@triggery/signals

Read a signal from a Triggery condition without engaging signal-tracking on the host component. Compatible with @preact/signals-core, alien-signals, and any structurally-similar signal exposing peek() or .value.

Install

pnpm

pnpm add @triggery/core @triggery/react @triggery/signals @preact/signals-core

npm

npm install @triggery/core @triggery/react @triggery/signals @preact/signals-core

yarn

yarn add @triggery/core @triggery/react @triggery/signals @preact/signals-core

bun

bun add @triggery/core @triggery/react @triggery/signals @preact/signals-core

Peer deps: react >= 18.0.0. The signals library is your choice — @preact/signals-core and alien-signals both work.

What’s inside

Export	Purpose
useSignalCondition(trigger, name, signal, selector?)	Register a signal-backed condition. Prefers peek(), falls back to .value.

Quick example

import { signal } from '@preact/signals-core';
import { createTrigger } from '@triggery/core';
import { useSignalCondition } from '@triggery/signals';

const settings = signal({ sound: true, notifications: true });

const messageTrigger = createTrigger<{
  events: { 'new-message': { text: string } };
  conditions: { settings: { sound: boolean; notifications: boolean } };
  actions: { showToast: { body: string } };
}>({
  id: 'message-received',
  events: ['new-message'],
  required: ['settings'],
  handler({ event, conditions, actions }) {
    if (!conditions.settings.notifications) return;
    actions.showToast?.({ body: event.payload.text });
  },
});

function SettingsBridge() {
  useSignalCondition(messageTrigger, 'settings', settings);
  return null;
}

With a projection selector:

useSignalCondition(messageTrigger, 'settings', profile, (p) => p.settings);

How it works

Pull-only: the signal is read only when a trigger fires. The adapter prefers peek() (no dependency tracking) and falls back to .value if peek is missing. Either way, no subscriber is registered against the signal, so the host component never re-renders on signal updates.

If a component also needs to render the signal, use useSignal() from @preact/signals-react or the equivalent in your signal library — the two paths are orthogonal.

API

useSignalCondition<V, S, K>(
  trigger: Trigger<S>,
  name: K,
  signal: { peek?(): V; readonly value?: V },
  selector?: (value: V) => ConditionMap<S>[K],
): void

Related packages

@triggery/core Exposes Trigger.

@triggery/react useSignalCondition is a React hook.

@triggery/reatom Alternative adapter for Reatom atoms.

@triggery/jotai Alternative adapter for Jotai atoms.

@triggery/mobx Alternative adapter for MobX observables.

Source

• GitHub
• npm
• Changelog