Broadcasting messages to WebSocket API clients

Invoking individual WebSocket connections has been supported since Zato 3.0 and Zato 3.1 adds new functionality on top of it - message broadcasting - which lets one notify all the clients connected to a particular channel. Here is how to use it.


Let's say that there is a WebSocket channel such as the one here:

In the context of broadcast messages, the most important part of this definition is its name - below, we will be sending messages to all clients connected to that particular channel by its name.

Python code

# -*- coding: utf-8 -*-

from __future__ import absolute_import, division, print_function, unicode_literals

# Zato
from zato.server.service import Service

class WSXBroadcast(Service):

    def handle(self):

        # Channel to invoke
        name = 'My WSX API Channel'

        # Get a handle to the channel object
        channel =[name]

        # Message to send
        data = 'Hello from Zato'

        # Broadcast this message to all clients connected to that channel

And this is literally it - you have just broadcast a message to all WebSocket connections of that channel. It does not matter if clients are in JavaScript, Python, if they are other Zato servers or browsers - all of them receive the notification.

Note that the messages are always sent in background - they are treated as asynchronous messages and Zato does not wait for any potential response from the clients.