vif

Vif is a Javascript library for building user interface.

• Functionnal: No object oriented programming pattern are needed to use Vif. The provided API do not include Class despite React does.
• Simple: Vif allow you to write simple code.

Installation

boilerplate

The boilerplate is not ready yet. It will provide a pre-configured node project with Webpack and Babel.

npm

$ npm install --save vif

To use vif with jsx you will need to add babel-plugin-transform-react-jsx to your .babelrc file with the following configuration:

{
  "plugins": [
    [
      "transform-react-jsx",
      {
          "pragma": "Vif.createElement"
      }
    ]
  ]
}

Usage

Hello world

The render function load the application in the DOM into a provided element.

import Vif from 'vif'

Vif.render(
  <span>Hello World!</span>,
  document.getElementById('app')
)

or

import Vif from 'vif'

const Hello = props => (
  <span>Hello {props.to}!</span>
)

Vif.render(
  <Hello to="World" />,
  document.getElementById('app')
)

Simple component

A simple component is a function with a single argument (props) that return JSX or a string.

more information about JSX

import Vif from 'vif'

const BigText = props => (
  <h1
    style={{
      color: props.color,
      fontSize: `${props.size}rem`
    }}
  >
    {props.children}
  </h1>
)

const App = props => (
  <div
    className="app"
  >
    <BigText
      color="orange"
      size={4}
    >
      Hi!
    </BigText>
  </div>
)

props

A prop can be of any type, it can even be a function. All tags declared between the opening and closing tags of Component are passed trough props in the property named children.

JSX obligation

import Vif from 'vif'

This import have to be in the scope of every component declaration in order to link JSX with vif.

Smart component

import Vif, { smart } from 'vif'

const humanizeLightState = isOn =>
  isOn ? 'on' : 'off'

const LightSwitch = actions => (props, state) => (
  <div
    className="LightSwitch"
  >
    <button onClick={actions.turnOn}>
      on
    </div>
    <div onClick={actions.turnOff}>
      off
    </div>
    <div onClick={actions.toggle}>
      toggle
    </div>
    <h1>light is {humanizeLightState(state.isOn)}</h1>
  </div>
)

const state = {
  isOn: false
}

const actions = {
  turnOn: () => ({
    isOn: true
  }),
  turnOff: () => ({
    isOn: false
  }),
  toggle: () => (state) => ({
    isOn: !state.isOn
  })
}

const lifecycle = {
  onUpdate: ({ lastState, nextState }) => {

    console.log(`The light was ${humanizeLightState(lastState.isOn)}.`)
    console.log(`It is now ${humanizeLightState(nextState.isOn)}.`)

  }
}

export default smart({ state, actions, lifecycle })(Counter)

state

The simplest way to declare state is with an object.

const state = {
  foo: 'bar'
}

State can be a function that will be called before component mounting with his initial props.

const state = (props) => ({
  foo: props.bar
})

actions

An action is a function that can be wrapped in another function.

const actions = {
  setCounterValue: value => ({
    value
  })
}

If the action return a function. This returned function will be called with two arguments: props and state.

const actions = {
  incrementCounter: () => (props, state) => ({
    value: state.value + 1
  })
}

Action can be asynchronous by returning a Promise.

const actions = {
  setCounterValue: value => new Promise(resolve =>
    setTimeout(() => {
      resolve({ value })
    }, 1000)
  ),
  incrementCounter: () => (props, state) => new Promise(resolve =>
    setTimeout(() => {
      resolve({ value: state.value + 1 })
    }, 1000)
  )
}

The readability of asynchronous action can be improved by using async and await keyword.

const delay = duration => new Promise(resolve => setTimeout(resolve, duration))

const actions = {
  setCounterValue: async (value) => {
    await delay(1000)
    return { value }
  },
  incrementCounter: () => async (props, state) => {
    await delay(1000)
    return { value: state.value + 1 }
  }
}

lifecycle

const lifecycle = {
  onMount: ({ props, state }) => {

  },
  onUpdate: ({ lastState, nextState, lastProps, nextProps }) => {

  },
  onUnmount: ({ props, state }) => {

  }
}

Roadmap

Code structure is a pre-lerna implementation.

Vif is still in an early development state. Some of the API are going to be changed and others will be implemented.

• [x] Implement asynchronous actions
• [ ] Add lerna
• [ ] Define proper lifecyle API
• [ ] Implement DOM element references API
• [ ] Create a boilerplate in its own git repository
• [ ] Create a clean documentation