Segify

A lightweight, compiler that transforms vanilla HTML into interactive and dependency-free JavaScript modules.

Features

• ⚡ Super fast compilation
• 🎯 Simple syntax with reactive $ state
• 📦 Works with Vite out of the box

Quick Start

Installation

npm i --save-dev segify

Or try it out in the REPL.

Basic Example

<!-- counter.html -->
<script>
  $.count = 0;

  function increment() {
    $.count += 1;
  }
</script>

<div>
  <p>Count: {{ $.count }}</p>
  <button $onclick="increment">Add</button>
</div>

import Counter from './counter.html';

const app = new Counter({});
app.render(document.body);

Try this example in the REPL

Documentation

State Management

Segify uses the special $ object for reactive state management:

<script>
  // Reactive state
  $.user = {
    name: 'John',
    age: 25,
  };

  // Updates will trigger re-renders
  function updateName(newName) {
    $.user.name = newName;
  }
</script>

<div>
  <h2>{{ $.user.name }}</h2>
  <p>Age: {{ $.user.age }}</p>
</div>

Component Props

Components can receive props from their parent:

<!-- UserCard.html -->
<div class="user-card">
  <h3>{{ $.name }}</h3>
  <p>{{ $.role }}</p>
  <div class="content">{{ $.children }}</div>
</div>

<!-- App.html -->
<script>
  import UserCard from './UserCard.seg';
</script>

<UserCard name="Alice" role="Developer">
  <p>Custom content goes here</p>
</UserCard>

Performance Optimization

Use @const for non-reactive content:

<script>
  $.staticData = "This won't change";
  $.dynamicData = 'This will update';
</script>

<!-- Won't trigger re-renders -->
<h1>{{ @const $.staticData }}</h1>

<!-- Will update when $.dynamicData changes -->
<p>{{ $.dynamicData }}</p>

API Reference

Compiler API

compile(source: string, options?: CompileOptions): Promise<string>

Compiles HTML source into a JavaScript module.

import { compile } from 'segify';

const js = await compile(`
  <script>
    $.message = 'Hello';
  </script>
  <h1>{{ $.message }}</h1>
`);

Options:

• keepComments?: boolean - Preserve HTML comments
• filename?: string - Source filename for better error messages
• sourceMap?: boolean - Generate source maps

parse(source: string, options?: ParseOptions)

Parses HTML into an AST (Abstract Syntax Tree).

import { parse } from 'segify';

const { ast, data } = parse('<div>Hello</div>');

Vite Plugin

// vite.config.ts
import { defineConfig } from 'vite';
import { Segify } from 'vite-plugin-segify';

export default defineConfig({
  plugins: [
    Segify({
      extension: '.seg',
      asset: {
        raw: undefined,
        location: undefined,
      },
    }),
  ],
});

TypeScript Support

Add type definitions for your components:

// vite-env.d.ts
declare module '*.seg' {
  class Component {
    constructor(props: Record<string, any>);
    render(parent: HTMLElement): void;
  }
  export { Component, Component as default };
}

License

MIT