godprotocol/virtual_machine/Objects/Events.js

A distributed computing environment for Web 4.0 — integrating AI, decentralisation, and virtual computation.

import { query_ } from "../callables/functions/query.js";

class Events {
  constructor() {
    this.events_listeners = new Object();
  }

  add_listener = async (name, handler, filter) => {
    let listeners = this.events_listeners[name];
    if (!listeners) {
      listeners = new Array();
      this.events_listeners[name] = listeners;
    }
    if (
      !listeners.find(
        (li) =>
          li.handler === handler &&
          JSON.stringify(li.filter) === JSON.stringify(filter)
      )
    )
      listeners.push({ handler, filter });
  };

  emit = async (name, payload, cb) => {
    let listeners = this.events_listeners[name];
    if (!listeners) return;

    let total = 0;
    for (let l = 0; l < listeners.length; l++) {
      let { filter, handler } = listeners[l];

      if (await query_(payload, filter, await this.ds.get_folder())) {
        total++;
        handler(payload)
          .then((res) => {
            total--;
            cb && cb(res, { done: !total, event: { name, handler, filter } });
          })
          .catch((e) => {
            console.log(e.message);
          });
      }
    }
  };
}

export default Events;