moleculer-socketio

Description

Manage socket.io's namespaces like services and actions.

Project example

You can find an example of moleculer-socketio and moleculer-nextjs at moleculer-nextjs-socketio-example

Install

$ npm install moleculer-socketio --save

USAGE

you 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")

Events

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.

Middlewares

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";    
            }
        }
        
    }
}

Custom response

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
			};
		},
	},
    
};

EXAMPLE

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);