How do I implement custom messages, just like websockets

[willjayyyy]

I have a requirement that the client only sends data to the server, and the server can freely choose who to push messages to, just like a native websocket. The purpose of doing so is to send authentication information to the server, and the server can return the permissions I have, such as read-only. I know this can be achieved using websocket, but I hope to directly access agent.custom during the authentication process and bind the permission information to it.

[alecgibson]

We're slightly hacking our way around this issue by piggy-backing the handshake message.

So on the server, we have some middleware:

backend.use('reply', ({reply, agent}) => {
  if (reply.a !== MESSAGE_ACTIONS.handshake) return;
  const auth = agent.custom;
  reply.$custom = {auth};
});

And then on the client, you can parse it out:

connection.on('receive', ({data}) => {
  if (data.a !== MESSAGE_ACTIONS.handshake) return;
  const {auth} = data.$custom;
  // do stuff with auth
});

[willjayyyy]

We're slightly hacking our way around this issue by piggy-backing the handshake message.

So on the server, we have some middleware:

backend.use('reply', ({reply, agent}) => {
  if (reply.a !== MESSAGE_ACTIONS.handshake) return;
  const auth = agent.custom;
  reply.$custom = {auth};
});

And then on the client, you can parse it out:

connection.on('receive', ({data}) => {
  if (data.a !== MESSAGE_ACTIONS.handshake) return;
  const {auth} = data.$custom;
  // do stuff with auth
});

Thank you for your reply, but there is still one issue. The client cannot independently request the server. In other words, I can only rely on other requests to attach relevant information, which is very inconvenient. I hope to be able to independently request the server like websocket, and the server can also push my customized information to the client separately

I have come up with a good way to bypass it, using presence to simulate API requests

const presence = connection.getPresence('api:auth')
const localPresence = presence.create(id)
localPresence.submit(data, result => {
 
})

and in server,I intercepted the presence at the beginning of the API and used callback to return it in an incorrect form

backend.use('receivePresence', (context, next) => {
  const {ch} = context
  if (/^api:/.test(ch)) {
    // do something
    return next(result)
  }
})

At this point, I can achieve functions similar to APIs, but the server actively pushes customized messages to the client, which I am still unable to achieve

A more compromise approach is to obtain the websocket instance in the context and use websocket for push