websockets-client-v7.go

// writeMessages is a process that listens for new messages to output to the Client
func (c *Client) writeMessages() {
	// Create a ticker that triggers a ping at given interval
	ticker := time.NewTicker(pingInterval)
	defer func() {
		ticker.Stop()
		// Graceful close if this triggers a closing
		c.manager.removeClient(c)
	}()

	for {
		select {
		case message, ok := <-c.egress:
			// Ok will be false Incase the egress channel is closed
			if !ok {
				// Manager has closed this connection channel, so communicate that to frontend
				if err := c.connection.WriteMessage(websocket.CloseMessage, nil); err != nil {
					// Log that the connection is closed and the reason
					log.Println("connection closed: ", err)
				}
				// Return to close the goroutine
				return
			}

			data, err := json.Marshal(message)
			if err != nil {
				log.Println(err)
				return // closes the connection, should we really
			}
			// Write a Regular text message to the connection
			if err := c.connection.WriteMessage(websocket.TextMessage, data); err != nil {
				log.Println(err)
			}
			log.Println("sent message")
		case <-ticker.C:
			log.Println("ping")
			// Send the Ping
			if err := c.connection.WriteMessage(websocket.PingMessage, []byte{}); err != nil {
				log.Println("writemsg: ", err)
				return // return to break this goroutine triggeing cleanup
			}
		}

	}
}