duration === 15
            },
            {
              'text': '30 minutes',
              'value': '30',
              'selected': options.duration === 30
            },
            {
              'text': '45 minutes',
              'value': '45',
              'selected': options.duration === 45
            },
            {
              'text': '1 Hour',
              'value': '60',
              'selected': options.duration === 60
            },
            {
              'text': '1.5 Hours',
              'value': '90',
              'selected': options.duration === 90
            },
            {
              'text': '2 Hours',
              'value': '120',
              'selected': options.duration === 120
            }
          ]
        }
      }
    ],
    'collapsible': false
  };
  sections.push(formSection);
  const card =  {
    'sections': sections,
    'name': 'Google Chat Scheduled Meeting',
    'fixedFooter': {
      'primaryButton': {
        'text': 'Submit',
        'onClick': {
          'action': {
            'function': 'handleFormSubmit'
          }
        },
        'altText': 'Submit'
      }
    }
  };
  return card;
}

/**
* Confirmation dialog after a calendar event is created successfully.
* @param {string} url The Google Calendar Event url for link button
* @return {object} JSON-formatted cards for the dialog
*/
function getConfirmationDialog_(url) {
  return {
    'actionResponse': {
      'type': 'DIALOG',
      'dialogAction': {
        'dialog': {
          'body': {
            'sections': [
              {
                'widgets': [
                  {
                    'textParagraph': {
                      'text': 'Meeting created successfully!'
                    },
                    'horizontalAlignment': 'CENTER'
                  },
                  {
                    'buttonList': {
                      'buttons': [
                        {
                          'text': 'Open Calendar Event',
                          'onClick': {
                            'openLink': {
                              'url': url
                            }
                          }
                        }

                      ]
                    },
                    'horizontalAlignment': 'CENTER'
                  }
                ]
              }
            ],
            'fixedFooter': {
              'primaryButton': {
                'text': 'OK',
                'onClick': {
                  'action': {
                    'function': 'closeDialog'
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

Utilities.gs

solutions/schedule-meetings/Utilities.js
/**
 * Copyright 2022 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
* Helper function that gets the field value from the given form input.
* @return {string} 
*/
function getFieldValue_(formInputs, fieldName) {
  return formInputs[fieldName][''].stringInputs.value[0];
}

// Regular expression to validate the date/time input.
const DATE_TIME_PATTERN = /\d{1,2}\/\d{1,2}\/\d{4}\s+\d{1,2}:\d\d/;

/**
* Casts date and time from string to Date object.
* @return {date} 
*/
function getStartTimeAsDateObject_(dateTimeStr) {
  if (!dateTimeStr || !dateTimeStr.match(DATE_TIME_PATTERN)) {
    return null;
  }

  const parts = dateTimeStr.split(' ');
  const [month, day, year] = parts[0].split('/').map(Number);
  const [hour, minute] = parts[1].split(':').map(Number);


  Session.getScriptTimeZone()

  return new Date(year, month - 1, day, hour, minute)
}

/** 
* Gets the current date and time for the upcoming top of the hour (e.g. 01/25/2022 18:00).
* @return {string} date/time in mm/dd/yyy HH:MM format needed for use by Calendar
*/
function getTopOfHourDateString_() {
  const date = new Date();
  date.setHours(date.getHours() + 1);
  date.setMinutes(0, 0, 0);
  // Adding the date as string might lead to an incorrect response due to time zone adjustments.
  return Utilities.formatDate(date, Session.getScriptTimeZone(), 'MM/dd/yyyy H:mm');
}


/** 
* Creates the URL for the Google Calendar event.
*
* @param {object} event The Google Calendar Event instance
* @param {object} cal The associated Google Calendar 
* @return {string} URL in the form of 'https://www.google.com/calendar/event?eid={event-id}'
*/
function getCalendarEventURL_(event, cal) {
  const baseCalUrl = 'https://www.google.com/calendar';
  // Joins Calendar Event Id with Calendar Id, then base64 encode to derive the event URL.
  let encodedId = Utilities.base64Encode(event.getId().split('@')[0] + " " + cal.getId()).replace(/\=/g, '');
  encodedId = `/event?eid=${encodedId}`;
  return (baseCalUrl + encodedId);

}

Contributors

This sample is maintained by Google with the help of Google Developer Experts.

Next steps