bel

bel

A simple library for composable DOM elements using tagged template strings.

If you're looking for a higher level front end framework, try yo-yo. Or even higher than that, try choo.

usage

For a more in depth tutorial on getting started, please check out the wiki.

A Simple Element

Create an element:

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

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

Then pass data to it and add to the DOM:

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

Data Down, Actions Up

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

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

// app.js
var bel = require('bel')
var morphdom = require('morphdom')
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
    morphdom(element, render(id))
  }
  function render (selected) {
    return bel`<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
}

lifecycle events

Use the onload and onunload properties to call a function when the element is inserted and removed from the DOM respectively.

var bel = require('bel')

var modal = bel`<div onload=${function (element) {
  console.log('Hello DOM!')
}} onunload=${function (element) {
  console.log('Goodbye DOM!')
}}>hello!</div>`

document.body.appendChild(modal)
document.body.removeChild(modal)

use with/without hyperx

hyperx is built into bel but there may be times when you wish to use your own version or implementation of hyperx. Or if you prefer to create elements using bel without using tagged template literals:

var createElement = require('bel').createElement
var hyperx = require('hyperx')
var bel = hyperx(createElement)

var element = bel`<div class="heading">Hello!</div>`

// ...

var sameElement = createElement('div', { className: 'heading' }, ['Hello!'])

similar projects

• vel
  minimal virtual-dom library
• base-element
  An element authoring library for creating standalone and performant elements
• virtual-dom
  A Virtual DOM and diffing algorithm
• hyperscript
  Create HyperText with JavaScript.

license

(c) 2016 Kyle Robinson Young. MIT License