bel/README.md

# [bel](https://en.wikipedia.org/wiki/Bel_(mythology))

[![NPM version][npm-image]][npm-url]
[![build status][travis-image]][travis-url]
[![Downloads][downloads-image]][downloads-url]
[![js-standard-style][standard-image]][standard-url]
![experimental][experimental-image]

A simple library for composable DOM elements using [tagged template strings](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals).

## usage

### A Simple Element

Create an element:

```js
// list.js
var $ = require('bel')

module.exports = function (items) {
  return $`<ul>
    ${items.map(function (item) {
      return $`<li>${item}</li>`
    })}
  </ul>`
}
```

Then pass data to it and add to the DOM:

```js
// app.js
var createList = require('./list.js')
var list = createList([
  'grizzly',
  'polar',
  'brown'
])
document.body.appendChild(list)
```

### Data Down, Actions Up

```js
// list.js
var $ = require('bel')

// The DOM is built by the data passed in
module.exports = function (items, onselected) {
  function render () {
    return $`<ul>
    ${items.map(function (item) {
      return $`<li>${button(item.id, item.label)}</li>`
    })}
    </ul>`
  }
  function button (id, label) {
    return $`<button onclick=${function () {
      // Then action gets sent up
      onselected(id)
    }}>${label}</button>`
  }
  var element = render()
  return element
}
```

```js
// app.js
var $ = require('bel')
var list = require('./list.js')

module.exports = function (bears) {
  function onselected (id) {
    // When a bear is selected, rerender with the newly selected item
    // This will use DOM diffing to render, sending the data back down again
    element.update(render(id))
  }
  function render (selected) {
    return $`<div className="app">
      <h1>Selected: ${selected}</h1>
      ${list(bears, onselected)}
    </div>`
  }
  // On first render, we haven't selected anything
  var element = render('none')
  return element
}
```

## similar projects

* [vel](https://github.com/yoshuawuyts/vel)  
  minimal virtual-dom library
* [base-element](https://github.com/shama/base-element)  
  An element authoring library for creating standalone and performant elements
* [virtual-dom](https://github.com/Matt-Esch/virtual-dom)  
  A Virtual DOM and diffing algorithm

# license
(c) 2016 Kyle Robinson Young. MIT License

[npm-image]: https://img.shields.io/npm/v/bel.svg?style=flat-square
[npm-url]: https://npmjs.org/package/bel
[travis-image]: https://img.shields.io/travis/shama/bel/master.svg?style=flat-square
[travis-url]: https://travis-ci.org/shama/bel
[downloads-image]: http://img.shields.io/npm/dm/vel.svg?style=flat-square
[downloads-url]: https://npmjs.org/package/bel
[standard-image]: https://img.shields.io/badge/code%20style-standard-brightgreen.svg?style=flat-square
[standard-url]: https://github.com/feross/standard
[experimental-image]: https://img.shields.io/badge/stability-experimental-orange.svg?style=flat-square