Message

Core structure and usage methods of WuKongIM messages

Concept Explanation

What is a Message?

A Message is the basic unit of information transmission in WuKongIM, serving as the carrier for real-time communication between users. Each message contains information about the sender, receiver, content, and metadata.

Why are Messages Important?

• Communication Foundation: Messages are the core of instant messaging systems; all chat functionality is based on message transmission
• Data Carrier: Messages can transmit not only text but also various types of data like images, files, and locations
• Status Tracking: Each message has a unique identifier and status, making it easy to track message sending, receiving, and read status

Relationship with Other Concepts

• Channel: Messages are transmitted through channels, which define the message destination
• User: Messages have clear senders and receivers, all of whom are users in the system
• Conversation: Messages update corresponding conversation records, affecting conversation list display

Core Structure

Messages contain the following core attributes:

Attribute	Type	Description
message_id	integer	Message unique identifier
message_seq	integer	Message sequence number within channel
client_msg_no	string	Client message identifier
from_uid	string	Sender user ID
channel_id	string	Target channel ID
channel_type	integer	Channel type (1=personal, 2=group)
timestamp	integer	Message timestamp
payload	string	Base64 encoded message content

Message Example

{
  "message_id": 123456789,
  "message_seq": 1001,
  "client_msg_no": "client_msg_123",
  "from_uid": "user123",
  "channel_id": "group123",
  "channel_type": 2,
  "timestamp": 1640995200,
  "payload": "SGVsbG8gV29ybGQ="
}

Related API Endpoints

Endpoint	Method	Description
/message/send	POST	Send single message
/message/sendbatch	POST	Send batch messages
/message/search	POST	Search historical messages
/channel/messagesync	POST	Sync channel messages

EasySDK Code Examples

Send Messages

Web

import { WKIM, WKIMChannelType } from 'easyjssdk';

// Initialize SDK
const im = WKIM.init("ws://your-server.com:5200", {
  uid: "your_user_id",
  token: "your_token"
});

// Send text message
const textPayload = {
  type: 1,
  content: "Hello, World!"
};
const result = await im.send("friend_user_id", WKIMChannelType.Person, textPayload);

// Send image message
const imagePayload = {
  type: 2,
  url: "https://example.com/image.jpg",
  width: 800,
  height: 600
};
const imageResult = await im.send("group_id", WKIMChannelType.Group, imagePayload);

Listen for Messages

Web

import { WKIMEvent } from 'easyjssdk';

// Listen for new messages
im.on(WKIMEvent.Message, (message) => {
  console.log("Received new message:", message);
  console.log("Message content:", message.payload);
  console.log("Sender:", message.fromUid);
});

Message Type Handling

Web

// Handle different content based on message type
im.on(WKIMEvent.Message, (message) => {
  const payload = JSON.parse(message.payload);

  switch (payload.type) {
    case 1: // Text message
      console.log("Text message:", payload.content);
      break;
    case 2: // Image message
      console.log("Image message:", payload.url);
      break;
    case 100: // Custom message
      console.log("Custom message:", payload);
      break;
  }
});

The message content payload field uses Base64 encoding, with the specific format defined by the application layer.