html-jsx: Typed HTML templates using JSX

Generate static HTML from JSX/TSX templates. The perfect solution to server side rendering of HTML, more performant than template engines with type checking for HTML.

Why use html-jsx?

• Faster than traditional template engines since most of the work is done by the TypeScript compiler.
• Type checking for HTML using type definitions generated from the WHATWG Living Standard.
• It's secure. Escaping of tag contents and attributes to avoid XSS attacks.
• Validation of HTML structure using WHATWG content categories.

Getting started

Add the package as a dev dependency

npm add -D @triptease/html-jsx

Add the JSX configuration into the compiler options in tsconfig.json

{
  "compilerOptions": {
    "jsx": "react-jsx",
    "jsxImportSource": "@triptease/html-jsx"
  }
}

Write your templates using JSX/TSX, no imports required.

function greet(name: string) {
  return (
    <div>
      <p>
        Hello ${name}
      </p>
    </div>
  );
}

Features

HTML Type safety

Invalid HTML elements are caught at compile time

<h7></h7>

// TS2339: Property h7 does not exist on type JSX.IntrinsicElements

Invalid HTML attributes are caught at compile time

<div classs="my-class"></div>

// TS2322: Type { classs: string; } is not assignable to type HtmlTagDiv
// Property 'classs' does not exist on type HtmlTagDiv. Did you mean 'class'?

HTML attributes are type-checked

<input required="falsey"></input>

// TS2820: Type 'falsey' is not assignable to type BooleanAttribute | undefined. Did you mean 'false'?

Structural HTML validation

Validation of HTML structure using the WHATWG content categories is applied at runtime when NODE_ENV is set to development.

<span>
  <div></div>
</span>

Warning on console

div is not a valid child of span at /path/to/file.tsx:linenumber:position

Avoid escaping

All content of HTML tags and attributes are escaped by default to avoid XSS attacks. Similarly to React's dangerouslySetInnerHTML, you can disable escaping by using the raw function.

import { raw } from '@triptease/html-jsx';

const content = '<script>arbitraryCode()</script>';

<div>{content}</div> // Outputs <div>&lt;script&gt;arbitraryCode()&lt;&#x2F;script&gt</div>;
<div>{raw(content)}</div> // Outputs <div><script>arbitraryCode()</script></div>

Attribute escaping can also be disabled

import { raw } from '@triptease/html-jsx';

<hr data-x={raw('&')} /> // Outputs <hr data-x="&" />
<hr data-x={'&'} /> // Outputs <hr data-x="&amp;" />

Inline Javascript

TODO: Add documentation

Extend with Custom Elements

Define custom elements by extending the JSX.IntrinsicElements interface.

declare module '@triptease/html-jsx' {
  namespace JSX {
    interface IntrinsicElements {
      'some-custom-element': {
        someAttribute: string;
        children?: Children;
      };
    }
  }
}

<some-custom-element someAttribute="data">Foo</some-custom-element>