HyperScript

Create HyperText with JavaScript, on client or server.

Interactive Demo

See also mercury, a modular ui framework influenced by hyperscript but much more heavily optimized.

Example

var h = require('hyperscript')
h('div#page',
  h('div#header',
    h('h1.classy', 'h', { style: {'background-color': '#22f'} })),
  h('div#menu', { style: {'background-color': '#2f2'} },
    h('ul',
      h('li', 'one'),
      h('li', 'two'),
      h('li', 'three'))),
    h('h2', 'content title',  { style: {'background-color': '#f22'} }),
    h('p',
      "so it's just like a templating engine,\n",
      "but easy to use inline with javascript\n"),
    h('p',
      "the intention is for this to be used to create\n",
      "reusable, interactive html widgets. "))

On the server

You can still use hyperscript on the server, the limitation is that events don't make sense anymore, but you can use it to generate html:

console.log(h('h1', 'hello!').outerHTML)
=> '<h1>hello!</h1>'

h (tag, attrs, [text?, Elements?,...])

Create an HTMLElement. The first argument must be the tag name, you may use a fully qualified tagname for building e.g. XML documents: `h('ns:tag').

classes & id

If the tag name is of form name.class1.class2#id that is a shortcut for setting the class and id.

default tag name

If the tag name begins with a class or id, it defaults to a <div>.

Attributes

If an {} object is passed in it will be used to set attributes.

var h = require('hyperscript')
h('a', {href: 'https://npm.im/hyperscript'}, 'hyperscript')

Note that hyperscript sets properties on the DOM element object, not attributes on the HTML element. This makes for better consistency across browsers and a nicer API for booleans. There are some gotchas, however. Attributes such as colspan are camel cased to colSpan, and for on the label element is htmlFor to avoid collision with the language keyword. See the DOM HTML specification for details.

events

If an attribute is a function, then it will be registered as an event listener.

var h = require('hyperscript')
h('a', {href: '#',
  onclick: function (e) {
    alert('you are 1,000,000th visitor!')
    e.preventDefault()
  }
}, 'click here to win a prize')

styles

If an attribute has a style property, then that will be handled specially.

var h = require('hyperscript')
h('h1.fun', {style: {'font-family': 'Comic Sans MS'}}, 'Happy Birthday!')

or as a string

var h = require('hyperscript')
h('h1.fun', {style: 'font-family: Comic Sans MS'}, 'Happy Birthday!')

You may pass in attributes in multiple positions, it's no problem!

children - string

If an argument is a string, a TextNode is created in that position.

children - HTMLElement

If a argument is a Node (or HTMLElement), for example, the return value of a call to h that's cool, too.

children - null.

This is just ignored.

children - Array

Each item in the array is treated like a ordinary child. (string or HTMLElement) this is useful when you want to iterate over an object:

var h = require('hyperscript')
var obj = {
  a: 'Apple',
  b: 'Banana',
  c: 'Cherry',
  d: 'Durian',
  e: 'Elder Berry'
}
h('table',
  h('tr', h('th', 'letter'), h('th', 'fruit')),
  Object.keys(obj).map(function (k) {
    return h('tr',
      h('th', k),
      h('td', obj[k])
    )
  })
)

Cleaning Up

If you need to clean up a widget created using hyperscript - deregistering all its event handlers and observable listeners, you can use context().

var h = require('hyperscript').context()
var o = require('observable')
var text = o()
text('click here to win a prize')
h('a', {href: '#',
  onclick: function (e) {
    text('you are 1,000,000th visitor!')
    e.preventDefault()
  }
}, text)

// then if you want to remove this widget from the page
// to cleanup
h.cleanup()

Ecosystem

• html2hscript - Parse HTML into hyperscript
• dom2hscript - Frontend library for parsing HTML into hyperscript using the browser's built in parser.
• html2hscript.herokuapp.com - Online Tool that converts html snippets to hyperscript
• html2hyperscript - Original commandline utility to convert legacy HTML markup into hyperscript
• hyperscript-helpers - write div(h1('hello') instead of h('div', h('h1', 'hello'))
• react-hyperscript - use hyperscript with React.

License

MIT