Render This

Lightweight React State Management Library

Author Ben Turner

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npm i render-this

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Table of Contents

• What?
• How?
• Why?
• Get Started
• Api Reference
• Changelog
• Upcoming Features

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What?

render-this is a React state management tool for easily managing large or complex nested states. Additionally, it reduces the boilerplate code necessary for tools like Redux.

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How?

render-this aggregates all the states and methods of arbitrarily many React components into a single consumable object, accessible via a very simple function called connect

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Why?

The philosophy of render-this is keep things simple.

So you have a component. You want its state and methods to be available to all other components regardless of their location in the tree. You likely have two options:

• Refactor it into redux using reducers/action creators.
  • BUT This requires a lot of boilerplate and perhaps learning a whole new design pattern.
• Use the new Context API and create your own global state component.
  • This can get large and unwieldy fast.
  • Even with multiple smaller ones the Provider components start stacking up.

render-this essentially does this the second option for you. You simply broadcast which components you want to be globally available and all states/methods will be combined into a single consumable object accessible through connect

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Get Started

First, wrap the application in the GlobalState component.

import GlobalState from "render-this";

ReactDOM.render(
  <GlobalState>
    <App />
  <GlobalState />
)

In order for a component to communicate with GlobalState, simply return its this value from render props:

class Auth extends Component {
  constructor() {
    super()
    this.state = {
      user: null
    }
    // GlobalState binds each method for you
  }
  login(user) {
    this.setState({ user })
  }
  logout() {
    this.setState({ user: null })
  }
  render() {
    // GlobalState needs `this` in order to access its state and methods. 
    return this.props.render(this);
  }
}

Next just add Auth to the components array prop on GlobalState:

import GlobalState from "render-this";

ReactDOM.render(
  //each component must be class-based!
  <GlobalState components={[Auth]}>
    <App />
  <GlobalState />
)

Elsewhere in your app, use the connect function to access all the methods on Auth as well as its current state. Notice that the props passed to login is called auth, which is just the camelCased name of the component Auth (the next version will allow for custom naming).

By default the entire state is passed down, but you can explicitly pick and choose which part of state you need. See connect below.

import { connect } from "render-this";

function Login(props) {
  return (
    <form onSubmit={() => props.auth.login({ username: "btdev" })}>
      <input type="text" placeholder="Username"/>
      <button>Login</button>
      <button type="button" onClick={props.auth.logout}>Logout, {props.auth.user && props.auth.user.username}</button>
    </form>
  )
}

export default connect(Login);

This pattern can be repeated as many times as you wish for any number of components. Just add them to the components array prop in GlobalState

import GlobalState from "render-this";

ReactDOM.render(
  <GlobalState components={[Auth, Images, Comments]}>
    <App />
  <GlobalState />
)

In this example, connect would attach an object to props which looks something like this:

console.log(props)
/*  {
//    auth: { /* ... */ },
//    images: { /* ... */ },
//    comments: { /* ... */}
//  }

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API Reference

§ <GlobalState>

Wrapper component which provides a React App with global state.

Props

Name	Type	Default Value	Description
components [optional]	Array	[]	Array of React class-based components to be added to the global state.
children [required]	element	N/A	The portion of the React tree to which the global state will be exposed

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§ connect

HOC which adds global state object to props.

Args

Name	Type	Default Value	Description
Component [required]	React Component	N/A	React Component to be provided props containing the global state.
mapStateToProps [optional]	callback	state => state	The portion of the React tree to which the global state will be exposed. Must return a javascript object.

// will attach only the state.auth object onto props of <Login>
connect(Login, state => state.auth);

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Changelog

• 9/29 - Initial commit and README

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Upcoming Features

• Ability to add custom names of keys of the global state object instead of the default camelCased component name

• Built-in normalization method for easily flattening nested data.