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

react-side-effect

v2.1.2

Published

Create components whose prop changes map to a global side effect

Downloads

8,425,564

Readme

React Side Effect Downloads npm version

Create components whose prop changes map to a global side effect.

Installation

npm install --save react-side-effect

As a script tag

Development

<script src="https://unpkg.com/react/umd/react.development.js" type="text/javascript"></script>
<script src="https://unpkg.com/react-side-effect/lib/index.umd.js" type="text/javascript"></script>

Production

<script src="https://unpkg.com/react/umd/react.production.min.js" type="text/javascript"></script>
<script src="https://unpkg.com/react-side-effect/lib/index.umd.min.js" type="text/javascript"></script>

Use Cases

  • Setting document.body.style.margin or background color depending on current screen;
  • Firing Flux actions using declarative API depending on current screen;
  • Some crazy stuff I haven't thought about.

How's That Different from componentDidUpdate?

It gathers current props across the whole tree before passing them to side effect. For example, this allows you to create <BodyStyle style> component like this:

// RootComponent.js
return (
  <BodyStyle style={{ backgroundColor: 'red' }}>
    {this.state.something ? <SomeComponent /> : <OtherComponent />}
  </BodyStyle>
);

// SomeComponent.js
return (
  <BodyStyle style={{ backgroundColor: this.state.color }}>
    <div>Choose color: <input valueLink={this.linkState('color')} /></div>
  </BodyStyle>
);

and let the effect handler merge style from different level of nesting with innermost winning:

import { Component, Children } from 'react';
import PropTypes from 'prop-types';
import withSideEffect from 'react-side-effect';

class BodyStyle extends Component {
  render() {
    return Children.only(this.props.children);
  }
}

BodyStyle.propTypes = {
  style: PropTypes.object.isRequired
};

function reducePropsToState(propsList) {
  var style = {};
  propsList.forEach(function (props) {
    Object.assign(style, props.style);
  });
  return style;
}

function handleStateChangeOnClient(style) {
  Object.assign(document.body.style, style);
}

export default withSideEffect(
  reducePropsToState,
  handleStateChangeOnClient
)(BodyStyle);

On the server, you’ll be able to call BodyStyle.peek() to get the current state, and BodyStyle.rewind() to reset for each next request. The handleStateChangeOnClient will only be called on the client.

API

withSideEffect: (reducePropsToState, handleStateChangeOnClient, [mapStateOnServer]) -> ReactComponent -> ReactComponent

A higher-order component that, when mounting, unmounting or receiving new props, calls reducePropsToState with props of each mounted instance. It is up to you to return some state aggregated from these props.

On the client, every time the returned component is (un)mounted or its props change, reducePropsToState will be called, and the recalculated state will be passed to handleStateChangeOnClient where you may use it to trigger a side effect.

On the server, handleStateChangeOnClient will not be called. You will still be able to call the static rewind() method on the returned component class to retrieve the current state after a renderToString() call. If you forget to call rewind() right after renderToString(), the internal instance stack will keep growing, resulting in a memory leak and incorrect information. You must call rewind() after every renderToString() call on the server.

For testing, you may use a static peek() method available on the returned component. It lets you get the current state without resetting the mounted instance stack. Don’t use it for anything other than testing.

Usage

Here's how to implement React Document Title (both client and server side) using React Side Effect:

import React, { Children, Component } from 'react';
import PropTypes from 'prop-types';
import withSideEffect from 'react-side-effect';

class DocumentTitle extends Component {
  render() {
    if (this.props.children) {
      return Children.only(this.props.children);
    } else {
      return null;
    }
  }
}

DocumentTitle.propTypes = {
  title: PropTypes.string.isRequired
};

function reducePropsToState(propsList) {
  var innermostProps = propsList[propsList.length - 1];
  if (innermostProps) {
    return innermostProps.title;
  }
}

function handleStateChangeOnClient(title) {
  document.title = title || '';
}

export default withSideEffect(
  reducePropsToState,
  handleStateChangeOnClient
)(DocumentTitle);