- Table of Contents
- Installing
- Getting Started
- Sanitization
- Compiling html
- Fragments
- Supported HTML
- Kebab case
- Performance
- How it works
npm install @kitajs/html # or yarn add @kitajs/htmlInstall @kitajs/html with your favorite package manager, import it into the top of your jsx/tsx file and change your tsconfig.json to transpile jsx syntax.
// tsconfig.json
{
"compilerOptions": {
"jsx": "react",
"reactNamespace": "html"
}
}// Always remember to import html from '@kitajs/html'
import html from '@kitajs/html'
// Using as a simple html builder
console.log(<div>Hello World</div>) // '<div>Hello World</div>'
// Maybe your own server-side html api
function route(request, response) {
return response
.header('Content-Type', 'text/html')
.send(<div>Hello World</div>)
}
// Maybe in a static html file
fs.writeFileSync(
'index.html',
<html>
<head>
<title>Hello World</title>
</head>
<body>
<div>Hello World</div>
</body>
</html>
)
// Also as a component library
function Layout({ name, children }: html.PropsWithChildren<{ name: string }>) {
return (
<html>
<head>
<title>Hello World</title>
</head>
<body>
<div>Hello {name}</div>
{children}
</body>
</html>
)
}
console.log(<Layout name="World">I'm in the body!</Layout>)
// Anywhere you want! All JSX becomes a string
typeof (<div>Hello World</div>) === 'string'This package just provides functions to transpile JSX to a HTML string, you can imagine doing something like this before, but now with type checking and intellisense:
// without @kitajs/html
const html = `<div> Hello World!<div>` ❌// with @kitajs/html
const html = (<div>Hello World!<div>) ✅
// Also results into a string, but with type checked.This package is a HTML builder, not an HTML sanitizer. This means that it does not sanitize any input, and you should sanitize where its needed. However, we escape all attribute values to avoid breaking out of the html attribute/tag.
const script = '<script>alert("hacked!")</script>'
const html = (
<>
<div style={'"&<>\''}></div>
<div>{script}</div>
</>
)Will result into this html below but minified:
<!-- formatted html to make it easier to read -->
<div style=""&<>'"></div>
<div>
<script>
alert('hacked!')
</script>
</div>When you have static html, is simple to get amazing performances, just save it to a constant and reuse it. However, if you need to hydrate the html with dynamic values in a super fast way, you can use the compile property to compile the html and reuse it later.
import html from '@kitajs/html'
const compiled = html.compile<['param1', 'param2']>(
<div>
<div>$param1</div>
<div>$param2</div>
<div>$notFound</div>
</div>
)
const html = compiled({ param1: 'Hello', param2: 'World!' })
// formatted html to make it easier to read
// <div>
// <div>Hello</div>
// <div>World!</div>
// <div>$notFound</div>
// </div>This makes the html generation almost 3000x faster than just using jsx normally.
Variables that were not passed to the compile function are ignored silently, this way you can reuse the result into another compile function or just because the your "$val" was supposed to be a static value.
JSX does not allow multiple root elements, but you can use a fragment to group multiple elements:
const html = (
<>
<div>1</div>
<div>2</div>
</>
)Learn more about JSX syntax here!
All HTML elements and attributes are supported, except for the svg.
- Supported html elements: https://dev.w3.org/html5/html-author/#the-elements
- Supported html events: http://htmlcss.wikia.com/wiki/HTML5_Event_Attributes
Missing an element or attribute? Please create an issue or a PR to add it. It's easy to add.
HTML tags and attributes should be case insensitive, however JSX syntax does not allow <kebab-case> elements. Therefore we transform all <camelCase> tags into <camel-case> to allow usage of custom html tags.
This transformation also works for custom attributes you define on a custom element yourself. For example:
<kebabCase kebabCase="value"></kebabCase>Becomes
<kebab-case kebab-case="value"></kebab-case>Note, if you are using Typescript, you will have to extend JSX namespace to allow it:
interface MathPower {
myExponential: number
// this property becomes the children type
children: number
}
declare namespace JSX {
interface IntrinsicElements {
mathPower: MathPower
}
}
const element = <mathPower myExponential={2}>{3}</mathPower>
// Becomes <math-power my-exponential="2">3</math-power>This package is just a string builder on steroids, as you can see how this works. However we are running a benchmark with an JSX HTML with about 10K characters to see how it performs.
You can run this yourself by running pnpm bench.
@kitajs/html:
13 604 ops/s, ±1.12% | 99.97% slower
@kitajs/html - compiled:
38 938 712 ops/s, ±2.49% | fastest
typed-html:
10 057 ops/s, ±1.78% | slowest, 99.97% slowerThis can be easily done by using Typescript's JSX support and changing the default react bindings to our own html namespace.
<ol start={2}>
{[1, 2].map((i) => (
<li>{i}</li>
))}
</ol>Is transpiled by typescript compiler at build step to:
html.createElement(
'ol',
{ start: 2 },
[1, 2].map((i) => html.createElement('li', null, i))
)Which results into this string:
<ol start="2">
<li>1</li>
<li>2</li>
</ol>