Counter

The “hello world” of Triggery. Two buttons fire an increment/decrement event; a counter component reacts via useAction and re-renders itself. Nothing more.

Open in StackBlitz Open example on GitHub

File layout

• README.md narrative overview
• index.html Vite entry
• Directorysrc/

  • App.tsx producers + reactors live here
  • main.tsx bootstrap
  • Directorytriggers/

    • notification.trigger.ts the rule

The trigger

src/triggers/counter.trigger.ts

import { createTrigger } from '@triggery/core';

export const counterTrigger = createTrigger<{
  events:  { increment: void; decrement: void };
  actions: { adjust: number };
}>({
  id: 'counter',
  events: ['increment', 'decrement'],
  handler({ event, actions }) {
    actions.adjust?.(event.name === 'increment' ? 1 : -1);
  },
});

The components

src/Counter.tsx

import { useAction, useEvent } from '@triggery/react';
import { useState } from 'react';
import { counterTrigger } from './triggers/counter.trigger';

export function Counter() {
  const [count, setCount] = useState(0);

  const inc = useEvent(counterTrigger, 'increment');
  const dec = useEvent(counterTrigger, 'decrement');

  useAction(counterTrigger, 'adjust', delta => setCount(c => c + delta));

  return (
    <div>
      <button onClick={() => dec()}>−</button>
      <output>{count}</output>
      <button onClick={() => inc()}>+</button>
    </div>
  );
}

That’s the whole thing. The producer and reactor happen to live in the same component, but they could be split — the wiring stays the same. See Notification pipeline for a scenario where they really must split.

Related

Notification pipeline The same shape, but with three reactors in three components.

Same recipe — Solid With Solid's createSignal.

Same recipe — Vue Composition API version.

Anatomy of a trigger The createTrigger config in full.