发布/订阅操作 | Fern Documentation

AsyncAPI 中的操作定义在 operations 键下，通道定义在 channels 键下。以下是定义发布和订阅操作的示例：

asyncapi.yml

channels:
  user/notifications:
    address: user/notifications
    messages:
      UserNotification:
        $ref: '#/components/messages/UserNotification'
operations:
  onUserNotification:
    action: receive
    channel:
      $ref: '#/channels/user~1notifications'
    summary: Receive user notifications
    description: Subscribe to user notification events
  sendUserNotification:
    action: send
    channel:
      $ref: '#/channels/user~1notifications'
    summary: Send user notification
    description: Publish a user notification event

消息示例

您可以通过在消息定义中使用 examples 键来提供消息示例：

asyncapi.yml

components:
  messages:
    UserNotification:
      name: UserNotification
      title: User Notification
      summary: Notification sent to a user
      contentType: application/json
      payload:
        $ref: '#/components/schemas/Notification'
      examples:
        - name: EmailNotification
          summary: Example email notification
          payload:
            userId: "123e4567-e89b-12d3-a456-426614174000"
            type: "email"
            message: "Welcome to our service!"
            priority: "medium"

发布操作

发布操作表示您的服务发送到通道的消息：

asyncapi.yml

operations:
  publishOrderStatus:
    action: send
    channel:
      $ref: '#/channels/order~1status'
    summary: Publish order status update
    description: Send order status updates to subscribers
    message:
      $ref: '#/components/messages/OrderStatus'

订阅操作

订阅操作表示您的服务从通道接收的消息：

asyncapi.yml

operations:
  subscribeToUserSignups:
    action: receive
    channel:
      $ref: '#/channels/user~1signup'
    summary: Subscribe to user signups
    description: Receive notifications when users sign up
    message:
      $ref: '#/components/messages/UserSignup'

双向通信

您可以为同一个通道定义发布和订阅操作，以启用双向通信：

asyncapi.yml

operations:
  sendChatMessage:
    action: send
    channel:
      $ref: '#/channels/chat~1room'
    summary: Send chat message
    description: Send a message to a chat room
  receiveChatMessage:
    action: receive
    channel:
      $ref: '#/channels/chat~1room'
    summary: Receive chat message
    description: Receive messages from a chat room