EffectsCopy Anchor Link

createFormEffect(api, selector, callback)Copy Anchor Link

Observes a form, field, or array API. The selector receives its store state; the callback receives the inferred selected value. Returns void and unsubscribes when its Solid owner disposes.

Selections compare deeply. The callback skips the initial selection and runs only on later changes that are not deeply equal. Unrelated state changes do not invoke it. This differs from createSubscribe, which compares selections with Object.is.

import { createField, createForm, createFormEffect } from '@oxform/solid';
import { z } from 'zod';

function EmailAudit() {
  const form = createForm({ schema: z.object({ email: z.string() }), defaultValues: { email: '' } });
  const email = createField({ form, name: 'email' });
  createFormEffect(
    email,
    state => state.value,
    value => {
      console.info(value);
    },
  );
  return <input aria-label='Email' {...email.props} />;
}

Supply an API accessor to follow changing instances. Switching the API or a field's binding releases the previous subscription and establishes a new baseline without invoking the callback.

Callbacks run untracked, so reactive reads in the callback do not add Solid dependencies. They may return Promise<void>, but the effect does not await completion or cancel previous callbacks. Server rendering runs no form effects.

Solid Version and TimingCopy Anchor Link

The Solid 1 entry delegates to core's effect subscription. The Solid 2 entry, @oxform/solid/v2, applies callbacks during Solid's effect application phase. Writes within one flush coalesce into the committed selection, so intermediate core values may never reach the callback. Switching the observed API establishes a new baseline in both versions.

See the Solid 2 guide for a timing example.

Use the core equivalent, createEffect, when you need to observe every selected core transition. It returns a subscription for callers to unsubscribe manually; see Core.