Dynamic-Context-Provider

With the context api some familiar patterns began popping up. Create a Context, Provider, a reducer and state objects. This is fine, but say you have multiple pages and want each to have their own context, you can easily find yourself in boilerplate land. Luckily, with this package you won't have that issue!

This package utilizes Reacts context API, if you're not familiar with it, here's some good ole' docs!

Run

To run the examples provided in this project, cd into the example folder and run npm start. Or in the root you can run cd example && npm start

Use

import { ContextStateProvider, useContextState } from 'dynamic-context-provider'

Instead of creating multiple contexts, reducers etc, we simply reuse the same Provider and pass it a different stateConfig. The provider will create a reducer and state objects based off the config and the state will be accessible in the useContextState hook.

import * as React from 'react';
import { ContextStateProvider, useContextState } from 'dynamic-context-provider';

const exampleConfig ={
  first: 'Megaman', last: 'isTheBest'
}
const exampleConfig2 ={
  count: 0
}
const App = () => {
  return (
    <div>
      <ContextStateProvider stateConfig={exampleConfig}>
        <Example />
      </ContextStateProvider>
      <ContextStateProvider stateConfig={exampleConfig2}>
        <Example2 />
      </ContextStateProvider>
    </div>
  );
};

const Example = () => {
  const {first, last} = useContextState()
  return(
    <div>
      {first} {last}
    </div>
  )
}
const Example2 = () => {
  const {count} = useContextState()
  return(
    <div>
      {count}
    </div>
  )
}

Updating each individual instance of the dynamic context is also simple with the updateContextState function, that's accessible from useContextState.

import { useContextState } from 'dynamic-context-provider';

const Example2 = () => {
const { count, updateContextState } = useContextState()
function increaseCount(){
  let newCount = count
  updateContextState({count: newCount+=1 })
}
return(
  <div>
    {count}
    <button onClick={increaseCount}>+</button>
  </div>
)
}
// you can also update multiple states at once, example: updateContextState({first: 'new', last: 'name'})

There may be times when you would like functions accessible to all the children your dynamic context parents. This is possible via the globalFunctions prop. This prop provides you with access to the context providers current state and the updateContextState function.

import 'react-app-polyfill/ie11';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { ContextStateProvider, useContextState } from '../.';

const exampleConfig3 ={
pokemonInfo: 0,
isLoadingPokemonInfo: false
}
const globalFunctions = (props: any) => {
async function getPokemonInfo(name: string) {
  let pokemonInfo = { error: true }
  props.updateContextState({ isLoadingPokemonInfo: true })

  try {
    const data = await fetch(`https://pokeapi.co/api/v2/pokemon/${name.toLocaleLowerCase()}`)
    pokemonInfo = await data.json()
  } catch (e) {
    console.error('There was an error', e)
  }
  props.updateContextState({ pokemonInfo, isLoadingPokemonInfo: false })
}
return {
  getPokemonInfo
}
}
const App = () => {
return (
  <div>
    <ContextStateProvider globalFunctions={globalFunctions} stateConfig={exampleConfig3}>
      <Example3 />
    </ContextStateProvider>
  </div>
);
};

const Example3 = () => {
const { pokemonInfo, isLoadingPokemonInfo, getPokemonInfo } = useContextState()
const [pokemonName, setPokemonName] = React.useState('')
async function handleClick() {
  await getPokemonInfo(pokemonName)
}
if (isLoadingPokemonInfo) {
  return <div>Loading...</div>
}
return (
  <>
    <div>
      <input name="pokemonName" onChange={(e: any) => setPokemonName(e.target.value)} value={pokemonName} type="text" />
      <button type="button" onClick={handleClick}>Search pokemon</button>
    </div>
    {
      pokemonInfo.error && <div>Error finding pokemon</div>
    }
    {pokemonInfo.name &&
      <div style={{ display: 'flex', alignItems: 'center' }}>
        <img src={pokemonInfo.sprites.front_shiny} />
        <span> {pokemonInfo.order}</span>: {pokemonInfo.name}

      </div>

    }
  </>

)
}

This project also supports caching via sessionStorage, so if you ever want to store your state you can add a cacheStateKey

<ContextStateProvider cacheStateKey="homePageCache" stateConfig={homePageConfig}>
      <HomePage />
    </ContextStateProvider>

Provider props

ContextStateProvider {
    children: React.ReactNode,
    stateConfig: object,
    cacheStateKey?: string,
    globalFunctions?: ({state, updateContextState}: {state: any, updateContextState: any})=>object, // return an object containing functions

This was bootstrapped using TSDX, here's some of the wonderful features that comes along with their excellent project:

Commands

TSDX scaffolds your new library inside /src, and also sets up a Parcel-based playground for it inside /example.

The recommended workflow is to run TSDX in one terminal:

npm start # or yarn start

This builds to /dist and runs the project in watch mode so any edits you save inside src causes a rebuild to /dist.

Then run the example inside another:

cd example
npm i # or yarn to install dependencies
npm start # or yarn start

The default example imports and live reloads whatever is in /dist, so if you are seeing an out of date component, make sure TSDX is running in watch mode like we recommend above. No symlinking required, we use Parcel's aliasing.

To do a one-off build, use npm run build or yarn build.

To run tests, use npm test or yarn test.

Configuration

Code quality is set up for you with prettier, husky, and lint-staged. Adjust the respective fields in package.json accordingly.

Jest

Jest tests are set up to run with npm test or yarn test.

Setup Files

This is the folder structure we set up for you:

/example
  index.html
  index.tsx       # test your component here in a demo app
  package.json
  tsconfig.json
/src
  index.tsx       # EDIT THIS
/test
  blah.test.tsx   # EDIT THIS
.gitignore
package.json
README.md         # EDIT THIS
tsconfig.json

React Testing Library

We do not set up react-testing-library for you yet, we welcome contributions and documentation on this.

Rollup

TSDX uses Rollup as a bundler and generates multiple rollup configs for various module formats and build settings. See Optimizations for details.

TypeScript

tsconfig.json is set up to interpret dom and esnext types, as well as react for jsx. Adjust according to your needs.

Continuous Integration

GitHub Actions

A simple action is included that runs these steps on all pushes:

• Installs deps w/ cache
• Lints, tests, and builds

Optimizations

Please see the main tsdx optimizations docs. In particular, know that you can take advantage of development-only optimizations:

// ./types/index.d.ts
declare var __DEV__: boolean;

// inside your code...
if (__DEV__) {
  console.log('foo');
}

You can also choose to install and use invariant and warning functions.

Module Formats

CJS, ESModules, and UMD module formats are supported.

The appropriate paths are configured in package.json and dist/index.js accordingly. Please report if any issues are found.

Deploying the Example Playground

The Playground is just a simple Parcel app, you can deploy it anywhere you would normally deploy that. Here are some guidelines for manually deploying with the Netlify CLI (npm i -g netlify-cli):

cd example # if not already in the example folder
npm run build # builds to dist
netlify deploy # deploy the dist folder

Alternatively, if you already have a git repo connected, you can set up continuous deployment with Netlify:

netlify init
# build command: yarn build && cd example && yarn && yarn build
# directory to deploy: example/dist
# pick yes for netlify.toml

Named Exports

Per Palmer Group guidelines, always use named exports. Code split inside your React app instead of your React library.

Including Styles

There are many ways to ship styles, including with CSS-in-JS. TSDX has no opinion on this, configure how you like.

For vanilla CSS, you can include it at the root directory and add it to the files section in your package.json, so that it can be imported separately by your users and run through their bundler's loader.

Publishing to NPM

We recommend using np.

Usage with Lerna

When creating a new package with TSDX within a project set up with Lerna, you might encounter a Cannot resolve dependency error when trying to run the example project. To fix that you will need to make changes to the package.json file inside the example directory.

The problem is that due to the nature of how dependencies are installed in Lerna projects, the aliases in the example project's package.json might not point to the right place, as those dependencies might have been installed in the root of your Lerna project.

Change the alias to point to where those packages are actually installed. This depends on the directory structure of your Lerna project, so the actual path might be different from the diff below.

   "alias": {
-    "react": "../node_modules/react",
-    "react-dom": "../node_modules/react-dom"
+    "react": "../../../node_modules/react",
+    "react-dom": "../../../node_modules/react-dom"
   },

An alternative to fixing this problem would be to remove aliases altogether and define the dependencies referenced as aliases as dev dependencies instead. However, that might cause other problems.