Manage socket.io's namespaces like services and actions.
You can find an example of moleculer-socketio and moleculer-nextjs at moleculer-nextjs-socketio-example
$ npm install moleculer-socketio --saveyou can use moleculer-socketio manage events like actions in services, in socket.io it's called namespaces so you must add it into your service.
In socket.io, the root channel is / but you can define multiple namespaces !
namespaces: {
"/": {
// root namespace
hello(ctx) {
this.logger.info("Hello there");
return "Get this data!";
}
},
"/private": {
// another namespace
hi(ctx) {
this.logger.info("You're not the droid I'm looking for.")
}
}
}On the client side you could connect to those namespaces :
const io = require("socket.io-client");
const root = io("http://ip:port");
root.emit("hello");
root.on("hello", (data) => {
console.log("hello return", data);
});
const private = io("http://ip:port/private");
private.emit("hi")Every events for each namespaces can be code differently :
namespaces: {
"/": {
eventA(ctx) {
return "somedata"
},
eventB: {
// You can specify parameter validation
// Just like actions
params: {
parameterA: "string",
parameterB: "number"
},
async handler(ctx) {
return "somedata again";
}
},
eventC: "service.action",
eventD: [
"service.action",
function(ctx) {
return "another data"
},
"service.action"
]
}
}When you return data from an event, it will emit an event with it.
You may want to add some conditions to validate the execution of your actions. You can use a middleware for this case.
namespaces: {
"/private": {
middlewares: [
function(ctx) {
if (!ctx.params.crypted) {
throw new Error("You're missing crypted parameter");
}
}
],
deleteAllUsers: {
middlewares: [
function(ctx) {
if (!ctx.params.isAdmin) {
throw new Error("No, you're not an admin");
}
},
function(ctx) {
if (ctx.params.username != "Icebob") {
throw new Error("Sorry, you're not enough badass");
}
}
],
handler(ctx) {
return "Destroy everything";
}
}
}
}One more thing, you can also manage custom responses.
const SocketIO = require("moleculer-socketio");
module.exports = {
name: "socket-service",
mixins: [ SocketIO ],
settings: {
port: 5000,
options: {
// Socket.io options
},
response: (event, error, results) => {
// Response Templated
let payload = {};
if (!error) {
if (results.length > 1) {
results.map((r, index) => {
payload[event.actions[index]] = r;
});
} else {
payload = results[0];
}
}
return {
error: error,
payload: payload
};
},
},
};const SocketIO = require("moleculer-socketio");
module.exports = {
name: "socket-service",
mixins: [ SocketIO ],
settings: {
port: 5000,
options: {
// Socket.io options
},
},
actions: {
},
namespaces: {
"/": {
connection(ctx) {
this.logger.info("Someone is connected");
ctx.socket.emit("hello", "Welcome to socket.io");
},
sendMessage: {
params: {
message: "string"
},
async handler(ctx) {
this.logger.info(ctx.params.message);
return true;
}
},
},
"/admin": {
middlewares: [
function(ctx) {
if (!ctx.params.isAdmin) {
throw new Error("Sorry you can't connect here");
}
}
],
connection: {
middlewares: [
function(ctx) {
if (ctx.params.isAdmin && ctx.) {
throw new Error("Sorry you can't connect here");
}
}
],
async handler(ctx) {
this.logger.info("An administrator is connected");
ctx.socket.emit("hello", "Welcome to socket.io on admin side");
}
}
}
},
methods: {
onCreated(io) {
console.log("socket-io.service - onCreated");
this.io = io;
this.io.on("oldWay", (socket, data) => {
this.logger.info("oldWay - ", data);
socket.emit("oldWay", "You can still to this");
});
},
},
}This should be on client side
import io from 'socket.io-client';
this.socket = io("http://localhost:5000");
this.socket.on("all", (data) => {
console.log("client -- ", data);
});
this.socket.on('timer', timestamp => console.log("TIMER IS", timestamp));
this.socket.emit('subscribeToTimer', 1000);