I am using moleculerjs to handle microservices on the backend, and with one of the front-end applications I am handling the communication over sockets. To do that I am using moleculer.io. The problem I'm running into is that, even though I am attaching the socket to ctx in the onBeforeCall() hook, the socket is not there when I console.log ctx in the controller function.
My gateway looks like this (notice the socket is being added to the ctx object in the onBeforeCall() hook:
const SocketIOService = require("moleculer-io");
module.exports = {
name: 'oas',
mixins: [SocketIOService],
settings: {
port: 5000,
io: {
namespaces: {
'/': {
events: {
'call': {
aliases: {
'auth.register': 'oas.controllers.auth.register'
},
whitelist: [
'**',
],
onBeforeCall: async function(ctx, socket, action, params, callOptions) { // before hook
console.log('socket: ', socket); // This exists here
ctx.socket = socket; // Here I attach the socket to the ctx object
},
onAfterCall: async function(ctx, socket, res) { // after hook
// console.log('after hook', res)
// res: The response data.
}
}
}
}
}
},
events: {},
actions: {}
}
};
And my auth.service looks like this - notice the register() function that tries to access ctx.socket:
"use strict";
/**
* @typedef {import('moleculer').Context} Context Moleculer's Context
*/
module.exports = {
name: "oas.controllers.auth",
/**
* Settings
*/
settings: {
},
/**
* Dependencies
*/
dependencies: [],
/**
* Actions
*/
actions: {
async register(ctx) {
console.log('ctx.socket: ', ctx.socket); // This is undefined
// Other code...
},
/**
* Events
*/
events: {
},
/**
* Methods
*/
methods: {
},
/**
* Service created lifecycle event handler
*/
created() {
},
/**
* Service started lifecycle event handler
*/
async started() {
},
/**
* Service stopped lifecycle event handler
*/
async stopped() {
}
};
Here in the register() function that gets called, ctx.socket is undefined. What am I missing here? I assume that onBeforeCall() is designed to be used for exactly this kind of purpose, but perhaps I'm misunderstanding something.
Is there a different way I should or could approach this to ensure the socket is available in the called function? And just to clarify, the socket is available in the onBeforeCall() hook. I need to figure out how to make it available down the line.
In the end I found a way to do this. Instead of attaching the socket to ctx directly, which as @Icebob pointed out, you can't do, I was able to attach it ctx.meta, like so:
onBeforeCall: async function(ctx, socket, action, params, callOptions) { // before hook
ctx.meta.socket = socket;
},
By doing this I was able to successfully access the socket in my register() function.