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stage0

Collection of low-level DOM tools for building high performance web interfaces using plain old Vanilla JS.

Eh?

Given a function h for building and working with the DOM nodes, organize your work however you like and use the full power of the native DOM API.

Benefits

Check out the examples

How can I use it?

Let's build a simple counter as an example:

import h from 'stage0'

// Create view template.
// Mark dynamic references with a #-syntax where needed.
const view = h`
  <div>
    <h1>#count</h1>
    <button #down>-</button>
    <button #up>+</button>
  </div>
`
function Main() {
    const root = view

    // Collect references to dynamic parts
    const {count, down, up} = view.collect(root)

    const state = {
        count: 0
    }

    down.onclick = () => {
        state.count--
        update()
    }

    up.onclick = () => {
        state.count++
        update()
    }

    const update = () => count.nodeValue = state.count
    update()

    return root
}

document.body.appendChild(Main())

A more complex example:

import h from 'stage0'

const itemView = h`
  <tr>
      <td class="col-md-1">#id</td>
      <td class="col-md-4">
          <a #select>#label</a>
      </td>
      <td class="col-md-1"><a #del><span class="glyphicon glyphicon-remove" aria-hidden="true"></span></a></td>
      <td class="col-md-6"></td>
  </tr>
`
function Item(item, scope) {
  const root = itemView
  const {id, label, select, del} = itemView.collect(root)

  // One time data binding
  id.nodeValue = item.id
  label.nodeValue = item.label
  select.onclick = () => scope.select(item)
  del.onclick = () => scope.del(item)

  // Handcrafted update function, we know exactly what parts of component will change after creation
  // and what parameters we need to update the view
  let a = '', a2,
      b = item.label, b2
  root.update = function(selected) {
    a2 = item.id === selected ? 'danger' : ''
    b2 = item.label

    if (a2 !== a) a = root.className = a2
    if (b2 !== b) b = label.nodeValue = b2
  }

  return root
}

// Create component
const node = Item({id: 1, label: 'Wow'}, {
    select: item => console.debug({item}),
    del: item => console.debug({item})
})
document.body.appendChild(node)

// And update the node
const selected = 1
node.update(selected)

h

import h from 'stage0'

const node = h`
    <div #root>
        <span>#header</span>
        <div #content></div>
    </div>
`
// will give you a ready to use DOM node, which you can clone or append directly wherever you need

// h augments the dom node with a function `collect` which collects and memoizes references to DOM nodes

const refs = node.collect(node)
// refs === {root: Node, header: Node, content: Node}

setupSyntheticEvent

import {setupSyntheticEvent} from 'stage0/syntheticEvents'

setupSyntheticEvent('click')
// will setup a global event handler that will run the handler from nearest predecessor in the DOM tree,
// greatly reducing the number of listeners on the page

// To attach an event handler to a dom node, simply do
node.__click = () => console.debug('click')

reconcile

import reconcile from 'stage0/reconcile'

// Reconcile nodes in the given parent, comparing new and previous data arrays.
// Used for displaying node arrays.
// Good for arrays with mutable data, because it compares array items directly.
reconcile(
    parent,
    renderedValues,
    newValues,
    // Create callback
    item => document.createTextNode(item),
    // Optional, update callback
    (node, item) => node.nodeValue = item + ' !!!',
    // Optional, node that comes before rendered list
    beforeNode,
    // Optional, node that comes after rendered list
    afterNode
)

keyed

import keyed from 'stage0/keyed'

// Reconcile implementation for keyed collections.
// Good for immutable data arrays.
keyed(
    'id',
    parent,
    renderedValues,
    newValues,
    // Create callback
    item => document.createTextNode(item),
    // Optional, update callback
    (node, item) => node.nodeValue = item + ' !!!',
    // Optional, node that comes before rendered list
    beforeNode,
    // Optional, node that comes after rendered list
    afterNode
)

reuseNodes

import reuseNodes from 'stage0/reuseNodes'

// Similar to reconcile, with exception that it will not move any node,
// doing only updates on all nodes and adding/removing nodes if neccessary.
// Used as more performant alternative of reconcile.
// Same as reconcile, it's designed for arrays with mutable items.
reuseNodes(
    parent,
    renderedValues,
    newValues,
    // Create callback
    item => document.createTextNode(item),
    // Optional, update callback
    (node, item) => node.nodeValue = item + ' !!!',
    // Optional, node that comes before rendered list
    beforeNode,
    // Optional, node that comes after rendered list
    afterNode
)

styles

import styles from 'stage0/styles'

// Small CSS-in-JS utility for generating classNames and corresponding cssRules in document.head
const s = styles({
    base: {
        display: 'flex',
        // pseudo-classes and pseudo-selectors are supported
        '::before': {
            content: '>'
        },
        // Nested selectors also supported
        ' > div': {
          color: '#DDDDDD'
        }
    }
})
// s will have s.base === 'base-a'
// styles will generate uniq alphabet tokens and append it to the end of className

keyframes

import {keyframes} from 'stage0/styles'

// Utility for generating keyframes, similar to `styles`
const s = keyframes({
    effect: {
        0: {
          display: 'flex'
        },
        100: {
          display: 'none'
        }
    }
})
// s will have s.effect === 'effect-a'