npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

pixel_cyber_link

v1.3.0

Published

Compose render prop components

Downloads

9

Readme

React Composer

Travis build status npm version npm downloads Test Coverage gzip size

Compose render prop components.

Motivation

Render props are great. Using a component with a render prop looks like the following:

<RenderPropComponent {...config}>
  {result => <MyComponent result={result} />}
</RenderPropComponent>

Sometimes you need the result of multiple render prop components inside of MyComponent. This can get messy.

<RenderPropComponent {...config}>
  {resultOne => (
    <RenderPropComponent {...configTwo}>
      {resultTwo => (
        <RenderPropComponent {...configThree}>
          {resultThree => (
            <MyComponent results={{ resultOne, resultTwo, resultThree }} />
          )}
        </RenderPropComponent>
      )}
    </RenderPropComponent>
  )}
</RenderPropComponent>

Nesting render prop components leads to rightward drift of your code. Use React Composer to prevent that drift.

import Composer from 'react-composer';

<Composer
  components={[
    <RenderPropComponent {...configOne} />,
    <RenderPropComponent {...configTwo} />,
    <RenderPropComponent {...configThree} />
  ]}>
  {([resultOne, resultTwo, resultThree]) => (
    <MyComponent results={{ resultOne, resultTwo, resultThree }} />
  )}
</Composer>;

Installation

Install using npm:

npm install react-composer

or yarn:

yarn add react-composer

API

This library has one, default export: Composer.

<Composer />

Compose multiple render prop components together. The props are as follows:

props.children

A render function that is called with an array of results accumulated from the render prop components.

<Composer components={[]}>
  {results => {
    /* Do something with results... Return a valid React element. */
  }}
</Composer>

props.components

The render prop components to compose. This is an array of React elements and/or render functions that are invoked with a render function and the currently accumulated results.

<Composer
  components={[
    // React elements may be passed for basic use cases
    // props.children will be provided via React.cloneElement
    <Outer />,

    // Render functions may be passed for added flexibility and control
    ({ results, render }) => (
      <Middle previousResults={results} children={render} />
    )
  ]}>
  {([outerResult, middleResult]) => {
    /* Do something with results... Return a valid React element. */
  }}
</Composer>

Note: You do not need to provide props.children to the React element entries in props.components. If you do provide props.children to these elements, it will be ignored and overwritten.

props.components as render functions

A render function may be passed instead of a React element for added flexibility.

Render functions provided must return a valid React element. Render functions will be invoked with an object containing 2 properties:

  1. results: The currently accumulated results. You can use this for render prop components which depend on the results of other render prop components.
  2. render: The render function for the component to invoke with the value produced. Plug this into your render prop component. This will typically be plugged in as props.children or props.render.
<Composer
  components={[
    // props.components may contain both elements and render functions
    <Outer />,
    ({ /* results, */ render }) => <SomeComponent children={render} />
  ]}>
  {results => {
    /* Do something with results... */
  }}
</Composer>

Examples and Guides

Example: Render prop component(s) depending on the result of other render prop component(s)

<Composer
  components={[
    <Outer />,
    ({ results: [outerResult], render }) => (
      <Middle fromOuter={outerResult} children={render} />
    ),
    ({ results, render }) => (
      <Inner fromOuterAndMiddle={results} children={render} />
    )
    // ...
  ]}>
  {([outerResult, middleResult, innerResult]) => {
    /* Do something with results... */
  }}
</Composer>

Example: Render props named other than props.children.

By default, <Composer /> will enhance your React elements with props.children.

Render prop components typically use props.children or props.render as their render prop. Some even accept both. For cases when your render prop component's render prop is not props.children you can plug render in directly yourself. Example:

<Composer
  components={[
    // Support varying named render props
    <RenderAsChildren />,
    ({ render }) => <RenderAsChildren children={render} />,
    ({ render }) => <RenderAsRender render={render} />,
    ({ render }) => <CustomRenderPropName renderItem={render} />
    // ...
  ]}>
  {results => {
    /* Do something with results... */
  }}
</Composer>

Example: Render prop component(s) that produce multiple arguments

Example of how to handle cases when a component passes multiple arguments to its render prop rather than a single argument.

<Composer
  components={[
    <Outer />,
    // Differing render prop signature (multi-arg producers)
    ({ render }) => (
      <ProducesMultipleArgs>
        {(one, two) => render([one, two])}
      </ProducesMultipleArgs>
    ),
    <Inner />
  ]}>
  {([outerResult, [one, two], innerResult]) => {
    /* Do something with results... */
  }}
</Composer>

Limitations

This library only works for render prop components that have a single render prop. So, for instance, this library will not work if your component has an API like the following:

<RenderPropComponent onSuccess={onSuccess} onError={onError} />

Render Order

The first item in the components array will be the outermost component that is rendered. So, for instance, if you pass

<Composer components={[<A/>, <B/>, <C/>]}>

then your tree will render like so:

- A
  - B
    - C

Console Warnings

Render prop components often specify with PropTypes that the render prop is required. When using these components with React Composer, you may get a warning in the console.

One way to eliminate the warnings is to define the render prop as an empty function knowning that Composer will overwrite it with the real render function.

<Composer
  components={[
    <RenderPropComponent {...props} children={() => null} />
  ]}
  // ...
>

Alternatively, you can leverage the flexibility of the props.components as functions API and plug the render function in directly yourself.

<Composer
  components={[
    ({render}) => <RenderPropComponent {...props} children={render} />
  ]}
  // ...
>

Example Usage

Here are some examples of render prop components that benefit from React Composer:

Do you know of a component that you think benefits from React Composer? Open a Pull Request and add it to the list!

Contributing

Are you interested in helping out with this project? That's awesome – thank you! Head on over to the contributing guide to get started.