GoF Mediator

Mediator.js

class Bidder {
    constructor (name) {
        this.name = name;
        this.auction = null;
    }
    bid (amount, to) {
        this.auction.send(amount, this, to);
    }
    offer (amount, from) {
        console.log(from.name + " offered " + amount);
    }
}

class Auctioneer {
    constructor () {
        this.participants = {};
    }
    register (participant) {
        this.participants[participant.name] = participant;
        participant.auction = this;
    }
    send (amount, from, to) {                  // broadcast message
        for (let key in this.participants) {
            if (this.participants[key] !== from) {
                this.participants[key].offer(amount, from);
            }
        }
    }
};


const julie = new Bidder("Julie");
const annie = new Bidder("Annie");
const paul = new Bidder("Paul");

const auction = new Auctioneer();
auction.register(julie);
auction.register(annie);
auction.register(paul);

julie.bid(20);
julie.bid(10);

// Julie offered 20
// Julie offered 20
// Julie offered 10
// Julie offered 10