events

// Basic event listener
const button = document.getElementById('myButton');

button.addEventListener('click', function(event) {
  console.log('Button clicked!');
  console.log('Event type:', event.type);

-- Publisher: Send notification
NOTIFY new_order, 'Order #12345 created';

-- Subscriber: Listen for notifications
LISTEN new_order;

<?php

namespace App\Observers;

use App\Events\PostPublished;
use App\Models\Post;

from django.db.models.signals import post_save
from django.dispatch import receiver
from django.core.mail import send_mail
from .models import User, Profile

export type EventMap = Record<string, unknown[]>;

type Listener<Args extends unknown[]> = (...args: Args) => void;

export class TypedEmitter<Events extends EventMap> {
  private listeners = new Map<keyof Events, Set<Listener<any>>>();

package events

import "encoding/json"

type Envelope struct {
  Type    string          `json:"type"`

<?php

namespace App\Events;

use App\Models\Order;
use Illuminate\Broadcasting\PrivateChannel;

export interface AnalyticsEvent {
  name: string;
  props?: Record<string, unknown>;
  ts: number;
}

<?php

namespace App\Providers;

use App\Events\OrderPlaced;
use App\Listeners\DecrementInventory;

package com.example.demo.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.context.annotation.Bean;

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Builder;

import { RefObject, useEffect, useRef } from "react";

type Handler = (event: MouseEvent | TouchEvent) => void;

export function useClickOutside<T extends HTMLElement>(
  ref: RefObject<T>,