observer-ax/src/main/bus/EventConcreteBus.ts

Patrón observable, event Bus.

import { EventBus } from './EventBus';
import { NotifyObject } from '../models/NotifyObject.model';
import { ReceiverBus } from './Receiver';
import { ItemBus } from '../models/Item.model';

export class EventConcreteBus implements EventBus {

    private _receivers: { [key: string]: ReceiverBus[] } = {};
    private _items: ItemBus[] = [];

    constructor(private defaultTriesCount: number = 3) { }

    protected getTopicReceivers(topic: string = 'ALL'): ReceiverBus[] {
        if (!this._receivers[topic]) {
            return [];
        }
        return this._receivers[topic];
    }

    protected retryPublish(topic: string, subject: NotifyObject, receiver: ReceiverBus, tries: number) {
        for (var i = 0; i < tries; i++) {
            try {
                receiver.receive(subject, { topic: topic, pendingItems: this._items.length });
                break;
            } catch (error) {
                console.error(error);
            }
        }
    }

    public async publish(subject: NotifyObject, topic: string = 'ALL', tries: number = 0): Promise<void> {
        if (tries === 0) {
            tries = this.defaultTriesCount;
        }
        const receivers = this.getTopicReceivers(topic);
        receivers.map((receiver: ReceiverBus) => new Promise(resolve => resolve(this.retryPublish(topic, subject, receiver, tries))),);
    }

    public async publishNow(): Promise<void> {
        while (this._items.length > 0) {
            const item = this._items.shift() as ItemBus;
            const receivers = this.getTopicReceivers(item.topic);
            if (receivers.length > 0) {
                receivers.map((receiver: ReceiverBus) =>
                    new Promise(resolve =>
                        resolve(this.retryPublish(item.topic, item.data, receiver, item.tries))));
            }
        }
    }

    public subscribe(receiver: ReceiverBus, topic: string = 'ALL') {
        if (!this._receivers[topic]) {
            this._receivers[topic] = [];
        }
        this._receivers[topic].push(receiver);
    }

    public unsubscribe(receiver: ReceiverBus, topic: string = 'ALL') {
        if (!this._receivers[topic]) {
            return;
        }
        this._receivers[topic] = this._receivers[topic].filter(item => item !== receiver);
    }

    get receivers(): any {
        return this._receivers;
    }

    set items(values: ItemBus[]) {
        this._items.push(...values);
    }
}