Satori Chat Demo

Satori provides an API that sends data between apps at high speed. The API uses a publish/subscribe model: Apps publish data of any type to a channel, and other apps subscribe to that channel and retrieve data from it. The API, based on WebSocket, transfers any amount of data with almost no delay.

Satori APIs also let you customize channels:

• Satori streambots subscribe to a channel and execute custom code on each incoming message. You create a streambot using a Satori Java API.
• Satori views select, transform, or aggregate messages from a channel based on criteria you define in SQL.

The chat demo app shows you how the Satori API works. The demo app does the following:

• Creates a Satori channel for publishing chat messages
• Subscribes to the Satori channel so it can receive chat messages from other demo app users.
• Displays a time-limited chat room and lets you invite others to participate.
• Sets up a Satori streambot that provides weather information based on your location.
• Sets up a Satori view that select the weather information from a public Satori channel that gets information from the National Weather Service.

Hint: Send the chat room URL to lots of people and see how well it performs.

Run the online demo

A live version of the demo is available at https://chat.satori.com. To see the demo, open the link in a browser running on a computer and follow the instructions on the screen.

Run the demo locally

You can get the source files for the demo and run it locally. The source includes the browser JavaScript that runs the chat room and the Satori API library. The source also includes a small server that helps with the demo. It's not part of the Satori ecosystem; instead, it helps you offer the demo UI and JavaScript to other computers and mobile devices.

Prerequisites

The demo has these external prerequisites:

• A computer that supports Node.js.
• Node.js version 6.0.0 or later

Ensure that the Node package manager npm is available.

All of the code for the demo is included in the GitHub clone, or it is installed using npm after you have the code.

Set up a Satori project

The demo uses the following Satori features that you set up in your own Satori project:

• Private data channels, which require an appkey and an endpoint.
• User roles for the channels

Satori projects are free. To create one, you need a Satori account, which is also free.

Set up the appkey and endpoint:

1. Log in or sign up for a Satori account at https://developer.satori.com.
2. From the dashboard, navigate to the Projects page.
3. Click Add a project, then enter the name "Chat" and click Add.
4. Satori displays the appkey and endpoint for your project. Make a copy of the values. After you get the demo code, you add the values to a config file.
5. Click Save.

Set up the "user" and "admin" user roles :

1. Click the Roles tab, then click Add a role.
2. To set up the user role, enter user, then click Add. This returns you to the Roles tab.
3. To set up the admin role, enter admin, then click Add. This returns you to the Roles tab.

Get the role secret key for the user role:

1. On the Roles tab, find the Role secret key column.
2. Copy the role secret key for user. After you get the demo code, you add the key to a config file.

Set up channel permissions for the user user role :

1. In the roles table, click user to display its details page.
2. Click the Channel permission tab.
3. In the table, click the asterisk (*) namespace wildcard to display the Channel permission info page. These channel permissions apply to all channels associated with the user user role.
4. In the table, click the * namespace wildcard to display the Channel permission info page. These channel permissions apply to all channels associated with the user user role.
5. In the "Publish" Action Permission dropdown, select Forbid. Leave "Subscribe" Action Permission set to Permit. Click Save.
6. In the breadcrumbs at the top of the page, click Channel permissions to return to the Channel permission tab.
7. Click Add a channel permission, then enter the following:
   • Namespace: channel-manager
   • "Publish" Action Permission: Select Permit from the dropdown.
   • "Subscribe" Action Permission: Select Forbid from the dropdown.
8. Click Add to save the permissions and return to the details page for the user user role.
9. In the breadcrumbs at the top of the page, Click Roles to return to the Roles tab.

You don't need to set up channel permissions for the admin user role, because the default permissions are sufficient.

Save your work

1. From the Roles tab, click the General tab.
2. Click Save.

Get the demo code

The demo code is available in a public GitHub repository. It's based on React, using the Create React App framework, so you have access to all the tools provided by react-scripts.

1. Clone the demo source files from GitHub:

git clone git@github.com:satori-com/chat.git

1. Build the code

npm install

Note: The Create React App documentation describes the framework in more detail. To learn more about creating Satori projects for your own apps, see the Dev Portal tutorial.

The demo server

The demo code includes a small server. It doesn't have a role in the Satori ecosystem. Instead, it simplifies the demo. On a computer, you can open chat/public/index.html instead of running the server. The HTML loads the demo JavaScript app, which establishes communication with the Satori ecosystem.

Without the server, however, each computer that wants to use the demo has to have a copy of index.html and the JavaScript. Also, the technique only works on computers, because mobile devices don't have a way of opening local HTML files or JavaScript.

With the server running, any computer or device that wants to use the demo can navigate to the server's IP address and port.

Run the demo

Set up the config file

1. In chat-demo, copy the file .env to env.local, then edit .env.local and update it with the appkey, endpoint, role name and role secret key values you copied:

REACT_APP_ENDPOINT='<endpoint_value>'
REACT_APP_APPKEY='<appkey_value>'
REACT_APP_ROLE='<role_name_value>'
REACT_APP_ROLE_SECRET='<role_secret_key_value>'

1. Set the app history value to keep a maximum of 8 hours of chats, expressed in seconds:

REACT_APP_HISTORY_MAX_COUNT='28800'

1. Set the geolocation flag so that the app can give you weather information based on your location:

REACT_APP_USE_GEOLOCATION='true'

1. Save .env.local.

Set up the streambots

Add the streambots to Satori

1. If necessary, log in to https://developer.satori.com.
2. Navigate to the Bots page.
3. Click Add a bot. Enter the following values:
   • Bot name: moderator-bot
   • Platform: Select JavaScript from the dropdown.
   • Executable: Click the file icon, then select chat/bots/moderator-bot.js
4. Click Add.
5. In the breadcrumbs at the top of the page, click Bots to return to the Bots page.
6. Click Add a bot. Enter the following values:
   • Bot name: weather-bot
   • Platform: Select JavaScript from the dropdown.
   • Executable: Click the file icon, then select chat/bots/weather-bot.js.
7. Click Add.

Add streambot instances to the project

First, add the moderator streambot:

1. If necessary, log in to https://developer.satori.com.
2. Navigate to the Projects page.
3. Click chat to open the Chat project details page.
4. On the tab bar, click Bot instances.
5. Click Add a bot instance.
6. Enter the following values:
   • Bot name: moderator-bot
   • Role: admin
   • Appkey: Click in the entry box and select the displayed value.
   • Bot: Select moderator-bot from the dropdown
   • Version: Click the dropdown. Select the displayed value.
   • Leave the other fields unchanged.
7. If the Channel Subscriptions section is collapsed, expand it, then enter the following values:
   • Channel-name: moderator-channel
   • Leave the other fields unchanged.
8. Click Save to save your work and return to the chat project info page.

Next, add the weather streambot:

1. From the chat project info page, click Bot instances in the tab bar.
2. Click Add a bot instance.
3. Enter the following values:
   • Bot name: weather-bot
   • Role: admin
   • Appkey: Click in the entry box and select the displayed value.
   • Bot: Select moderator-bot from the dropdown
   • Version: Click the dropdown. Select the displayed value.
   • Leave the other fields unchanged.
4. If the Channel Subscriptions section is collapsed, expand it, then enter the following values:
   • Channel-name: moderator-channel
   • Leave the other fields unchanged.
5. Click Save to save your work and return to the chat project info page.

After you add the streambot instances, Satori needs about 30 seconds to start them. When they're ready, their status on the chat project info page changes from Pending to Running. When the streambot instances are running, run the demo.

Run demo using the provided server

To run the demo using the server provided in the demo code:

1. Run the server

npm run start

This starts the local demo server, which uses port 3000. To chat with others:

1. Don't use the displayed link, because it just displays the URL for your local server. You need your server's IP address and channel information.
2. Instead, switch focus to the terminal app in which you started the server. A message lists the IP address of the server on your local network.
3. Copy the URL and send it to the users you want to chat with.

Run demo from your own server

To run the demo using your own server:

1. Build the demo for deployment

npm run build

1. Deploy the build to your server. All the necessary files are in the directory chat/build. The demo main page is in chat/build/index.html.

App architecture

The chat app uses the following Satori components:

• Satori JavaScript API
• Satori Open Channels
• Satori streambots
• Satori views
• Satori Key-Value Store.

As noted, it also uses the React Create App framework.

Moderator streambot (moderator)

This streambot is the controller for the chat app. It manages and stores metadata and publishes messages as needed.

channel-manager

Moderator uses the channel-manager channel to manage user metadata, enforce security, and communicate with streambots used by the app:

• User metadata: Moderator publishes messages about current chat users to channel-manager, and newly-joined app instances use the message data to get the current state of the chat.
• Security: To ensure that app instances can only read messages in rooms to which they were invited, apps are not allowed read access to channel-manager. Instead, app instances read from their chat room channel.
• Streambots: Moderator controls the weather streambot by publishing bot_message messages to channel-manager. When the weather streambot receives a bot_message, it retrieves data from the National Weather Service and publishes it to channel-manager.

Persistence

Because channels can't keep an infinite number of messages, moderator uses key-value storage to archive older channel-manager messages.

Presence emulation

App instances periodically post update_presence messages to channel-manager. Moderator processes and republishes these messages to a presence channel for the chat rooms. When users join the chat room, the app instance reads the presence channel to determine who is actively using the chat room.

Weather streambot

The chat room demo includes a streambot that delivers weather information in response to requests posted in a chat room. The bot subscribes to channel-manager and waits for bot_message messages that contain weather requests. When it receives one, it handles the request by applying a custom Satori view to the Satori National Weather Service Open Channel. The weather streambot then publishes its response to channel-manager. Moderator processes and republishes this message in the same way that it publishes chats between users.

Next steps

Try extending the demo to include more chat functionality and different streambots or views (or both).

You can embed this app in your apps or in other demo apps we offer.

Further reading

• Satori Developer Documentation: Documentation for the entire Satori Live Data Ecosystem
• Satori JavaScript SDK: The Satori JavaScript API and developer tools
• Satori JavaScript tutorial): Tutorial that shows you how to write JavaScript apps that use the SDK and the Satori Live Messaging platform