salt-lib

Simple dynamic frontend rendering library.

Install

npm install @royalsaltmerchant/salt-lib

Exports

import { Component, createElement } from "@royalsaltmerchant/salt-lib";

Core Model

• Component owns one domElem root.
• render() always clears first, then appends returned output.
• render() can be async.
• If multiple async renders overlap, stale older renders are dropped.
• Compose nested classes with useChild(key, factory, update?) or childElem(key, factory, update?).

Component API

Constructor

new Component({
  domElem,      // optional mount element
  tagName,      // optional root tag if domElem not provided (default: "div")
  className,    // optional class for root
  state,        // optional initial state object
  autoInit,     // default: true
  autoRender,   // default: true
})

Mount rules:

• If domElem is provided, it is used.
• If not, a detached root is created.
• salt-lib does not auto-query #app.

Lifecycle rules:

• autoInit defaults to true.
• autoRender defaults to true.
• If a render already started before constructor auto-render runs (manual constructor render or init() render), auto-render is skipped to avoid duplicate first paint.

Methods

• async init()
• async render()
• useMemo(key, factoryOrValue, depsOrFactory = [])
• clearMemo(key?)
• useChild(key, factory, update?)
• async childElem(key, factory, update?)
• dropChild(key, { destroy = true })
• clearChildren({ destroy = true })
• async setState(nextStateOrUpdater, { replace = false, render = true })
• getState()
• onCleanup(fn)
• offCleanup(fn)
• runCleanup()
• clear({ deep = false })
• destroy({ clear = true, clearMemo = true, destroyChildren = true })

useChild / childElem Pattern

useChild caches one child instance per key.

childElem is shorthand for: get cached child -> run child render -> return child.domElem.

import { Component, createElement } from "@royalsaltmerchant/salt-lib";

class CounterCard extends Component {
  render = async () => {
    return [
      createElement("article", { className: "card" }, [
        createElement("h2", {}, this.props.title),
        createElement("div", {}, String(this.props.count)),
      ]),
    ];
  };
}

class App extends Component {
  state = { count: 0, title: "Counter" };

  increment = async () => {
    await this.setState((prev) => ({ count: prev.count + 1 }));
  };

  renderCounterCard = async () => {
    return this.childElem(
      "counter-card",
      () =>
        new CounterCard({
          domElem: createElement("div"),
          autoInit: false,
          autoRender: false,
          title: this.state.title,
          count: this.state.count,
        }),
      (child) => {
        child.props.title = this.state.title;
        child.props.count = this.state.count;
      },
    );
  };

  render = async () => {
    const cardElem = await this.renderCounterCard();

    return [
      createElement("h1", {}, "salt-lib"),
      createElement(
        "button",
        { type: "button" },
        "+1",
        { type: "click", event: this.increment },
      ),
      cardElem,
    ];
  };
}

const root = document.getElementById("app");
if (!root) throw new Error("Missing #app");

new App({ domElem: root });

createElement API

createElement(tag, attributes, children, eventListeners, options)

Attributes

• className maps to class.
• style supports object syntax.
• dataset supports object syntax.
• Boolean attrs follow HTML boolean semantics.

Children

• Supports single child or nested arrays.
• Supports Node, string, number, and other primitives.
• null, undefined, and false are skipped.

Event listeners

• Accepts one listener object or an array.

{ type: "click", event: handler, options: { once: true } }

Raw HTML (opt-in)

createElement("div", {}, "<b>trusted html</b>", null, { allowHtml: true });

Render Output Types

A render() return value can include:

• DOM nodes
• nested arrays of nodes
• strings / numbers
• component instances (their domElem is appended)

Example App In Repo

Files:

• examples/memo-child-state/index.html
• examples/memo-child-state/main.js
• examples/memo-child-state/style.css

Run:

python3 -m http.server 4173

Open:

http://localhost:4173/examples/memo-child-state/

Publish Checklist

1. Set package metadata in package.json:
   • repository
   • bugs
   • homepage
2. Run local validation:

npm test
npm run pack:check

3. Publish:

npm login
npm publish