Smart Device Client - WebSocket Protocol Help

Overview

The Smart Device Client uses a WebSocket-based protocol powered by Socket.IO to facilitate real-time communication between devices in a meeting. This document describes the connection process, supported events, and command formats.

Connection

Clients connect to the server using Socket.IO at the /io namespace. The connection requires two query parameters:

meetId (string): The unique identifier for the meeting room.
email (string): The client's email address for identification.

Example connection (JavaScript):

const socket = io('/io', {
  query: { meetId: 'room1', email: 'user1@example.com' }
});

Events

Server-to-Client Events

Event	Description	Payload
`connect`	Triggered when the client successfully connects to the server.	None
`connectionError`	Triggered if the connection fails (e.g., missing query parameters).	{ message: string }
`deviceConnected`	Triggered when a device joins the meeting.	{ deviceId: string, email: string, meetId: string, totalDevices: number }
`deviceDisconnected`	Triggered when a device leaves the meeting.	{ deviceId: string, email: string, meetId: string, totalDevices: number }
`deviceMessage`	Triggered when a device broadcasts a message.	{ senderId: string, senderEmail: string, message: string, timestamp: string }
`control`	Triggered when a control command is received.	{ senderId: string, senderEmail: string, command: string, data?: any, timestamp: string }
`controlError`	Triggered if a control command fails (e.g., invalid JSON).	{ message: string }
`deviceList`	Triggered in response to `getDeviceList`, listing all connected devices.	{ devices: [{ id: string, email: string }], total: number, meetId: string }

Client-to-Server Events

Event	Description	Payload
`getDeviceList`	Requests the list of connected devices in the meeting.	None
`broadcast`	Sends a message to all devices in the meeting.	string
`control`	Sends a control command to a specific device.	{ targetEmail: string, command: string, data?: any }

Control Command Format

Control commands sent via the control event must include:

targetEmail (string): The email of the target device.
command (string): The command name (e.g., mute, pause, custom).
data (optional, any): Additional data in valid JSON format.

Example valid control command:

socket.emit('control', {
  targetEmail: 'user2@example.com',
  command: 'custom',
  data: { command: 'stop' }
});

Invalid JSON in data (e.g., {command:"stop"}) will trigger a controlError event.

Usage Notes

Ensure meetId and email are provided during connection.
Use the web interface at / to join meetings, send broadcasts, and issue control commands.
Control commands require valid JSON in the data field to avoid errors.
Monitor the message list for real-time updates on connections, messages, and control events.