Longwood useState

Simple React useState and context like state management library for Longwood

Example

createState

You can use the createState function to create a useState function:

const app = createRenderTarget()
const useState = createState(0)
const render = div(
  useState((state, setState) =>
    div(
      text(`Count: ${state}`),
      button({
        id: 'button',
        onclick: () => setState(state + 1),
        children: [text('+1')]
      })
    )
  )
)

The useState function exposes state and setState arguments to the callback, which you can use to manage your component-specific state.

▶️ Run in CodeSandbox.io

createContext

You can use createContext function to craete a context object with state:

const { provider, consumer } = createContext(0)
const render = provider(
  div(
    consumer((state, setState) =>
      div(
        text(`Count: ${state}`),
        button({
          onclick: () => setState(state + 1),
          children: [text('+1')]
        })
      )
    )
  )
)
render(app)

You can then modify the state and the provider automatically re-renders the DOM.

▶️ Run in CodeSandbox.io

TODO app example

You can check out a full TODO app example:

▶️ Run in CodeSandbox.io

Getting started (ES Modules)

longwood-usestate is available as ES module, so quickest way to get started is to import the module directly within your HTML page:

<html>
  <body>
    <div id="app"></div>
    <script type="module">
      import { div, button } from 'https://cdn.skypack.dev/longwood'
      import { createState } from 'https://cdn.skypack.dev/longwood-usestate'

      const useState = createState(0)
      const render = div(
        useState((state, setState) =>
          div(
            text(`Count: ${state}`),
            button({
              onclick: () => setState(state + 1),
              children: [text('+1')]
            })
          )
        )
      )
      render(document.getElementById('app'))
    </script>
  </body>
</html>

▶️ Run in CodeSandbox.io

This is literally all the code you'll need! No build tools needed, no extra steps, just save the code as a .html file and start hacking.

Getting started (npm)

You can install longwood-usestate to your project like a normal dependency within your project:

yarn add longwood longwood-usestate

Then you can import the package in your js file. For example if you're using Webpack, you can do:

import { div } from 'longwood'
import { useState } from 'longwood-usestate'

const useState = createState(0)
const render = div(
  useState((state, setState) =>
    div(
      text(`Count: ${state}`),
      button({
        onclick: () => setState(state + 1),
        children: [text('+1')]
      })
    )
  )
)
render(document.getElementById('app'))

Developing

You can use TDD for development by running:

yarn
yarn test --watch

This runs Jest, and the tests use JSDOM for asserting how DOM looks like.

Building

You can build the project by running:

yarn build

This builds the project into build/ directory.

Deploying

This project is automatically deployed to NPM by using Travis CI. All tagged versions are published when pushed.

Don't add tags by hand! Run:

yarn release

This will run an interactive deploy script to help you deploy the most recent version.

Contributing

This is a very early version of the project, and all feedback is welcome. Please open an issue before implementing, as the direction still needs some adjustments.

Licensing

The code in this project is licensed under MIT license.