persisted

Meta type for marking stores or fields for opt-in persistence.

Signature

import { persisted } from 'storion/persist';

// Store-level - mark entire store for persistence
persisted()

// Field-level - mark specific fields for persistence
persisted.for('fieldName')
persisted.for(['field1', 'field2'])

Usage

The persisted meta works with persistedOnly: true option in persist() middleware. When opt-in mode is enabled, only stores/fields with persisted meta are persisted.

Store-Level Persistence

Mark the entire store for persistence:

import { store } from 'storion';
import { persisted } from 'storion/persist';

const userStore = store({
  name: 'user',
  state: { name: '', email: '', avatar: '' },
  meta: persisted(),  // All fields will be persisted
  setup: () => ({}),
});

Field-Level Persistence

Mark only specific fields for persistence:

import { store } from 'storion';
import { persisted } from 'storion/persist';

const settingsStore = store({
  name: 'settings',
  state: { 
    theme: 'light',      // Will be persisted
    fontSize: 14,        // Will be persisted
    cache: {},           // Will NOT be persisted
  },
  meta: persisted.for(['theme', 'fontSize']),
  setup: () => ({}),
});

Enable Opt-In Mode

The persisted meta only has effect when persistedOnly: true is set:

import { container, forStores } from 'storion';
import { persist, persisted } from 'storion/persist';

const app = container({
  middleware: forStores([
    persist({
      persistedOnly: true,  // Enable opt-in mode
      handler: (ctx) => ({
        load: () => JSON.parse(localStorage.getItem(ctx.displayName) || 'null'),
        save: (state) => localStorage.setItem(ctx.displayName, JSON.stringify(state)),
      }),
    }),
  ]),
});

Priority with notPersisted

When both persisted and notPersisted are present, notPersisted always takes priority:

import { persisted, notPersisted } from 'storion/persist';

const userStore = store({
  name: 'user',
  state: { name: '', password: '', token: '' },
  meta: meta.of(
    persisted(),                          // All fields opted in
    notPersisted.for(['password', 'token']), // But these are excluded
  ),
});
// Result: Only 'name' is persisted

Filtering priority (highest to lowest):

1. notPersisted — Always excludes
2. persistedOnly — Requires persisted meta
3. filter option — Custom filter function

When to Use

Scenario	Recommendation
Large app with many stores	Use persistedOnly: true + persisted
Most stores need persistence	Use default + notPersisted for exceptions
Security/compliance requirements	Use persistedOnly: true for explicit opt-in
Simple app	Use default mode (simpler)

See Also

• persist() - Persistence middleware
• notPersisted - Excluding from persistence
• Persistence Guide - Complete persistence guide