⚡ spark-html-persist

Persist a spark-html store across reloads — one line. Hydrates from storage on boot, saves on every change. Built on store() + subscribe(), one dependency.

import { persist } from 'spark-html-persist';

// a normal store(), but it survives reloads:
persist('settings', { theme: 'dark', fontSize: 14 });

<!-- any component -->
<script>const s = useStore('settings');</script>
<button onclick="{s.theme = s.theme === 'dark' ? 'light' : 'dark'}">{s.theme}</button>

Change s.theme, reload the page — it's still there.

Install

bun add spark-html-persist

API

persist(name, initial?, options?)

Returns the same store as store(name) — useStore(name) reads it everywhere. Saved values layer on top of initial, so adding a new default key works even for users with an older saved blob.

| Option | Default | Meaning | |--------|---------|---------| | key | spark:<name> | Storage key. | | storage | localStorage | Any Storage — pass sessionStorage for per-tab state. | | include | all keys | Persist only these keys. | | exclude | — | Persist everything except these keys. |

persist('user', { name: '', token: '', draft: '' }, {
  storage: sessionStorage,
  exclude: ['token'],   // keep secrets out of storage
});

Writes are coalesced to one setItem per tick, and storage errors (quota, private mode, corrupt JSON) fall back silently to the defaults — never throws.

The Spark family

Small, single-purpose packages that share one philosophy: no compiler, no virtual DOM, no build step required — built for humans who love hand-writing their web apps. Add only what you use.

| Package | What it does | |---|---| | spark-html | The runtime — components, reactivity, stores, forms, scoped styles. ~14.4 kB gzip, 0 deps. | | spark-html-bun | Dev server, bundler & preview on Bun — scoped HMR, no-build dev, post-build pipeline. | | spark-html-router | <template route> routing — nested routes/layouts, route.query, active links. | | spark-html-theme | Dark/light/system theming in one line — persisted, no flash. | | spark-html-head | Reactive <title>/<meta> per route + a head store. | | spark-html-motion | Enter/leave transitions on if/each blocks — transition="fade|slide|scale". | | spark-html-devtools | In-page devtools — live stores, component tree, patch activity. | | spark-html-query | Declarative async data — a self-fetching store (loading/error/data/refetch). | | spark-html-persist | Persist stores to localStorage/sessionStorage in one line. | | spark-html-websocket | A WebSocket as a reactive store — auto-reconnect, JSON, send(). | | spark-prerender | Build-time SEO prerender + sitemap/robots — no SSR server. | | spark-ssr | Full-stack SSR on Bun — the template is the backend: inferred DB, REST CRUD, auth, live updates. Precompiled + response-cached: fast by default. | | spark-html-image | Build-time image optimization — webp/avif + responsive srcset, zero config. | | spark-html-font | Font loading optimizer — preload + size-adjusted fallbacks, no FOUT. | | spark-html-manifest | PWA manifest + icons + head tags (and optional service worker) from one config. | | spark-html-offline | Offline URL imports — a service worker that caches CDN components. | | spark-html-sri | Subresource Integrity — hash + verify assets and remote components. | | create-spark-html-app | Scaffold a spark-html app in one command. | | prettier-plugin-spark | Prettier for components — formats <script>/<style>, markup stays byte-for-byte. | | spark-html-language-server | LSP — diagnostics, go-to-definition, prop autocomplete, hover docs. |